Arvo building, auditorium F114, address: Arvo Ylpön katu 34.
Doctoral defence of Lic.Med. Antti Torikka
The field of science of the dissertation is Adolescent Psychiatry.
The opponent is professor Solja Niemelä (University of Oulu). Professor Riittakerttu Kaltiala-Heino acts as the custos.
The language of the dissertation defence is Finnish.
Depression and Substance Use in Middle Adolescence
This thesis studied the associations between self-reported depression and substance use and potential gender differences in the associations of depression with substance use in a large non selected middle-adolescence population. The study moreover investigated the association between substance use and suicidal ideation, which is known to be associated with depression.
The present study also examined changes in adolescent depression and alcohol use from 2000 to 2011. More specifically, it examined whether changes in depression and alcohol use over time vary according to the socio-economic background of the family in terms of parental unemployment and education and whether time trends in adolescent alcohol use differed among adolescents with and without depression.
Among girls, the rate of severe depression was slightly higher in the beginning of the second decade of this century (2010) than in the beginning of the first decade (2000). Among boys no such trend was found. A novel finding of the present study is that there was a clear rising trend in depression over time among both boys and girls whose parents had low level of education and who were unemployed. The major finding of the present study is that contrary to the decreasing trends in the sample as a whole, frequent drinking and drunkenness did not decrease over time among disadvantaged, depressed adolescents. Rather, frequent drinking and drunkenness actually increased over time among this disadvantaged group.
The present study confirmed on population level the association of depression with frequent alcohol use and use of substances other than alcohol. The association between depression and any experiment with substances other than alcohol was stronger than that between depression and frequent alcohol use or frequent drunkenness. Although there were differences in substance use patterns between girls and boys, and depression among girls was more common than among boys, there were no gender differences in associations between depression and substance use.
Frequent alcohol use and substance use other than alcohol indicated risk of severe suicidal ideation independently of depressive symptoms in middle adolescence, and the relationships were most pronounced with the reported use of substances other than alcohol.
The present study is based on the School Health Promotion Study conducted by the National Institute for Health and Welfare, a questionnaire survey designed to examine the health, health behaviour and school experiences of Finnish teenagers conducted annually since 1995. The study on the associations between self-reported depression and substance use and the study on the association between substance use and suicidal ideation are based on the 1997 survey. This material comprises the responses of pupils of the 8th and 9th grades of secondary schools (aged 14-16 years, N=17,643) in two regions of Finland. Since 2000, data collection has taken place in different regions in odd and even years so that pooled samples of consecutive years (2000-2001, 2002-2003, 2004-2005, 2006-2007, 2008-2009, and 2010-20011) cover the whole Finland. The data on the depression and alcohol use time trend studies include those 535 schools that participated in all six of the surveys. Altogether, 618,084 pupils were present on the survey days and returned the questionnaire in these schools.
Reducing health inequalities likely requires societal action. At the individual level, school health and welfare services and primary healthcare should develop skills and interventions to motivate and support different adolescent groups to reduce alcohol use. Targeting preventive efforts at disadvantaged adolescents and improving the living conditions of families might be useful in reducing equality gaps.
Health care professionals have a special challenge to recognize depression among adolescents engaging in frequent drinking and substance use and the risk for substance use among depressed adolescents. It is also a special challenge for school and health care professionals to identify possible suicidality in adolescents who drink heavily and use substances, whether or not they exhibit depression. Collaboration between school and health care professionals and parents is needed to improve opportunities for early interventions.
The dissertation is published in the publication series of Acta Universitatis Tamperensis; 2290, Tampere University Press, Tampere 2017. The dissertation is also published in the e-series Acta Electronica Universitatis Tamperensis; 1793, Tampere University Press 2017.