Serotonin, mood and violence.

Serotonin (5 hydroxy tryptamine) is a derivative of the amino acid tryptophan. It is present in high concentration in certain areas of brain called median and dorsal raphe nucleus. From the neurons in this area fibers project diffusely to all the major brain areas. Serotonin is implicated in sleep, regulation of mood, appetite and sexual behavior.
Low levels of serotonin are found in victims who die of suicide. Still lower levels are found in the brains of victims who choose more violent methods to kill themselves. Low level is linked to propensity to show violent behaviors.
Reduced serotonin transmission is implicated in anxiety disorders, depression and the negative symptoms of schizophrenia.