The Role of Serotonin in Aggression and Impulsiveness

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