Researchers look at link between inability to express emotions and sleep disturbances

A group of Finnish investigators has explored the relationship between alexithymia (the inability to express emotions) and sleep disturbances in the 2008 January issue of Psychotherapy and Psychosomatics.

The Authors analyzed the association of alexithymic features with sleep disorder symptoms in a representative sample of the Finnish adult population (n = 5,388: 2,464 men and 2,924 women). Their main interest was on whether the association was independent of depressive symptoms, obesity, and the sociodemographic covariates of alexithymia and insomnia. Alexithymia was assessed with the TAS-20 and with its three factor scales: “difficult identifying feelings” (DIF), “difficult describing feelings”(DDF) and “externally oriented thinking” (EOT).

Sleep disturbance was defined by the following question: ‘Have you had any of the following symptoms and troubles within the last month: (…) sleeping disorders or insomnia?’. Depressive symptoms were assessed with the Beck Depression Inventory (BDI). Obesity and overweight were defined by waist circumference measured during the health examination. The following socio-demographic variables were considered to be relevant covariates for studying the association of alexithymia with sleep disturbance: age, sex, level of education and household income.

At the end of the study, the Authors found support for an independent association between alexithymic features and insomnia-related symptoms in both sexes. This association is sex-specific in that it is modulated differently by depression, obesity and education in men than in women. The DIF factor scale is the best predictor of insomnia-related symptoms in multivariable logistic regression models compared with other indicators of alexithymia. The EOT factor scale is related to sleep disturbances in men only.