About the Authors

Leena Kovanen

Affiliations Department of Mental Health and Substance Abuse Services, National Institute for Health and Welfare, Helsinki, Finland, Department of Alcohol, Drugs and Addiction, National Institute for Health and Welfare, Helsinki, Finland

Sirkku T. Saarikoski

Affiliation Department of Alcohol, Drugs and Addiction, National Institute for Health and Welfare, Helsinki, Finland

Arpo Aromaa

Affiliation Division of Welfare and Health Policies, National Institute for Health and Welfare, Helsinki, Finland

Jouko Lönnqvist

Affiliations Department of Mental Health and Substance Abuse Services, National Institute for Health and Welfare, Helsinki, Finland, Department of Psychiatry, University of Helsinki, Helsinki, Finland

Timo Partonen

timo.partonen@thl.fi

Affiliation Department of Mental Health and Substance Abuse Services, National Institute for Health and Welfare, Helsinki, Finland

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: STS AA JL TP. Performed the experiments: LK. Analyzed the data: LK. Contributed reagents/materials/analysis tools: STS AA JL TP. Wrote the paper: LK STS AA JL TP.