Insight into mental disorders and suicidal behavior: a qualitative and quantitative multimodal investigation

To investigate the association between insight into mental disorders and suicidal behavior.

English and French MEDLINE databases up to January 2014 were searched using suicide combined with awareness, consciousness, insight and anosognosia, unawareness, and awareness of illness. We also conducted a cross-sectional study comparing Mood Disorder Insight Scale (MDIS) and 24-item Hamilton Depression Rating Scale (HDRS-24), item 17, performance between 22 depressed (DSM-IV-TR criteria) suicide attempters and 22 patient controls.

Study selection was based on the STROBE checklist. Selected studies were published in an English- or French-language peer-reviewed journal, included at least 1 measure of insight, and included patients with a history of suicidal behavior. Thirty-two studies were reviewed, of which 12 were longitudinal.

A review of the literature and meta-analysis of studies were conducted to compare insight in patients with versus those without a history of suicidal behavior.

Most studies (25) were conducted in psychotic disorders. A small majority showed a positive association between 1 measure of insight and higher risk of suicidal ideas or acts in both psychotic and mood disorders. Our study found that suicide attempters, mostly female attempters, tended to have better insight into depression than patient controls according to the HDRS-24 (P = .06, effect size = 1.43 [95% CI, 0.77 to 2.09]) but not MDIS. Finally, a meta-analysis of 7 studies confirmed significantly better insight scores in suicide attempters, with a small effect size (Hedges g = -0.16 [95% CI, -0.3 to -0.03]).

Overall, a significant but weak association was found between insight and the risk of suicidal behavior. We also raised methodological and conceptual concerns and discussed new measures (eg, test based).