Insomnia Symptom, Mental Disorder and Suicide: A Case-Control Study in Chinese Rural Youths.

Insomnia has been reported as a risk factor of suicidal behaviors, but few studies have examined the association among insomnia, mental disorder and suicide, especially among Chinese populations. In this study, we examined the effect of insomnia symptoms on completed suicide in a large sample of suicides and their controls in Chinese rural youths. Subjects were 388 consecutively recruited suicides and 416 community living controls aged 15-34 years in the rural areas of three provinces in China. Established psychological autopsy method was used for the data collection. Insomnia symptoms were assessed with sleep questions in the Hamilton Depression Rating Scale (HAMD) about insomnia, including difficulty initiating sleep (DIS), difficulty maintaining sleep (DMS) and early morning awakening (EMA). The results showed that DIS (OR=12.01, p<0.001), DMS (OR=12.82, p<0.001) or EMA (OR=12.08, p<0.001) was significantly associated with increased risk of suicide even after mental disorder was controlled for. Our study showed that insomnia can be an independent risk factor for suicide. Mental disorders mediated the association between insomnia and suicide. Insomnia should be assessed and treated for individuals at risk of suicide.