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Cognitive ability in early adulthood is associated with later suicide and suicide attempt: the role of risk factors over the life course

Published online by Cambridge University Press:  23 May 2012

A. Sörberg ,
P. Allebeck ,
B. Melin ,
D. Gunnell  and
T. Hemmingsson
A. Sörberg*
Affiliation:
Division of Occupational and Environmental Medicine, Department of Public Health Sciences, Karolinska Institutet, Stockholm, Sweden
P. Allebeck
Affiliation:
Division of Social Medicine, Department of Public Health Sciences, Karolinska Institutet, Stockholm, Sweden
B. Melin
Affiliation:
Division of Psychology, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
D. Gunnell
Affiliation:
School of Social and Community Medicine, University of Bristol, Bristol, UK
T. Hemmingsson
Affiliation:
Division of Occupational and Environmental Medicine, Department of Public Health Sciences, Karolinska Institutet, Stockholm, Sweden
*
*Address for correspondence: A. Sörberg, Division of Occupational and Environmental Medicine, Department of Public Health Sciences, Karolinska Institutet, Norrbacka, 171 76 Stockholm, Sweden. (Email: alma.sorberg@ki.se)
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Abstract

Background

Cognitive ability/intelligence quotient (IQ) in youth has previously been associated with subsequent completed and attempted suicide, but little is known about the mechanisms underlying the associations. This study aims to assess the roles of various risk factors over the life course in explaining the observed relationships.

Method

The present investigation is a cohort study based on data on IQ test performance and covariates, recorded on 49 321 Swedish men conscripted in 1969–1970, at ages 18–20 years. Information on suicides and hospital admissions for suicide attempt up to the age of 57 years, childhood and adult socio-economic position, and adult family formation, was obtained from linkage to national registers.

Results

Lower IQ was associated with increased risks of both suicide and suicide attempt during the 36 years of follow-up. The associations followed a dose–response pattern. They were attenuated by approximately 45% in models controlling for social background, mental ill-health, aspects of personality and behavior, adult socio-economic position and family formation. Based on one-unit decreases in IQ test performance on a nine-point scale, the hazard ratios between ages 35 and 57 years were: for suicide 1.19 [95% confidence interval (CI) 1.13–1.25], fully adjusted 1.10 (95% CI 1.04–1.18); and for suicide attempt 1.25 (95% CI 1.20–1.31), fully adjusted 1.14 (95% CI 1.09–1.20).

Conclusions

Cognitive ability was found to be associated with subsequent completed and attempted suicide. The associations were attenuated by 45% after controlling for risk factors measured over the life course. Psychiatric diagnosis, maladjustment and aspects of personality in young adulthood, and social circumstances in later adulthood, contributed in attenuating the associations.

Keywords

Cognitive epidemiologyIQmental healthpersonalitysuicidesuicide attempt

Information

Type
Original Articles
Information
Psychological Medicine , Volume 43 , Issue 1 , January 2013 , pp. 49 - 60
Copyright
Copyright © Cambridge University Press 2012

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References

Ackerman, PL, Heggestad, ED (1997). Intelligence, personality, and interests: evidence for overlapping traits. Psychological Bulletin 121, 219–245.CrossRefGoogle ScholarPubMed
Alati, R, Gunnell, D, Najman, J, Williams, G, Lawlor, D (2009). Is IQ in childhood associated with suicidal thoughts and attempts? Findings from The Mater University Study of Pregnancy and its Outcomes. Suicide and Life-Threatening Behavior 39, 282–293.CrossRefGoogle ScholarPubMed
Allebeck, P, Allgulander, C (1990 a). Psychiatric diagnoses as predictors of suicide – a comparison of diagnoses at conscription and in psychiatric-care in a cohort of 50465 young men. British Journal of Psychiatry 157, 339–344.CrossRefGoogle Scholar
Allebeck, P, Allgulander, C (1990 b). Suicide among young men – psychiatric-illness, deviant-behavior and substance abuse. Acta Psychiatrica Scandinavica 81, 565–570.CrossRefGoogle ScholarPubMed
Allebeck, P, Allgulander, C, Fisher, LD (1988). Predictors of completed suicide in a cohort of 50465 young men – role of personality and deviant behaviour. British Medical Journal 297, 176–178.CrossRefGoogle Scholar
Allebeck, P, Allgulander, C, Henningsohn, L, Jakobsson, SW (1991). Causes of death in a cohort of 50465 young men – validity of recorded suicide as underlying cause of death. Scandinavian Journal of Social Medicine 19, 242–247.CrossRefGoogle Scholar
Andersson, L, Allebeck, P, Gustafsson, JE, Gunnell, D (2008). Association of IQ scores and school achievement with suicide in a 40-year follow-up of a Swedish cohort. Acta Psychiatrica Scandinavica 118, 99–105.CrossRefGoogle Scholar
Andres, AR, Collings, S, Qin, P (2010). Sex-specific impact of socio-economic factors on suicide risk: a population-based case–control study in Denmark. European Journal of Public Health 20, 265–270.CrossRefGoogle Scholar
Batty, GD, Deary, IJ, Gottfredson, LS (2007). Premorbid (early life) IQ and later mortality risk: systematic review. Annals of Epidemiology 17, 278–288.CrossRefGoogle ScholarPubMed
Batty, GD, Shipley, MJ, Dundas, R, Macintyre, S, Der, G, Mortensen, LH, Deary, IJ (2009). Does IQ explain socio-economic differentials in total and cardiovascular disease mortality? Comparison with the explanatory power of traditional cardiovascular disease risk factors in the Vietnam Experience Study. European Heart Journal 30, 1903–1909.CrossRefGoogle ScholarPubMed
Batty, GD, Whitley, E, Deary, IJ, Gale, CR, Tynelius, P, Rasmussen, F (2010). Psychosis alters association between IQ and future risk of attempted suicide: cohort study of 1 109 475 Swedish men. British Medical Journal 340, c2506.CrossRefGoogle ScholarPubMed
Bratko, D, Butkovic, A, Vukasovic, T, Chamorro-Premuzic, T, von Stumm, S (2012). Cognitive ability, self-assessed intelligence and personality: common genetic but independent environmental aetiologies. Intelligence 40, 91–99.CrossRefGoogle Scholar
Brezo, J, Paris, J, Turecki, G (2006). Personality traits as correlates of suicidal ideation, suicide attempts, and suicide completions: a systematic review. Acta Psychiatrica Scandinavica 113, 180–206.CrossRefGoogle ScholarPubMed
Caspi, A, Moffitt, TE, Newman, DL, Silva, PA (1996). Behavioral observations at age 3 years predict adult psychiatric disorders: longitudinal evidence from a birth cohort. Archives of General Psychiatry 53, 1033–1039.CrossRefGoogle ScholarPubMed
Chamorro-Premuzic, T, Furnham, A (2004). A possible model for understanding the personality–intelligence interface. British Journal of Psychology 95, 249–264.CrossRefGoogle ScholarPubMed
David, AS, Zammit, S, Lewis, G, Dalman, C, Allebeck, P (2008). Impairments in cognition across the spectrum of psychiatric disorders: evidence from a Swedish conscript cohort. Schizophrenia Bulletin 34, 1035–1041.CrossRefGoogle ScholarPubMed
Deary, IJ, Batty, GD, Pattie, A, Gale, CR (2008). More intelligent, more dependable children live longer: a 55-year longitudinal study of a representative sample of the Scottish nation. Psychological Science 19, 874–880.CrossRefGoogle ScholarPubMed
Deary, IJ, Weiss, A, Batty, GD (2010). Intelligence and personality as predictors of illness and death. Psychological Science in the Public Interest 11, 53–79.CrossRefGoogle ScholarPubMed
Fergusson, DM, Horwood, LJ, Ridder, EM (2005). Show me the child at seven II: childhood intelligence and later outcomes in adolescence and young adulthood. Journal of Child Psychology and Psychiatry 46, 850–858.CrossRefGoogle ScholarPubMed
Fergusson, DM, Woodward, LJ, Horwood, LJ (2000). Risk factors and life processes associated with the onset of suicidal behaviour during adolescence and early adulthood. Psychological Medicine 30, 23–39.CrossRefGoogle ScholarPubMed
Gale, CR, Batty, GD, Deary, IJ (2008). Locus of control at age 10 years and health outcomes and behaviors at age 30 years: the 1970 British Cohort Study. Psychosomatic Medicine 70, 397–403.CrossRefGoogle ScholarPubMed
Gale, CR, Hatch, SL, Batty, GD, Deary, IJ (2009). Intelligence in childhood and risk of psychological distress in adulthood: The 1958 National Child Development Survey and the 1970 British Cohort Study. Intelligence 37, 592–599.CrossRefGoogle Scholar
Gravseth, HM, Mehlum, L, Bjerkedal, T, Kristensen, P (2009). Suicide in young Norwegians in a life course perspective: population-based cohort study. Journal of Epidemiology and Community Health 64, 407–412.CrossRefGoogle Scholar
Grucza, RA, Przybeck, TR, Cloninger, CR (2005). Personality as a mediator of demographic risk factors for suicide attempts in a community sample. Comprehensive Psychiatry 46, 214–222.CrossRefGoogle Scholar
Gunnell, D, Magnusson, PKE, Rasmussen, F (2005). Low intelligence test scores in 18 year old men and risk of suicide: cohort study. British Medical Journal 330, 167–171.CrossRefGoogle ScholarPubMed
Hagnell, O, Lanke, J, Rorsman, B (1981). Suicide rates in the Lundby study: mental illness as a risk factor for suicide. Neuropsychobiology 7, 248–253.CrossRefGoogle ScholarPubMed
Hemmingsson, T, Kriebel, D (2003). Smoking at age 18–20 and suicide during 26 years of follow-up – how can the association be explained? International Journal of Epidemiology 32, 1000–1004.CrossRefGoogle ScholarPubMed
Hemmingsson, T, Melin, B, Allebeck, P, Lundberg, I (2006). The association between cognitive ability measured at ages 18–20 and mortality during 30 years of follow-up – a prospective observational study among Swedish males born 1949–51. International Journal of Epidemiology 35, 665–670.CrossRefGoogle ScholarPubMed
Hemmingsson, T, Melin, B, Allebeck, P, Lundberg, I (2009). Cognitive ability in adolescence and mortality in middle age: a prospective life course study. Journal of Epidemiology and Community Health 63, 697–702.CrossRefGoogle ScholarPubMed
Jiang, GX, Rasmussen, F, Wasserman, D (1999). Short stature and poor psychological performance: risk factors for attempted suicide among Swedish male conscripts. Acta Psychiatrica Scandinavica 100, 433–440.CrossRefGoogle ScholarPubMed
Johansson, LM, Sundquist, J, Johansson, SE, Qvist, J, Bergman, B (1997). The influence of ethnicity and social and demographic factors on Swedish suicide rates. Social Psychiatry and Psychiatric Epidemiology 32, 165–170.CrossRefGoogle ScholarPubMed
Jokela, M, Batty, GD, Deary, IJ, Gale, CR, Kivimaki, M (2009). Low childhood IQ and early adult mortality: the role of explanatory factors in the 1958 British Birth Cohort. Pediatrics 124, e380–e388.CrossRefGoogle ScholarPubMed
Jollant, F, Lawrence, NS, Olie, E, O'Daly, O, Malafosse, A, Courtet, P, Phillips, ML (2010). Decreased activation of lateral orbitofrontal cortex during risky choices under uncertainty is associated with disadvantageous decision-making and suicidal behavior. Neuroimage 51, 1275–1281.CrossRefGoogle ScholarPubMed
Karlsson, H, Ahlborg, B, Dalman, C, Hemmingsson, T (2010). Association between erythrocyte sedimentation rate and IQ in Swedish males aged 18–20. Brain, Behavior, and Immunity 24, 868–873.CrossRefGoogle ScholarPubMed
Keilp, JG, Gorlyn, M, Oquendo, MA, Burke, AK, Mann, JJ (2008). Attention deficit in depressed suicide attempters. Psychiatry Research 159, 7–17.CrossRefGoogle ScholarPubMed
Larsson, D, Hemmingsson, T, Allebeck, P, Lundberg, I (2002). Self-rated health and mortality among young men: what is the relation and how may it be explained? Scandinavian Journal of Public Health 30, 259–266.CrossRefGoogle ScholarPubMed
Lilieblad, B, Stahlberg, A (1977). Reliabilitet hos psykologiska bedömningar vid inskrivningsprovning [Reliability of psychological assessments at conscription]. Stockholm FOA rapport 1977; C55011-H7. Försvarets Forskningsanstalt: Stockholm.Google Scholar
Luciano, M, Wainwright, MA, Wright, MJ, Martin, NG (2006). The heritability of conscientiousness facets and their relationship to IQ and academic achievement. Personality and Individual Differences 40, 1189–1199.CrossRefGoogle Scholar
Nock, MK, Borges, G, Bromet, EJ, Cha, CB, Kessler, RC, Lee, S (2008). Suicide and suicidal behavior. Epidemiology Review 30, 133–154.CrossRefGoogle ScholarPubMed
Ohberg, A, Lonnqvist, J (1998). Suicides hidden among undetermined deaths. Acta Psychiatrica Scandinavica 98, 214–218.CrossRefGoogle ScholarPubMed
Osler, M, Nybo Andersen, A-M, Nordentoft, M (2008). Impaired childhood development and suicidal behaviour in a cohort of Danish men born in 1953. Journal of Epidemiology and Community Health 62, 23–28.CrossRefGoogle Scholar
O'Toole, BI, Cantor, C (1995). Suicide risk factors among Australian Vietnam era draftees. Suicide and Life-Threatening Behavior 25, 475–488.CrossRefGoogle ScholarPubMed
Pearce, CM, Martin, G (1993). Locus of control as an indicator of risk for suicidal behaviour among adolescents. Acta Psychiatrica Scandinavica 88, 409–414.CrossRefGoogle ScholarPubMed
Pickles, A, Aglan, A, Collishaw, S, Messer, J, Rutter, M, Maughan, B (2010). Predictors of suicidality across the life span: The Isle of Wight Study. Psychological Medicine 40, 1453–1466.CrossRefGoogle ScholarPubMed
Reeve, CL, Bonaccio, S (2008). Does test anxiety induce measurement bias in cognitive ability tests? Intelligence 36, 526–538.CrossRefGoogle Scholar
Roberts, BW, Kuncel, NR, Shiner, R, Caspi, A, Goldberg, LR (2007). The power of personality: the comparative validity of personality traits, socioeconomic status, and cognitive ability for predicting important life outcomes. Perspectives on Psychological Science 2, 313–345.CrossRefGoogle ScholarPubMed
Taylor, MD, Hart, CL, Smith, GD, Whalley, LJ, Hole, DJ, Wilson, V, Deary, IJ (2005). Childhood IQ and marriage by mid-life: the Scottish Mental Survey 1932 and the Midspan studies. Personality and Individual Differences 38, 1621–1630.CrossRefGoogle Scholar
Tidemalm, D, Elofsson, S, Stefansson, CG, Waern, M, Runeson, B (2005). Predictors of suicide in a community-based cohort of individuals with severe mental disorder. Social Psychiatry and Psychiatric Epidemiology 40, 595–600.CrossRefGoogle Scholar
Webb, RT, Langstrom, N, Runeson, B, Lichtenstein, P, Fazel, S (2011). Violent offending and IQ level as predictors of suicide in schizophrenia: national cohort study. Schizophrenia Research 130, 143–147.CrossRefGoogle ScholarPubMed
Weiss, A, Gale, CR, Batty, GD, Deary, IJ (2009). Emotionally stable, intelligent men live longer: The Vietnam Experience Study cohort. Psychosomatic Medicine 71, 385–394.CrossRefGoogle ScholarPubMed