Childhood socio-economic status, school failure and drug abuse: a Swedish national cohort study

Authors

  • Karl Gauffin,

    Corresponding author
    1. Department of Public Health Sciences, Karolinska Institutet, Stockholm, Sweden
    • Centre for Health Equity Studies (CHESS), Karolinska Institutet/Stockholm University, Stockholm, Sweden
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  • Bo Vinnerljung,

    1. Department of Social Work, Stockholm University, Stockholm, Sweden
    2. National Board of Health and Welfare, Stockholm, Sweden
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  • Mats Fridell,

    1. Department of Psychology, Lund University, Lund, Sweden
    2. Clinical Psychology, Linnaeus University, Växjö, Sweden
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  • Morten Hesse,

    1. Centre for Alcohol and Drug Research, Aarhus University, Copenhagen S, Denmark
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  • Anders Hjern

    1. Centre for Health Equity Studies (CHESS), Karolinska Institutet/Stockholm University, Stockholm, Sweden
    2. Clinical Epidemiology/Department of Medicine, Karolinska Institutet, Stockholm, Sweden
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Correspondence to: Karl Gauffin, Centre for Health Equity Studies (CHESS), Stockholm University/Karolinska Institutet, 10691 Stockholm, Sweden. E-mail: karl.gauffin@chess.su.se

Abstract

Aim

To investigate whether socio-economic status (SES) in childhood and school failure at 15 years of age predict illicit drug abuse in youth and young adulthood.

Designsetting and participants

Register study in a Swedish national cohort born 1973–88 (n = 1 405 763), followed from age 16 to 20–35 years. Cox regression analyses were used to calculate hazard ratios (HR) for any indication of drug abuse.

Measurements

Our outcomes were hospital admissions, death and criminality associated with illicit drug abuse. Data on socio-demographics, school grades and parental psychosocial problems were collected from censuses (1985 and 1990) and national registers. School failure was defined as having mean school grades from the final year in primary school lower than −1 standard deviation and/or no grades in core subjects.

Findings

School failure was a strong predictor of illicit drug abuse with an HR of 5.87 (95% CI: 5.76–5.99) after adjustment for age and sex. Childhood SES was associated with illicit drug abuse later in life in a stepwise manner. The lowest stratum had a HR of 2.28 (95% CI: 2.20–2.37) compared with the highest stratum as the reference, when adjusted for other socio-demographic variables. In the fully adjusted model, the effect of SES was greatly attenuated to an HR of 1.23 (95% CI: 1.19–1.28) in the lowest SES category, while the effect of school failure remained high with an HR of 4.22 (95% CI: 4.13–4.31).

Conclusions

School failure and childhood socio-economic status predict illicit drug abuse independently in youth and young adults in Sweden.

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