TitleIntelligence and neuroticism in relation to depression and psychological distress: Evidence from two large population cohorts.
Publication TypeJournal Article
Year of Publication2017
AuthorsNavrady, LB, Ritchie, SJ, W Y Chan, S, Kerr, DM, Adams, MJ, Hawkins, EH, Porteous, D, Deary, IJ, Gale, CR, Batty, GD, McIntosh, AM
JournalEur Psychiatry
Date Published06/2017
KeywordsAdolescent, Adult, Aged, Aged, 80 and over, Depressive Disorder, Major, Female, Health Surveys, Humans, Intelligence, Male, Middle Aged, Neuroticism, Personality, Psychiatric Status Rating Scales, Risk Factors, Stress, Psychological, Young Adult

BACKGROUND: Neuroticism is a risk factor for selected mental and physical illnesses and is inversely associated with intelligence. Intelligence appears to interact with neuroticism and mitigate its detrimental effects on physical health and mortality. However, the inter-relationships of neuroticism and intelligence for major depressive disorder (MDD) and psychological distress has not been well examined.

METHODS: Associations and interactions between neuroticism and general intelligence (g) on MDD, self-reported depression, and psychological distress were examined in two population-based cohorts: Generation Scotland: Scottish Family Health Study (GS:SFHS, n=19,200) and UK Biobank (n=90,529). The Eysenck Personality Scale Short Form-Revised measured neuroticism and g was extracted from multiple cognitive ability tests in each cohort. Family structure was adjusted for in GS:SFHS.

RESULTS: Neuroticism was strongly associated with increased risk for depression and higher psychological distress in both samples. Although intelligence conferred no consistent independent effects on depression, it did increase the risk for depression across samples once neuroticism was adjusted for. Results suggest that higher intelligence may ameliorate the association between neuroticism and self-reported depression although no significant interaction was found for clinical MDD. Intelligence was inversely associated with psychological distress across cohorts. A small interaction was found across samples such that lower psychological distress associates with higher intelligence and lower neuroticism, although effect sizes were small.

CONCLUSIONS: From two large cohort studies, our findings suggest intelligence acts a protective factor in mitigating the effects of neuroticism on psychological distress. Intelligence does not confer protection against diagnosis of depression in those high in neuroticism.

Alternate JournalEur. Psychiatry
PubMed ID28365468
PubMed Central IDPMC5486156
Grant ListMC_UP_A620_1015 / / Medical Research Council / United Kingdom
104036 / / Wellcome Trust / United Kingdom
MC_QA137853 / / Medical Research Council / United Kingdom
MC_UU_12011/2 / / Medical Research Council / United Kingdom
MC_U147585819 / / Medical Research Council / United Kingdom
MR/K026992/1 / / Medical Research Council / United Kingdom
/ / Wellcome Trust / United Kingdom
CZD/16/6 / / Chief Scientist Office / United Kingdom