The 220 cases (Table 1) included 82 people who had committed suicide and 138 nonsuicide controls. Subjects were divided clinically as follows: a definite lifetime history of major depressive episode either bipolar or unipolar (n = 53), definitely no lifetime history of a major depressive episode (n = 107), and indeterminate (n = 60); a definite history of alcoholism or substance abuse (n = 86), definitely no history of alcoholism or substance abuse (n = 83), and indeterminate (n = 51); and a definite history of pathological aggression (n = 38), a definite history of no pathological aggression (n = 92), and indeterminate (n = 90). All indeterminate individuals were omitted from the applicable analyses. Other major diagnoses included schizophrenia (27%), schizophreniform reaction or schizoaffective disorder (12%), dysthymia (1%), and bipolar disorder (2%). All subjects had toxicologic screening of blood, urine, and bile and a clinical history. Most subjects had brain toxicologic screening for selected psychotropic drugs and alcohol (28% had positive brain screen results in the face of negative results of peripheral body fluid screening) to ensure drug-free status. Drugs screened for included benzodiazepines, tricyclics, antipsychotics, most drugs of abuse, lithium, trazodone hydrochloride, bupropion hydrochloride, selective serotonin reuptake inhibitors, amphetamine sulfate, caffeine, and alcohol. Other than drugs for medical conditions, results were as follows: positive screening results included benzodiazepines (n = 6), cocaine/benzoylecognine (n = 10), opiates (n = 14), carbon monoxide (n = 11), antipsychotics (n = 2), caffeine (n = 3), antidepressants (n = 6), lithium (n = 3), barbiturates (n = 2), cannabis (n = 5), and antihistamines (n = 5). Some cases had more than 1 positive drug test result, and any cases with monoaminergic-related drugs did not have 5-HTT binding assayed. Subjects with evidence of a neurologic disorder on history or at autopsy were excluded.