Serotonin metabolism is disordered in a variety of clinical states. These include addictions, attention deficit disorder, chronic pain, depression, dysthymia, eating disorders, headache, obsessive-compulsive disorders, panic, poor impulse control, post-traumatic stress disorders, premenstrual syndrome, sleep disorders, stress disorders, sudden cardiac death and violence. A decreased serotonin state has also been implicated in sleep disorders which then progress into dysthymia and depression. Serotonin can be altered by a variety of means, including acupuncture, body work, cranial electrical stimulation, diet, electromagnetic fieIds, exercise, light, sound, and the highly effective Serotonin Selective Reuptake Inhibitors (SSRI). An individual's genetically determined stable set point for serotonin may be disordered by environmentally induced events, leading to altered sleep, dysthymia and depression. This imbalanced neurochemistry cascades into an autommic nervous system hyperactivity causing symptoms. The neurochemical biophysiological basis of much mental as well as much multi-factorial illness in becoming clearer. It is hypothesized that potentially treatable low serotonin states are the final common pathway in many medical disorders.