A large Finnish study sought to determine if there were any links to adulthood mood disorders and teenage drinking, smoking, and coffee use.

A birth cohort study, using a large dataset from Finland, aimed to clarify any associations between adolescent smoking, coffee drinking, and alcohol consumption in relation to the development of mood disorders, such as major depression and bipolar disorder later in adulthood.

While links between adolescent coffee habits in adolescents and mood disorders in adulthood were not seen, researchers did find evidence for later health issues related to smoking and alcohol.

While previous studies have looked at these various relationships, some of the findings have been contradictory or limited by the types of study design, and most research only examined the impact on major depression. This study specifically included the development of bipolar depression as an outcome, and linked population data to health registry data.

A group of 7660 participants were evaluated from the Northern Finland Birth Cohort 1986 Study, an ongoing study that represents the majority of children born alive in 2 provinces.

A 2-phase follow-up study was conducted in 2001-2002, when participants were 15 or 16-years of age, asking participants to answer a questionnaire regarding health and wellbeing in the Youth Self Report (YSR), as well as answering questions about cigarette and coffee consumption. Participants were also asked to fill out a second questionnaire about their alcohol consumption.

Diagnoses of bipolar depression or major depression were retrieved from 2 national health care registers until the end of 2018, when the participants were 32 or 33.

Of the 7660 participants, 879 (11.5%) were diagnosed with major depression and 85 (1.1%) were diagnosed with bipolar depression by age 33.

Using multinominal logistic regression analysis, researchers found significant associations between alcohol consumption and bipolar depression, and weaker ones for major depression.

An association between bipolar disorder and alcohol consumption remained significant after adjusting for sex, parental psychiatric disorders, illicit drug use, total YSR score, and family structure (OR, 1.22; 95% CI, 1.01-1.47).

While a link was seen between major depression and alcohol consumption when adjusting for sex, parental psychiatric disorders, and family structure (OR, 1.16; 95% CI, 1.10-1.29), it weakened after further adjustment.

Modest associations for excessive drinking of 3 or more times a month was found for both bipolar depression (OR, 2.54; 95% CI, 1.34-4.84) and major depression (OR, 1.66; 95% CI, 1.30-2.12). However, when adjusted for parental psychiatric disorders, the link for major depression remained significant, but the evidence for bipolar depression weakened; after adding illicit drug use as a covariate, the link to major depression also weakened.

After adjusting for all covariates, the link between the number of cigarettes smoked a day and bipolar depression remained statistically significant (OR, 1.23; 95% CI, 1.01-1.50). The association for cigarettes and major depression was statistically significant (OR, 1.11; 95% CI, 1.02-1.20) in an earlier model but not after adjusting for answers on the YSR.

The study was limited due to lack of knowledge of health symptoms before the age of 16. In addition, the use of self-reported information may have led to less accurate results and failure to report substance report. Furthermore, a relatively low number of patients with bipolar depression gave limited power for identifying associations for consumption frequencies measured by categorical variables.

“Our findings demonstrate that both adolescent cigarette smoking and alcohol consumption are associated with increased risk for subsequent mood disorders,” the researchers said. “These relationships are relatively well established for MD, but the current study points to the relationships being even more pronounced for BP,” they continued.

Reference

Ingeborg B, Anni-Emilia A, Jorgen G. B, et al. The relationships between use of alcohol, tobacco and coffee in adolescence and mood disorders in adulthood. Acta Psychiatrica Scandinavica. Published online September 30, 2022.

https://doi.org/10.1111/acps.13506