Childhood cognitive ability and self-harm and suicide in later life

Matthew H Iveson; Emily L Ball; Heather C Whalley; Ian J Deary; Simon R Cox; G David Batty; Ann John; Andrew M McIntosh

doi:10.1016/j.ssmph.2023.101592

Childhood cognitive ability and self-harm and suicide in later life

SSM Popul Health. 2023 Dec 29:25:101592. doi: 10.1016/j.ssmph.2023.101592. eCollection 2024 Mar.

Authors

Matthew H Iveson¹, Emily L Ball¹, Heather C Whalley¹, Ian J Deary², Simon R Cox², G David Batty³, Ann John⁴, Andrew M McIntosh¹

Affiliations

¹ Centre for Clinical Brain Sciences, The University of Edinburgh, UK.
² Department of Psychology, The University of Edinburgh, UK.
³ Institute of Epidemiology and Health, University College London, London, UK.
⁴ Swansea University Medical School, Swansea University, Swansea, UK.

Abstract

Background: Self-harm and suicide remain prevalent in later life. For younger adults, higher early-life cognitive ability appears to predict lower self-harm and suicide risk. Comparatively little is known about these associations among middle-aged and older adults.

Methods: This study examined the association between childhood (age 11) cognitive ability and self-harm and suicide risk among a Scotland-wide cohort (N = 53037), using hospital admission and mortality records to follow individuals from age 34 to 85. Multistate models examined the association between childhood cognitive ability and transitions between unaffected, self-harm, and then suicide or non-suicide death.

Results: After adjusting for childhood and adulthood socioeconomic conditions, higher childhood cognitive ability was significantly associated with reduced risk of self-harm among both males (451 events; HR = 0.90, 95% CI [0.82, 0.99]) and females (516 events; HR = 0.89, 95% CI [0.81, 0.98]). Childhood cognitive ability was not significantly associated with suicide risk among those with (Male: 16 events, HR = 1.05, 95% CI [0.61, 1.80]; Female: 13 events, HR = 1.08, 95% CI [0.55, 2.15]) or without self-harm events (Male: 118 events, HR = 1.17, 95% CI [0.84, 1.63]; Female: 31 events, HR = 1.30, 95% CI [0.70, 2.41]).

Limitations: The study only includes self-harm events that result in a hospital admission and does not account for self-harm prior to follow-up.

Conclusions: This extends work on cognitive ability and mental health, demonstrating that these associations can span the life course and into middle and older age.

Keywords: Cognitive ability; Data linkage; Epidemiology; Older age; Self-harm; Suicide.