Year: 1993 Source: Suicide and Life-Threatening Behavior, v.23, no.1, (Spring 1993), p.74-75 SIEC No: 19930247

The hypothesis that a peaking of suicide deaths in males during the morning hours may be due to diurnal variation of serotonin & decreasing serotonergic-mediated inhibition of dopamine is discussed in this letter. Supporting evidence includes: a link between low serum cholesterol & suicide; importance of dopamine in the control of wakefulness manifested by a reduced reaction time & gap frequency; & the fact that delay-dependent speeding of reaction time is abolished by depletion of dopamine.