Serotonin is a neuromodulator that has a critical role on the regulation of essential events in neuronal and glial development, such as cell proliferation, differentiation, migration, apoptosis, and synaptogenesis, and acts as a developmental signal. It has been known that a serotonergic system is associated with many psychiatric disorders. The serotonergic system also predominates on the etiopathogenesis of two important endophenotypes: impulsivity and aggression. Impulsiveness is defined as personality trait and an implusive temperament is associated with clinical conditions such as pathological gambling, eating disorders, and borderline personality disorder as well as being a risk factor for self‐harm, suicide, and emotional liability. Aggression is not a personality trait like impulsivity, but it is the behavior of harm or injury to others. Besides being a natural human behavior toward survival, aggression can be harmful to the individual and the community when it is constant and excessive. In this chapter, we aimed to review the role of the serotonergic system on impulsivity and aggression, which are two important endophenotypes that identified in many psychiatric disorders.
Part of the book: Serotonin
The main aim of this section is to provide clinicians with a guide to the prevalence of psychopathologies, associated factors, and their treatment in children with Down syndrome (DS). Attention-deficit/hyperactivity disorder (ADHD), behavioral disorders, depression, and autism are more common in DS than the normal population. However, the incidence of psychopathology is generally lower in DS than in other diseases that cause mental retardation. While writing this chapter, approximately 200 articles in electronic databases were scanned using the keywords “Down Syndrome and Psychopathology,” “Down Syndrome and Mood Disorder,” “Down Syndrome and Autism,” “Down Syndrome and Anxiety,” “Down Syndrome and Catatonia,” and “Down Syndrome and Behavioral Disorder.” Psychopathologies in DS will be presented in eight subtitles beginning with the most often diagnosed. It is important to perform psychological evaluations of patients with DS during routine follow-ups. Comorbid diseases (obstructive sleep apnea, cardiac pathologies, etc.) should be taken into account when choosing drugs.
Part of the book: Advances in Research on Down Syndrome