Exploring an Animalistic, Trauma-Informed Framework to Understand Depression, and the Need for Effective, Non-Traditional Psychotherapeutic Interventions That Attend to Physiological Processes

Abstract

Drawing on historical and current medical model trends, as well as the epistemologies and their impact for how we understand depression, leads to the crucial question for whether depression is a permanent or curable human phenomenon. Presenting animalistic and evolutionary perspectives within a biopsychosocial framework offers choice to individuals experiencing depression, that symptoms may be inherently fluid and a temporary part of the human condition. Furthermore, that early childhood attachment and trauma can shape our predisposition for experiencing depression is discussed. Neurobiological and neurochemical processes are identified as driving factors for depression from a trauma-informed lens, and psychotherapies that incorporate animal, nature, and somatic elements are offered as alternatives for supporting a biopsychosocial, body-based way of working with depression.

1. Introduction

For the last half century, the medical understanding of depression has generally dictated the definitive models, treatment and discourse used within society today, with little consideration for a biopsychosocial influence [1]. With an ever-growing body of research that is challenging these fundamental frameworks and understanding of depression, there is much need to review and consider additional ways of understanding depression and efficacious treatment applications.

Depression, understood as a mood disorder, is both a medical and lay-person term for a broad range of symptoms [2]. According to the American Psychological Association [3]:

“Depressive disorders include disruptive mood dysregulation disorder, major depressive disorder (including major depressive episode), persistent depressive disorder, premenstrual dysphoric disorder, substance/medication-induced depressive disorder, depressive disorder due to another medical condition, other specified depressive disorder, and unspecified depressive disorder. The common feature of all of these disorders is the presence of sad, empty, or irritable mood, accompanied by related changes that significantly affect the individual’s capacity to function (e.g., somatic and cognitive changes in major depressive disorder and persistent depressive disorder). What differs among them are issues of duration, timing, or presumed etiology” (Table 1).

The World Health Organisation (WHO)

Centers for Disease Control (CDC)

Poor concentration Feelings of excessive guilt or low self-worth Hopelessness about the future Thoughts about dying or suicide Disrupted sleep Changes in appetite or weight Feeling very tired or low in energy

Feeling sad or anxious often or all the time Not wanting to do activities that used to be fun Feeling irritable‚ easily frustrated‚ or restless Having trouble falling asleep or staying asleep Waking up too early or sleeping too much Eating more or less than usual or having no appetite Experiencing aches, pains, headaches, or stomach problems that do not improve with treatment Having trouble concentrating, remembering details, or making decisions Feeling tired‚ even after sleeping well Feeling guilty, worthless, or helpless Thinking about suicide or hurting yourself

Table 1.

Symptoms of depression.

The World Health Organisation (WHO) [4]; Centers for Disease Control (CDC) [5].

Although generally pathologised in our society through over-reliance of the medical model [6], it is widely understood that the symptoms of depression fall into many other categories of diagnosis, and as descriptors for other disorders [7]. It is, and has therefore been open to debate for decades as to whether depression is simply a part of the human condition [8].

2. Traditional and current medical model concepts for depression

According to Hindmarch [9], one of the oldest, and most widely used theories for national healthcare systems around the world for treating depression, is the Monoamine Hypothesis [10]. This theory understands depression as being caused by a neurotransmitter depletion of serotonin, dopamine and norepephrine in the nervous system, which among other properties, serves to regulate mood. To put this literally, it is argued that depressive feelings and behaviours occur as a result of a chemical imbalance within the person, consistent with the individualistically positioned medical model approach, going as far as to say that depression is a disease and life-long disability [11].

Historically, the evidence base for the monoamine theory was driven by reported effects of anti-depressants, specifically, selective serotonin re-uptake inhibitors (SSRI), which provide synthetic serotonin to the brain, relieving depressive symptoms. According to Hillhouse and Porter [12], after almost half a century, treating depressive symptoms with anti-depressants based on the monoamine hypothesis, has shown that recovery rates are often less than 60%, and where symptoms may be alleviated from this methodology, there is a delayed onset prior to recovery. Delgado [13] argues that there is insufficient evidence to support the theory that patients with major depressive disorders have an underlying monoamine dysfunction, due to the ‘absence of direct measurements of monoamines in humans’ not being recordable. Furthermore, that studies have found dysfunctional monoamine levels in people who are functioning typically, and not ever suffered with depressive symptoms, discredits the cause for depression as being solely due to a neurotransmitter chemical imbalance.

The monoamine hypothesis has contributed important findings to depression research which has led to more recent understandings for SSRIs influencing key neuroplasticity areas which improve depression- related symptoms [14]. According to Price and Dunman’s [15] Integrative Model of Neuroplasticity, the brain-derived neurotrophic factor (BDNF) theory suggests that SSRIs are beneficial in transducing the neuroplasticity changes that are needed to improve symptoms of mild and chronic depression caused by severe stress, as opposed to offering an effective solution for neurotransmitter chemical depletion, in line with Delgado’s [13] hypothesis. Specifically, hippocampal and cortical atrophy has been found to correlate with and represent depressive behaviours, and research over the past decade purports the efficacy of SSRIs, as well as ketamine for improving atrophy in BDNF expression and signalling in people with depression, suggesting a plausible neurological explanation.

In line with the SSRI treatment protocol, which proposes that the aetiology lays within the person, the National Institute for Clinical Excellence (NICE) [16] in the UK, recommends antidepressants and Cognitive Behavioural Therapy as the recommended treatment protocol for varying levels of depressive disorders. Cognitive psychotherapy treatment models such as Beck [17] understand all symptoms of depression, including biological factors such as loss of appetite and sleep disturbance; systemic factors, such as interpersonal relationships and work environment, as being consequential to a person’s core beliefs and negative thinking patterns about themselves and their lived existence. In its basic form, it is inferred that the negative cognitive appraisals create and maintain feelings of depression, and behaviours relating to the feeling and thought. Furthermore, that people with depressive tendencies hold a negative attention bias with cognitive distortions, which alongside the feelings and behaviours that follow, create a self-fulfilling prophecy. In short, it is therefore hypothesised that if the core beliefs can be established and changed, the feelings and behaviours that are maintaining the depression will also change. This approach fits an individualistic, pathologising paradigm consistent with the medical model, suggesting again, that the person (or at least their thinking) is faulty, and the issue lays within them. This way of understanding depression as it relates to a person’s existence in the world, negates the potential for other environmental and systemic influences as attributing towards the cause for the depression, and instead places salience on the neurological, cognitive and psychological function of the person (e.g., [18]).

In keeping with the medical model approach to assessing depression, is Beck et al. [19] psychometric scale, known as the ‘Depression Inventory’, which despite its age, is still globally used today to determine if a person qualifies for a diagnosis of depression. Psychometric measures and diagnosis offer an understanding or explanation for a person’s symptoms, and as such can sometimes be experienced as a relief for the individual [20]. Furthermore, within the realms of understanding a person’s symptomatology in this way, a psychological diagnosis has the potential to form an evidence-based treatment plan, which Paul [21] set about to create by asking the following question: “What treatment, by whom, is most effective for this individual with that specific problem, under which set of circumstances, and how does it come about?” (p. 44). Whilst a poignant piece of research at the time, both impacting and improving world-wide access to evidence-based psychotherapies, it also pushed a psychiatric, thus medical model bias towards treatment options for depression, through a heavy lenience on random-control based research, that focused on the symptoms and treatment protocol only. Assuming a position of diagnosis for depression begs the question as to whether the outlook for prognosis offers recovery, cure or a lifelong disability, thus limiting options for individual lived-experience. It could further be argued that the existential meanings that can be derived from such a label, for example: hopelessness (one of the main symptoms of depression), and the impact of living with a life-long diagnosis/label of depression, may also be founded by this methodology, creating a maintenance type cycle of hopelessness/depression [22]. In other words, in providing a diagnostic approach to depression and using the evidence-based treatment protocols, this approach may cease to take into account other environmental, systemic and interpersonal factors that might influence a person’s depression, and by denying these aspects, presents a dilemma for whether a diagnostic approach of depression limit’s a person’s ability to recover.

Johnstone [23] discusses at length the largely accumulated evidence-base for psychiatric diagnosis. As mentioned above, there are clear benefits to diagnosing and the treatment that can be offered for depression and other diagnoses. That said, diagnosis and the medical model can be confining: the label is for life, and thus the individual is put in a powerless position in regards to hope for progress or change, and instead is reliant on pharmaceutical treatment and psychotherapies that in some cases (e.g., [16]) do not take into consideration environmental factors that may be able to change and thus alter the person’s depressive state [20, 22]. According to Cipriani et al. [24], whilst there are reported benefits in cases where engagement and precise conformity to the antidepressant medication prescription are made by patients, there are also further arguments that medicating symptoms of depression can create a barrier for engaging in talking therapies, and concerningly report side effects of suicidality. Cipriani et al. [24] further postulate that SSRI antidepressants are prominent in these findings, and it could therefore be inferred that this research may put into disrepute any evidence for SSRIs being suitable or safe for use with BDNF for depression. In light of these findings, it could be advocated that a wider range of alternatives for understanding depression and the person’s lived experience of this, as well as the ‘why’ for this way of being-in-the-world are lacking, leading to a restrictive treatment protocol that leans towards a unilateral, individualistic medical-model approach.

In consideration of the symptoms that specifically relate to depression, there is a potential danger for traumatising and shaming when labelling the issue as inherent to a dysfunction within the person, and consequently adding to the existing suffering [25, 26]. To pharmaceutically medicate a person in this position further takes away the possibility of hope and capacity for positive change to occur through other means or reasons, particularly when evidence suggests that rates of pharmaceutical effectiveness are below 60%, and consequently the medication can be life-long [22]. In addition, if a person is on the severe spectrum of depressive symptoms, relying on their functionality in being able to consistently take medication may prove ineffective, as well as creating possible risk for suicidality [24]. In accordance with this appraisal, utilising the NICE [16] recommended cognitive talking therapies, which solely rely on cognitive function and consistent engagement for effectiveness, may also offer a paradoxical, non-desirable effect, particularly in cases where depressive symptoms are relating to environmental factors or another diagnosis such as trauma or PTSD [7]. It could therefore be reasoned that broader or alternative understanding for depression outside of internal neurological and cognitive dysfunction, and pharmaceutical intervention are needed in order to provide efficacious support that inhibits consistent positive change [27].

3. Biopsychosocial approaches

Whilst there are clear benefits to the medical model approach for depression and other presentations, research purports that a broader approach encompassing a person’s environment and wider social systems is needed (Table 2).

Medical model

Biopsychosocial model

Also known as the disease model. Non-Cartesian- body and mind separate It pathologises and uses a reductionist way of understanding the issue as being located within the person. E.g. Labelling and diagnosis. DSM5 It does not take into consideration other internal or external systems as being linked, e.g. systems such as environment, home, work, school, nature, social etc. The diagnosis does not change over time It conceptualises health as being present when disease is not- is therefore is not all encompassing of the human as an entirety within their environment, e.g. economic stress/ crisis causing heart attack/ anxiety, suicide It uses a medical treatment framework for issues, utilising CBT for depression for example, in a prescribed way. See NICE website. Anxiety/depression models: cognitive, diagnosis Therapeutic modalities that fall into this category: CBT, evidence-based models, e.g. EMDR using a prescribed number of sessions) Not uncommon to prescribe cognitive therapy & pharmaceutical intervention together

Engel, 1977 felt it necessary to widen the approach to dis-ease to include the psychosocial without sacrificing the huge advantages of the biomedical approach. Cartesian- body and mind as one The biopsychosocial model extends beyond medical-treatment and looks at the patient’s unique biological, psychological, social, co-morbidities, illness beliefs, coping strategies, fear, depression, employment, and financial concerns and may give further insight into what has hindered past recovery and sustained a position of dis-ease Additionally, the biopsychosocial model understands that pain/distress can be a dynamic entity that changes over time and is affected by a person’s internal and external environment Holistic framework, can use pathologizing and non-pathologizing language, diagnosis and other to understand a presentation Modalities that fall into this category: systemic, existential, humanistic. Could apply most models to this framework when used in a holistic way

Table 2.

Biopsychosocial and medical model approaches to understanding mental health.

Medical model [28]; Biopsychosocial model [18].

Engel’s [18] biopsychosocial model was created due to some of the limitations named above with the intention of keeping the elements that were beneficial in terms of the evidence-based approach. Overall, it sought to offer an extension of the medical model which took into consideration factors such as the mind and body being conjoined and not separate; viewing the person as being part of their wider societal, work, religion, education structure, and biological, neurological, physical, psychological systems being interrelated. As such, it is possible to start to understand depressive symptoms as being changeable or fluid within addressing potential systemic or environmental changes, both external and internal to the individual’s lived experience.

3.1 Evolutionary and animalistic concepts for depression

Darwin [29] proposes that as mammals we share six basic human emotions across the life span: anger, fear, jealousy, happiness, disgust, and sadness. It could be implied that any of these emotions can be present in someone who is experiencing depression when viewed from the biopsychosocial perspective, as it conceptualises health as being present when disease is not, consequently encompassing the human as an entirety within, and not separate to their environment. This ideology offers a view that as humans, our emotions, feelings and behaviours may be fluid and changeable and thus may also support the notion that ‘symptoms’ relating to depression are part of the human condition.

Neumann et al. [8] present an animalistic, evolutionary understanding that would make sense of depressive symptoms being a natural human response to factors such as economic stress or other crises that may further impact the person physically; for example, causing a heart attack; other symptoms such as anxiety; or in the worst case scenario, self-harm or suicide. As animals, and in particular, mammalians, our brain structure for processing emotions and responses to danger, stress or trauma, are extremely similar. The limbic brain, which is responsible for fight, flight, freeze, and the emotion centre, has been demonstrated through plentiful neuropsychological research to be similar for humans and animals; typically, in order of similarity: primates, horses, dogs, and cats, which is one of the reasons why animal assisted psychotherapies have a strong evidence base for efficacy for depression, and many other presentations [30]. It could therefore be understood, certainly on the most primal level, that responses to external, environmental factors are shared across mammalians with a limbic brain.

According to Darwin [29], some of the shared behaviours across the mammalian life span that can be likened to depressive ‘symptoms’ listed in Table 1, are: retreating to regroup, recharge, rest and mourn; as well as detaching interpersonally to recover from a physical or psychological event. Following this period of hibernation, animals then return to their social groups and integrate back into life. Other same and inter-species animals are accepting and non-judgemental of this, allowing time, understanding, social support and space for genuine and sustainable recovery. It could therefore be proposed that society and its systems; pathologising and its extension to lay-people, leads to a lack of understanding of depression being a fundamental part (and function) of the human condition [1]. Instead, precedence is given to neurological, biological and cognitive functions inside a person. The potential danger for an individualistic lens on depression is an inability for the individual and wider societal systems to allow recovery to take place: the option or choice to adaptively move in and out of depressive states is inherently taken away, and as such not accepted on a systemic level by others as being ‘normal’, thus leading to othering and shaming of the depressed person [25].

Other factors that disinhibit the above type of recovery or fluidity in regards to depression, are public and medical shaming and othering, leading to shared societal belief-systems that being productive and constantly functioning in all areas of life is normal [25]; that to rest and regroup or take time out is negative; thus the maintenance cycle for depression continues and worsens over time, particularly where people are ‘treatment-resistant’ to the recommended protocols (CBT and anti-depressants) [16, 31]. This may be what is being seen in the MRi scans in research pertaining to neuroplasticity and BDNF theories for people with depression where consistent changes in the cortex and hippocampus have been evidenced [14, 15]. Research is therefore needed to move towards a biopsychosocial framework of understanding where the psychological, cognitive, and neurological changes can be understood within a wider environmental context in order to inform and provide best-practice treatment protocols, as it seems that a core theme of becoming stuck, as it relates to depression, is emerging in the literature [32].

4. Understanding trauma in relation to depression: physiological and neurochemical factors from a biopsychosocial perspective

“When your physiology is stuck, you are stuck. Trauma can be defined as being stuck in protective reflexes” Haines [33].

Drawing on primitive, polyvagal and triune trauma models for the context of this paper, Van der Kolk [34, 35] and Porges [36] indicate that in order to endure highly stressful or traumatic events both psychologically and physically, our bodies have primal survival mechanisms that become activated. Part of our brain, the limbic system (also known as the reptilian brain and emotion centre), helps to keep us safe in the moment by triggering one of three primal responses: fight, flight and freeze. Fight and flight responses are known as mobilisation, which occur when the sympathetic nervous system is engaged and releases the chemical, adrenaline. Adrenaline allows us to fight for our lives or run from danger. In doing so, it turns off the digestive system, allowing blood flow to be channelled to vital organs (heart, lungs, limbs), which is often why people experience nausea during or after traumatic events, or do not know how they managed to run with a broken leg, for example. The freeze response is understood as immobilisation or dissociation, which engages the parasympathetic nervous system, encouraging collapse. It allows the body to shut down and preserve the body’s internal systems and passively avoid danger. All three of these responses allow us to be physically present during highly stressful or traumatic situations by removing awareness of thoughts, feelings, and sensations, either actively combatting the stressor (flight/flight/mobilisation), or shutting off from the stressor and passively avoiding it (freeze/immobilisation). As a side note, something that should also be considered in this physiological understanding of trauma, is a fourth response, known as social engagement. This response involves self-soothing and engaging with other humans through talking and accessing co-regulation of the nervous system, through sympathetic-adrenal influence, which is not always available in these situations. In effect it calms the system down, allowing the person to endure the stressor from a place of neutrality, as opposed to immobilising or mobilising.

4.1 Trauma and the environment

According to Mental Health Matters [37], understanding depression as being a fundamental part of the trauma model has been implied for the last century, as noted by key psychologists such as Freud [38]: hypothesis of sexual trauma and hysteria; and Bowlby’s [39] attachment theory. These earlier ideologies have been backed up by international frameworks such as Adverse Childhood Effects (ACE’s) [5], which offer decades of significant research to support the link between ACE’s and psychiatric conditions, including depression. In particular, Bowlby’s [39] attachment theory predicts that childhood neglect will create a trauma response throughout the human life-span. In support of this, evolutionary theories such as Eisenberger [40] depict that social connection is paramount for human survival. A varying range of biopsychosocial theorists and medical opinions are pointing to an understanding that depression is merely a part of being human; furthermore, that it is a typical and expected response to trauma and adversity; both in early childhood experiences as well as those endured in adulthood. In support of this, Porges [36] Polyvagal theory, proposes that as mammals, we experience life in one of three states: safe, mobilised, or immobilised (see Figure 1). In our optimum state of safety, we are regulated and open to social engagement, however, in response to perceived or extreme threat, we will move into a position of immobilisation (freeze/fawn/collapse) or mobilisation (fight/flight). Diseth [41] further offers neurobiological support of this theory that understands depression as a type of dissociative disorder in direct response to challenges within the environment, postulating that this primitive trauma feature enables a person to escape the present, lived-experience.

Figure 1.

Polyvagal theory: a model for understanding depression from a dorsal state [36].

4.2 Neurochemical responses to the environment

According to Van der Kolk [34], we have understood for over a century that a primal response to an individual or prolonged traumatic experience, is the release of neurochemicals in the brain for survival (see Figure 2). Specifically related to depressive symptoms, named in Table 1, is the opioid chemical release, which induces a lethargy response, allowing a mammal to freeze when in danger, and if this does not work, to later ‘flop’ or play dead [43]. Aside to being a fundamental process for trauma, the opioid system also plays a role in regulating mood. In their review, Jelen et al. [43] found that the opioid system is dysregulated when a person is experiencing depression, whether that be mild or severe, giving more credit to the notion that depression may be trauma related. Given that trauma symptoms are based on the physiology of being stuck [33], it is highly possible that depression could be understood through this analogy of being unable to recover from a freeze/opioid/depressed state. Additionally, from another perspective, it is widely reported that the endorphin release as it relates to all three of the trauma positions, and the relevant chemical release, is highly addictive [44]. It is often noticed within the psychotherapy platform, that clients with depression symptoms, not only appear to be stuck in a trauma position; but also seek to replicate and re-experience the feelings the endorphins initially provided. In conjunction, there is often a parallel goal of maintaining the position of stuck-ness, which can commonly be understood as the primary position of safety, thus representing a biopsychosocial and trauma perspective of depression.

Figure 2.

Trauma-induced imbalance of neurological chemicals [42].

4.3 Trauma or depression?

Gawęda et al. [45] explored the relationship between suicidality, depression, childhood trauma and other factors. They found a strong correlation between trauma and depression, adding weight to the hypothesis that depression may be a set of symptoms experienced following trauma, particularly when a person is stuck on the trauma loop cycle [33]. In more severe cases, being locked in a depressed state and unable to move fluidly out of it, suggests that there may be a trauma-related neurochemical imbalance, as well as a physiological freeze in the system. Alongside the physicality of experiencing depression, clients will often describe living life with the handbrake continuously on. Additionally, within this lived experience, it is commonly reported that there is struggle with motivation and procrastination cycles, as well as feeling ‘foggy’ in relation to cognition. Jelen et al. [43] postulate that the opioid system is further responsible for reward and well-being, and thus poses the question as to whether this aspect can be accessed when in an immobile trauma state, or whether in fact the opioid release is the reward. In support of this, Remes et al. [46] conclude from their biopsychosocial research on depression that ‘functional dissociation’ occurring on a cerebral level can be accountable for both the low mood and anxious states reported as symptoms (e.g., Ref. [4]) for this presentation, once again supporting the overlap between trauma and depression.

To conclude our understanding on physiological and neurochemical factors relating to depression, the research strongly supports the notion that there is a direct link between causation for depression, and maintenance of depression through a trauma lens [5, 45]. Furthermore, from a wider biopsychosocial perspective it can be argued that outside of the initial traumatic event(s), the primal immobile trauma response allows a person to maintain a position, or range of symptoms, relating to depression (see Table 1) where disengaging and escaping from life and coping with difficulties or adversities, can be achieved through a numbing mechanism gained from the opioid system [43, 44, 46]. As a final point, from an interpersonal perspective, given Eisenberger [40] denotes that we require social connection for human survival, and that the freeze response will isolate the person and negate possibilities for this to happen, it could also be proposed that being stuck in the immobile state of inaction alone could lead to ongoing, severe symptoms of depression, suicidality and death due to the inability of being able to physically or otherwise connect to others.

4.4 Physiological impact from stress and trauma as it pertains to depression

Historical and ongoing research has maintained a consistently strong curiosity and acknowledgement, certainly more recently, on the understanding and complexities that stress has on the mind and body [47]. For decades, studies have set out to understand what the acronym ‘MUS’ represents and means. Hashimoto et al. [48] investigated ‘MUS’ in relation to fatigue; a common symptom in depression, and shared among a broad range of other diagnoses. ‘Medically Unexplained Symptoms’, is a term that practitioners use within the medical healthcare systems, when a patient does not fit any category for diagnoses. Generally speaking, the research has turned a table in the last decade, with a move away from the ‘MUS’ umbrella category, to the ‘Stress’ category, in an attempt to account for ‘unexplained’ symptoms.

Remes et al. [46] postulate that depression is linked to the hypothalamic-pituitary-adrenal axis (HPA axis). The HPA axis forms part of the neuroendocrine system, and its main function is to respond to stress. In addition, it also regulates other systems such as the digestive, emotion, and immune, in response to environmental cues. Its link to depression is framed in conjunction with HPA axis dysregulation caused by stress, purporting a direct link between the environment being a causative factor for depression. This can be further understood by its links to ACE [5] which create a predisposition towards maladaptive coping strategies to highly stressful or traumatic experiences. In particular, it is posited that early attachment wounds are predictors for mood disorders, for which category depression falls into.

Porges [36] vast research on Polyvagal theory has provided a strong compass for understanding depression as being part of the human condition. In line with Eisenberger [40], the polyvagal theory suggests that our need for connection in a life threatening experience is dependent on it as one of the main trauma responses (fight, flight, freeze, and social engagement). When available, social engagement can regulate the parasympathetic nervous system (PNS) through sympathetic-adrenal influence, allowing the person to endure the stressor from a place of neutrality, as opposed to immobilising or mobilising. The vagus nerve is responsible for controlling the PNS, which aims to regulate the body at rest. When vagal tone is high, resilience to stress is also heightened, and the body can maintain homeostasis. There has been a marked correlation between high vagal tone producing a positive feedback cycle, which promotes positive emotions. In contrast, low vagal tone leads to a negative feedback cycle, supporting the relevance of polyvagal theory in understanding depression.

Consistent with this view, when stressful environmental factors are present, and social co-regulation cannot be sought, an immobile, freeze position is often assumed and maintained, emphasising the very need for human connection [40]. Given the criteria for a diagnosis of depression are inclusive of social withdrawal and isolation (Table 1), it starts to imply that early childhood attachment wounds [39], and sexual trauma [38] are unequivocal explanations for depression being a safety behaviour to escape from human connection, which has previously been unsafe to access in early childhood years. This accounts for the maintenance cycle and other medical healthcare interventions that are ineffective, and offers a credible understanding for depression.

5. Recovery for depression in a natural world: psychotherapies supporting the biopsychosocial and trauma-informed models

5.1 The importance of addressing the body when working with depression

‘We have evolved to move away from using our bodies as sensing tools in regards to primal safety, non-verbal communication [and] illness’ ([49], p. 128).

It can be argued that being stuck in a trauma-response cycle will lead to significant dissociation from the body, as a natural response to perceived or actual threat, in order to endure physical or psychological pain [36]. In considering the body of research discussed above, which highlights the possibility of depression either being part of, or caused by trauma; or a response to navigating highly stressful or adverse environmental triggers, it is highly likely that disconnect from the body remains fairly consistent when experiencing depression [26].

When we experience highly stressful or traumatic situations, part of the brain called Broca’s area (see Figure 3), responsible for retrieving verbal memory, shuts down [50]. Consequently, when considering effective interventions for addressing the symptoms of depression, this poses a barrier for talking therapies. In my experience, when clients are experiencing severe distress in a room-based psychotherapy setting, relying on interventions such as Beck’s [17] CBT, can lead to clients freezing and being unable to speak. At that moment, they report being blank, and figuratively speaking, it becomes clear that Broca’s area, responsible for retrieving verbal memory, is not functioning typically. In those situations, using interventions that solely rely on cognitive processing can pose ethical challenges, risking the potential for pathologising and shaming to occur, as well as the possibility for the therapist becoming de-skilled, presenting further risk for harm [26, 49]. When Broca’s area is de-activated, neurobiological research has demonstrated clear association with other limbic areas that are responsible for traumatic dissociation [41], posing another risk for both the client and therapist’s safety, as the client could very easily move from an immobile into a mobile state of flight or fight [34].

Figure 3.

The location of Broca’s area in the brain: responsible for retrieving verbal memory [50].

In hypothesising that depression could be linked to, or a cause of trauma, another important factor to be aware of when delivering psychotherapy, would be a client’s tendency to dissociate and slip into a helpless, opioid state, whereby we can no longer reach them, and they cannot hear us [46]. In my clinical experience, this phenomenon happens often with clients that have experienced trauma, and have a tendency to lean towards a depressive lived experience, relying on strategies such as food to induce and maintain an opioid state of being numb and immobile. This is crucial from a point of safety whereby something may be mentioned or triggered in a session that leads to the client freezing. In that moment, it is not effective or appropriate to rely on interventions that necessitate a cognitive action; and the moment to moment, lived experienced of the client must be attended to on a physiological level [34, 35, 50].

5.2 Addressing the physiology in psychotherapy sessions

Van der Kolk [50] and Porges [36] propose an alternative model for situations which necessitate a ‘bottom-up’ somatic process, as opposed to a ‘top-down’ cognitive methodology. The crux of these somatic models lays within consideration of the primal responses we function from when our physiology is stuck [33], and as such, offering interventions that enable us to address the dissociation and dysregulation of the client’s nervous system (see Figure 4). Secondly, Porges [36] Polyvagal theory holds salience for embodied, regulated social support when seeking relief from being in one of the three trauma states. Somatic psychotherapy necessitates that practitioners hold a high level of self-awareness in being able to regulate and ground themselves first and foremost, so that they may physically and physiologically hold space for their client. Training in somatic psychotherapies enables this skill, along with interventions such as mindfulness and noticing moment to moment what is happening in both the therapist’s and client’s body, as opposed to focusing on the words. Noticing the speed at which the client is talking, and encouraging pausing and awareness of the internal and physical experience, offers a bridge back to forming a body-mind connection. Regulating the client’s nervous system during sessions has a long-term effect of offering a feeling of safety for them within their bodies, which for some clients is so revolutionary, that they often recall not having ever experienced this. Once this safety can be achieved within the body on a physiological level, cognitive functioning improves, and safety can be sought and maintained through interpersonal relationships. Given the biopsychosocial and evolutionary understandings of depression, and the salience for human-connection in order to survive [40] this methodology presents as vastly important in offering the grounding for addressing the basics of being-human, and essentially, offering a new possibility for clients in being able to move fluidly in and out of the necessary depressive states for survival. It removes the likelihood for potential shaming and re-traumatisation within sessions, offering a secure-base of safety, not only intrapersonally, but interpersonally too, within the confines of the therapeutic relationship as is a much researched, necessary condition for any psychotherapy to work [52, 53].

Figure 4.

The limbic brain: responsible for fight, flight, freeze, and the emotion Centre [51].

5.3 Tension and trauma release exercises (TRE)® for depression

In the 1980’s David Berceli [54] created a body work model for a range of natural human responses to stress and trauma that typical talking therapies were falling short in supporting. It was initially designed for use in war and natural disaster zones, but over the years, it has been adapted for use in a wide range of settings. There is a plethora of research that supports the understanding that trauma is not only a psychological experience, but conjoined with, and stored within the body [34, 35, 50]. Consequently, it is vital that people can safely connect to the body and start to process the stored trauma.

Berceli’s [54] TRE® is a set of seven exercises that assist the body in releasing deep muscular patterns of stress, tension and trauma that are held in the body. The exercises safely activate a natural reflex mechanism of shaking or vibrating that releases muscular tension, calming down the nervous system. When this muscular shaking/vibrating mechanism is activated in a safe and controlled environment, the body is encouraged to return back to a state of balance.

5.4 The importance of tremoring for general health, emotion regulation and depression

According to Berceli [55], Tremors occur naturally, as a primitive response to highly stressful and traumatic events across the mammalian lifespan, however, due to social and medical trends that pathologise tremoring, humans have largely turned off this processing strategy. Tremors help to relax the muscle tissue and release chronic tension. A fundamental phenomenon which has arisen out of tremor research, is that the tremors can connect the historical and current cognitive aspects (memories and thoughts) to the tremor experience, thus connecting body and mind, and bringing awareness into the embodied present.

Once a person has experienced trauma, they can become fixed and reliant on primitive defence reflexes [33], meaning that environmental information feeds straight into the nervous system and into the limbic brain, inhibiting a fight, flight, or freeze response to all stimuli. In line with Van der Kolk [35]; Berceli [54], postulates that tremoring can help to change emotions, cognitive thoughts, and dialogue that have become immovable, by interrupting the trauma loop. Tremoring helps to interrupt this by breaking the cycle, and beginning to send information into the rational thinking part of the brain (the cortex). Additionally, inducing tremors often can regulate all systems of a person’s body, and keep it fairly free from tension, which in turn promotes general well-being. This approach is supportive of what Beck’s [17] model of cognitive therapy is seemingly trying to achieve: a prevention for rumination, and changing thinking patterns, in order to alter the feelings and behavioural state. The major difference for TRE® is that this can be achieved in a non-intrusive or shaming way; supporting an inclusive, non-verbal approach, where Broca’s area may have shut down, or individual clients are unable to speak or articulate their experiences to inhibit necessary change. It promotes safety and regulation for clients in a gentle, person centred way, where talking therapy is not available or appropriate. Furthermore, it is taught as a self-help tool, thus offering longevity and social inclusion, where other long-term therapies may have high-cost or engagement implications. It also lends itself to both group classes where co-regulation and social connection is sought, as well as the availability for individual sessions.

5.5 Equine and canine assisted psychotherapies for depression

‘Dogs are wise. They crawl away into a quiet corner and lick their wounds and do not rejoin the world until they are whole once more’ [56]. Christie and Suchet’s [56] observation of dogs, speaks to the biopsychosocial concept mentioned above, in attempting to understand why human social systems dictate norms such as consistent, robotic functioning, whilst denigrating rest or illness as weakness [25].

Given the many similarities humans share with mammals, in particular: primates, equines, and canines, (listed in order of most similar limbic brain), it is not unusual to consider the benefits of connecting with them on a non-verbal level for therapeutic reasons [26]. There are a number of shared social, biological and neurological processes across mammalian species, and not least important of all are the capacities to deal with life threatening scenarios, exhibiting our primal trauma responses [29, 36]. Notably, processes for social attachment and regulation are also very similar, and hence the limbic part of the brain (responsible for fight, flight, freeze, fawn and social engagement) in canines and equines are very similar to humans [57]. With that in mind, we can start to understand a salient basis for recovery from depression. Primarily, animals are fluid and able to move in and out of the depressive state, provided their habitats allow that adaptability, and thus offering a secure-base and modelling for healthy attachment and trauma templates [58].

Based on the literature already presented in this paper, it is postulated that depression is part of the mammalian condition [8, 29]. This therefore offers a non-verbal platform to connect to dogs or horses within a therapy setting (see Figure 5). The research has strongly indicated that depression has strong correlations with the human need for connection [36, 45], yet, when stuck in an immobile or opioid state, achieving connection, which Eisenberger [40] argues is vital for survival, is not possible. This suggests that alternative therapeutic interventions that will encourage engagement are needed.

Figure 5.

A canine assisted psychotherapeutic interaction demonstrating limbic resonance.

In understanding depression as being a response to, or part of trauma [45]; Van der Kolk [34], offers a neurobiological viewpoint that in order to move a person from trauma to healing requires neural pathways to be restructured, encompassing processes such as neurochemical rebalance, and finding safety through connection [36]. In support of this, literature suggests that neural rewiring can only happen when the individual experiences new responses and activities which soothe and regulate the limbic brain [26]. In conjunction, Lewis et al. [59], propose three stages that will lead to the neurological re-wiring for mammals: (1) limbic resonance, which is where two mammals attune to their internal states whilst sharing empathy; (2) limbic regulation, where two mammals can adapt, soothe and regulate one another’s physiology through reading non-verbal emotional cues; and (3) limbic revision, whereby the adaptation over time creates a healthy, or typical template for achieving authentic connection. Based on research such as Foley [58], it can be put forward that AAT would be highly suitable as a biopsychosocial intervention for both trauma and depression (see Figure 6).

Figure 6.

Benefits of animal assisted psychotherapies [58].

Animals are fantastic at offering non-verbal reflections of what is happening for us in the moment [60]. They are highly-sensitively attuned to our emotional states, creating another platform for increasing self-awareness and interrupting the immobile states that depression can create [46]. Whilst doing so, they are able to gently interrupt moments of overwhelming emotion and bring awareness back into the moment. This offers a safe space for new patterns of emotion regulation to develop, tools to utilise outside of sessions, and consequently to stop feeling saturated by the overwhelm emotions can sometimes bring [26].

According to Foley [58], animals also bring their own personality and character into the sessions offering space for reflection, companionship, and healing. Sometimes too, they bring laughter and joy, and offer an opportunity for building a relationship that encompasses a person’s most vulnerable self. This encourages acceptance of self, and self-compassion to our most vulnerable parts, promoting a model for a fluid position in framing and moving in and out of a depressive state whilst navigating a healthier template for connection (Figure 7) [8].

Figure 7.

Benefits of equine facilitated psychotherapy [26].

In consideration of the hypothesis for trauma-based neurochemical aetiology for depression, Morrison [61], documents a plethora of health benefits for animal assisted psychotherapies (AAP). Markedly, in view of the literature supporting a correlation between stress and depression, it is widely reported that AAP lowers the stress hormone, cortisol. Corresponding to this heart and breathing rate are also lowered, offering another solution aside to somatic psychotherapy in attending to the physiological aspects, that depression, as a result of trauma, requires [34, 36, 50]. Overall, AAT offers an advantage over other psychotherapies, in particular, due to the non-verbal attachment re-wiring that can take place at the neurological level (e.g., Refs. [34, 59, 60]). Additionally, it is purported that engagement rates are higher than in clinical settings, due to the removal of stigma, and the motivational offering of joy, hanging out with animals can bring. Challenges in accessing AAT may be due to fear or allergy, or a negative past experience, and all except the allergies, may be addressed and included as part of the therapeutic plan [62].

5.6 Nature assisted psychotherapy for depression

The medical model literature for depression and treatment protocols seems to mimic a parallel process for what people with depression are experiencing in their waking lives; a negative feedback loop, encompassing a maintenance cycle of remaining stuck [12, 46]. Biopsychosocial research for depression offers alternative ways to understand and help, and in doing so, possibilities for embracing our human-ness for fluidly being able to adaptively move in and out of depressive states without getting stuck [8, 20]. Encompassing the latter into a therapeutic intervention authentically, could bring about the necessary connection and change needed to recover when an impasse is reached.

Nature assisted psychotherapy (NP) is described in Williams [49] p. 130 as ‘offering a congruent, non-judgemental space for people to recover’. In considering depression as part of the human condition from one of the biopsychosocial perspectives, NP can provide a social constructionist epistemological approach, in understanding that humans are part of nature and its biological systems, and do not exist separately to this. NP resembles much of the humanistic approach to psychotherapy that Rogers [52] understood as fundamental aspects for why a person seeks therapy. Namely, he postulates that we seek therapy when we are in a state of incongruence, which creates an internal conflict causing distress for how we are experiencing life; in other words, causing an imbalance within our lived-experience of the system. Porges [57]; Eisenberger [40]; and Darwin [29] argue that to remain in a state of balance and regulation, it is necessary to maintain healthy social connection. It could further be recognised that these theorists understand human existence from a systemic lens: that we do not exist as separate to others, we are connected intrapersonally to our various bodily systems; our mind is not separate to our body, our physiology not separate to our biology; and we also exist as part of our wider familial, work, school and other social systems. In line with the latter social constructivist worldview, it is also assumed that we are interconnected to nature and its biological and ecological systems. As such, NP offers the opportunity to explore these inter-related connections, and in doing so the relationship we have with ourselves and our environment, making it a good fit for those experiencing depression (see Figure 8). From a trauma-informed perspective, it could be argued that the embodied safety that can be achieved through NP, could allow us to extend this safety in connecting with others: a fundamental aspect for being able to move out of depressive states [35, 57].

Figure 8.

The benefits of nature assisted psychotherapy [49].

Aside to the physical and psychological health benefits listed in Figure 8. NP also offers the flexibility to integrate other types of psychotherapy into the practice in order to provide a bespoke and individual approach to each person [49]. This humanistic way of approaching client work leaves less room for pathologising, shaming or othering the client [25]. In addition to the broad applications of NP and its appeal to those who may find traditional, clinical settings too stigmatising; NP can also be disseminated in a range of socio-economic and diverse levels, ranging from the psychotherapy room, to community projects, offering an extensive platform for accessibility. Within the process of physically connecting to nature, whether that be through walking or hugging a tree, Van der Kolk’s [34] guidance for re-establishing a body-mind connection, can easily be achieved through various grounding exercises, and consequently, offers a solution for connecting to, and processing emotions and trauma that are stored, and or stuck, in the body. Nature further offers a variety of non-verbal exercises that encapsulate an embodied and connected experience. This characteristic presents another way in which practitioners can attend to the client’s physiology, and begin the process of regulation and stabilisation; absolutely crucial for clients that are suicidal, or self-harming in any way [63]. NP offers a suitable, flexible, and affordable intervention within a wide range of settings for clients with depression [49]. That said, the ethical and safety implications for working psychotherapeutically in nature should be carefully considered.

6. Conclusion: can we recover from depression?

What exactly does it mean to recover? In line with Hathcoat et al. [64], this question may be addressed and framed depending on the epistemological position and viewpoint for how depression is understood. Importantly, it is the ontological and epistemological positions we take that determine the societal and individual outcomes for health related issues. As previously outlined above, in an individualistic epistemological framework, the medical model understands depression as being a defect within the person, generally negating other biological, environmental or social factors (e.g., [20]). Within this ideology, the person holds a limited and hopeless outlook, and is solely reliant on healthcare systems to ‘treat’ or change the symptomatology of their internal dis-ease [7]. When conceptualised in this way, research suggests that treatment aligning with the medical model overall is ineffective, thus resulting in an understanding that depression is incurable and a debilitating, life-long illness [12].

It has been proposed that the biopsychosocial viewpoint is an epistemology in its own right [65] however, it would also fit with a social constructivist (sociological theory depicting interactions with others); social constructionist (biological and natural, depicting shared understandings of the world); and humanistic (emphasis on individual and social potential as well as human agency) positions [66]. Within this framework, depression is understood as not only being part of the human condition, normalising symptoms and creating the possibility of fluidity in relation; but in conjunction, offers the option for recovery, since its understanding is, that depression is a temporary state that we can move in and out of in conjunction to the wider systems we are part of [8, 36].

On reflection of the research presented in this paper, it can be agreed between both the medical and biopsychosocial model perspectives, that ACE’s, attachment wounds, and trauma, predispose a person to experiencing severe depression across the life-span [5, 46, 67]. With that in mind, the causative factors can be understood as being external and environmental, and something that happened to them, as opposed to by them, or solely inside them [8]. Importantly, this purports that psychotherapeutic interventions should include a trauma-informed approach, directed by more than a set of symptoms for depression, which could further be argued, are a set of symptoms for trauma [32, 34, 45, 57, 68]. Future research should explore trauma-informed therapeutic interventions for depression, with a hope to informing policy change for national healthcare systems, that are still reliant on the limited efficacy pharmaceutical and cognitive therapy interventions bring [27, 69].

Conflict of interest

It could be considered a conflict of interest that the author works within nature, canine and animal assisted therapy settings, as well as being a certified TRE® practitioner, with an emphasis on somatic processes within clinical work. Consequently, there may be some bias expressed in the writing.

Notes

None.