Prospective Relations between Childhood Temperament, Adolescent Alexithymia, and Young Adult Substance Use Disorder and Depression in a Finnish Birth Cohort

Introduction: Alexithymia is a multi-dimensional construct that describes difficulties a) identifying and b) describing feelings as well as having an c) externally-oriented cognitive style. Some research has shown this condition to be correlated with a number of psychiatric outcomes, including substance use disorder (SUD) and depression; however, longitudinal studies are needed to examine both the developmental precursors and the sequelae of alexithymia. To fill this need, we used long-term longitudinal data to examine a developmental model leading from difficult temperament characteristics in childhood to the three dimensions of alexithymia in adolescence and, ultimately, to SUD and depression in young adulthood, while accounting for early contextual risk and adolescent substance use and internalizing symptoms. We also explored potential gender moderation.

Methods: Multiple group path analyses were conducted using data from the Northern Finland Birth Cohort 1986 (N = 6,963). Analyses used data collected during prenatal/birth, childhood, adolescence, and young adulthood periods. Questionnaire measures included the Toronto Alexithymia Scale, the Rutter Children’s Behavior Questionnaire, and the Youth Self-Report. Population register data provided diagnoses of SUD and depression in young adulthood.

Results: For all youth, the alexithymia dimension of difficulties identifying feelings (DIF) had a positive association with depression in young adulthood (β=.13, p < .05); however, none of the alexithymia dimensions was associated with SUD. For females but not males, neuroticism in childhood predicted both DIF (β = -.26, p= < .05) and difficulties describing feelings (DDF; β = -.20, p < .05), and hyperactivity-aggression predicted externally-oriented thinking (EOT; β = -.17, p < .05). For boys and girls, prenatal/birth contextual risk was a long-term predictor of each dimension of alexithymia (DIF: β = .03, p < .05; DDF: β = .05, p < .05; and EOT: β = .04, p < .05), adolescent substance use (β = .14, p < .05), and young adult depression (β = .06, p < .05).

Conclusions: This study helps identify the predictors and consequences of alexithymia to guide the development of interventions designed to prevent this condition and its adverse sequelae, such as depression. Moreover, understanding the role of early contextual risk in alexithymia, SUD, and depression can aid in screening and intervention efforts targeting at-risk youth.