Examining heterogeneity in the affect-regulating function of suicidal ideation: Person-specific analyses in male inpatients with depression.

Introduction: Men have an increased risk to die by suicide compared to women but are underrepresented in suicide research. To improve individual risk prediction for suicide-related thoughts and behaviors (STBs), risk factors are increasingly being studied at an individual level. The possible affect-regulatory function of suicidal ideation has hardly been investigated ideographically and has not yet been tested in a male sample.

Methods: We investigated the bidirectional associations between suicidal ideation and negative and positive affect in a sample of n = 21 male inpatients with unipolar depression and a history of suicidal ideation both at the group level and at the individual level. Participants underwent an intensive ecological momentary assessment for 6 days with 10 data points per day.

Results: We found no evidence for an affect-regulatory function of suicidal ideation at the group level, neither for effects of affect on subsequent suicidal ideation (antecedent affect-regulatory hypothesis) nor for effects of suicidal ideation on subsequent affect (consequence affect-regulatory hypothesis). Person-specific analyses revealed substantial variability in strength and direction of the considered associations, especially for the associations representing the antecedent hypothesis.

Conclusion: The demonstrated between-person heterogeneity points to the necessity to individualize the investigation of risk factors to enhance prediction and prevention of STBs.