Early-onset depressive disorders predict the use of addictive substances in adolescence: a prospective study of adolescent Finnish twins

Authors

  • Elina Sihvola,

    1. Department of Public Health, University of Helsinki, Finland,
    2. Department of Psychiatry, Helsinki University Central Hospital, Helsinki, Finland,
    Search for more papers by this author
  • Richard J. Rose,

    1. Department of Psychological and Brain Sciences, Indiana University, Bloomington, USA,
    Search for more papers by this author
  • Danielle M. Dick,

    1. Virginia Institute for Psychiatric and Behavioral Genetics, Department of Psychiatry, Virginia Commonwealth University, Richmond, VA, USA,
    Search for more papers by this author
  • Lea Pulkkinen,

    1. Department of Psychology, University of Jyväskylä, Jyväskylä, Finland,
    Search for more papers by this author
  • Mauri Marttunen,

    1. Department of Mental Health and Alcohol Research, National Public Health Institute, Helsinki, Finland and
    2. Department of Adolescent Psychiatry, University of Helsinki and Helsinki University Central Hospital, Helsinki, Finland
    Search for more papers by this author
  • Jaakko Kaprio

    1. Department of Public Health, University of Helsinki, Finland,
    2. Department of Mental Health and Alcohol Research, National Public Health Institute, Helsinki, Finland and
    Search for more papers by this author

Elina Sihvola, Department of Public Health (5th floor), Mannerheimintie 172, PO Box 41 00014, University of Helsinki, Finland. E-mail: elina.sihvola@helsinki.fi

ABSTRACT

Aims  To explore the developmental relationships between early-onset depressive disorders and later use of addictive substances.

Design, setting and participants  A sample of 1545 adolescent twins was drawn from a prospective, longitudinal study of Finnish adolescent twins with baseline assessments at age 14 years and follow-up at age 17.5 years.

Measurements  At baseline, DSM-IV diagnoses were assessed with a professionally administered adolescent version of Semi-Structured Assessment for Genetics of Alcoholism (C-SSAGA-A). At follow-up, substance use outcomes were assessed via self-reported questionnaire.

Findings  Early-onset depressive disorders predicted daily smoking [odds ratio (OR) 2.29, 95% confidence interval (CI) 1.49–3.50, P < 0.001], smokeless tobacco use (OR = 2.00, 95% CI 1.32–3.04, P = 0.001), frequent illicit drug use (OR = 4.71, 95% CI 1.95–11.37, P = 0.001), frequent alcohol use (OR = 2.02, 95% CI 1.04–3.92, P = 0.037) and recurrent intoxication (OR = 1.83, 95% CI 1.18–2.85, P = 0.007) 3 years later. ORs remained significant after adjustment for comorbidity and exclusion of baseline users. In within-family analysis of depression-discordant co-twins (analyses that control for shared genetic and familial background factors), early-onset depressive disorders at age 14 predicted significantly frequent use of smokeless tobacco and alcohol at age 17.5.

Conclusions  Our results suggest important predictive associations between early-onset depressive disorders and addictive substance use, and these associations appear to be independent of shared familial influences.

Ancillary