Background and purpose: Substance use disorder is one of the important mental health problems related to suicide, nearly equal with depressive disorder. However, it is unclear how differences of abused substances influence the suicide risk of individuals with substance use disorder in Japan. The purpose of the present study is to compare an estimated suicide risk among patients with alcohol, amphetamine, and sedative, hypnotic or anxiolytic use disorders.
Methods: Subjects were 1082 outpatients with alcohol use disorder (AUD), 191 with amphetamine-like use disorder (AMUD), and 63 with sedative, hypnotic or anxiolytic use disorder (SUD), all of whom consecutively had consulted seven medical facilities specialized for treatment of substance use disorder during a month of December 2009. A self-reporting questionnaire including the items of Kessler 10 (K10) and the Mini International Neuropsychiatric Interview (M.I.N.I.) was administered, and scores of the K10 and M.I.N.I., and the other clinical information were compared among the patients with AUD, AMUD, and SUD.
Results: Patients with AMUD and SUD showed significantly higher score on the M.I.N.I. than those with AUD, while those with SUD showed highest score on the K10, followed by those with AMUD. In either of patients with AUD, AMUD, or SUD, approximately 60% of the subjects who attempted suicide within a month reported to take any psychoactive substance in the attempted suicide. Additionally, a remarkable difference was found in histories of general psychiatric treatment before consulting medical facilities specialized for treatment of substance use disorder between these three groups. Most of outpatients with SUD reported such histories.
Conclusions: Outpatients with SUD appeared to involve the highest risk for suicide of all patients with substance use disorder, probably because of the comorbid-severe depression. In our speculation, SUD which our subjects suffered from might be induced or accelerated by pharmacotherapy performed in general psychiatric facilities. Education on dependency of prescribed psychotropic drugs to general psychiatrists is required.