Objective: Studies from three independent laboratories report varying relationships between electrodermal hyporeactivity and suicidal behavior in depressed patients. The aims of this study were to explain that variation, to assess the discriminative validity of electrodermal hyporeactivity for suicide and suicide attempts and to suggest a tentative explanation model.
Method: A meta-analysis was performed of 279 depressed patients and 59 healthy subjects.
Results: The sensitivity was 96.6% and specificity 92.9% of electrodermal hyporeactivity for suicide and 83.3% and 92.7%, respectively, for suicide and/or violent attempts. The shares of hyporeactives were strongly significantly and greatly larger in high than in low suicidal propensity groups, P-value ranging from 4.7 × 10−8 to 1.1 × 10−14.
Conclusion: The high discriminative validity and the emerging links over a proposed interest-limiting precognitive set to cognitive theory of suicide encourage clinical application of tests of electrodermal reactivity. The study offers a series of testable hypotheses constituting a new platform for suicidological research in depression.