Is alexithymia a risk factor for major depression, personality disorder, or alcohol use disorders? A prospective population-based study.

OBJECTIVE: Disagreements concerning the stability of alexithymia and its ability to predict subsequent psychiatric disorders prevail. The aim of this 7-year follow-up study was to examine whether alexithymia predicts subsequent major depression, personality disorder, or alcohol use disorders in a population-based sample.

METHODS: The four-phase Kuopio Depression Study (KUDEP) was conducted in the eastern part of Central Finland. The study population (aged 25-64, n=2050) was randomly selected from the National Population Register. Data were collected in 1998, 1999, and 2001. In 2005, a subsample (n=333, 43 were excluded) of the 3-year follow-up population (1998-2001) was gathered and their diagnoses of mental disorders were confirmed by the Structure Clinical Interview for DSM-IV Axis I (SCID-I). Alexithymia was measured using the Toronto Alexithymia Scale (TAS-20) and depressive symptoms using the Beck Depression Inventory (BDI-21). For both of these measures, two groups were formed based on the median of their sum score (summing the 1998, 1999, and 2001 scores). Logistic regression analyses were performed.

RESULTS: BDI sum scores, but not those of TAS, were associated with subsequent major depressive disorder, personality disorder, and alcohol use disorders in 2005. The BDI sum scores explained 35.7% of the variation in concurrent TAS sum scores.

CONCLUSION: Alexithymia did not predict diagnoses of major depressive disorder, personality disorder, or alcohol use disorders. Alexithymia was closely linked to concurrent depressive symptoms. Thus, depressive symptoms may act as a mediator between alexithymia and psychiatric morbidity.