Alexithymia refers to difficulties in identifying one’s own feelings and in describing feelings to others as well as to an unimaginative and externally oriented way of thinking. According to earlier studies, alexithymia seems to be associated with several mental health disorders and somatic diseases. Results from epidemiological studies on the prevalence and socio-demographic associations of alexithymia have so far been somewhat contradictory. Moreover, there are no earlier nationally representative studies on the epidemiology of alexithymia. The aims of the present dissertation were as follows: to find out the prevalence and socio-demographic correlates of alexithymia in the Finnish general population, and if alexithymia is associated with occupational health, health-related quality of life and somatization, three factors with significance to public health.
This dissertation is based on data from the Health 2000 Study. The gathering of data took place in Finland in 2000 - 2001. A large national network coordinated by the National Public Health Institute was responsible for the planning and execution of the field phase of this multidisciplinary epidemiological survey. It was designed according to the concept of a two-stage stratified cluster sampling, and comprised adults aged 30 years and over. Of the nationally representative sample of 8028 subjects, 5454 were selected as the basic sample for this dissertation.
The prevalence of alexithymia was 9.9%. Men (11.9%) were significantly more commonly alexithymic than women (8.1%). The mean TAS-20 score for the whole sample was 45.8, for men 47.8 and for women 43.9, the sex difference being significant. Of the three dimensions of alexithymia, difficulties identifying feelings (DIF) was not associated with sex while the scores of difficulties describing feelings (DDF) and externally oriented thinking (EOT) were higher for men. The prevalence of alexithymia and the mean TAS-20 score increased significantly with age. Of other sociodemographic variables, alexithymia was associated with being unmarried or widowed, with lower education levels and with lower income. Occupational burnout was measured with the Maslach Burnout Inventory – General Survey in a sample of 3322 working people. DIF and DDF were stronger determinants of burnout than EOT. According to Sobel-Goodman mediation analyses, the impact of alexithymia on depression was partly medi! ated through occupational burnout. Health-related quality of life (HRQoL) was measured with the 15D and alexithymia was found to be significantly associated with poorer HRQoL. In the case of dichotomized alexithymia as well as the total TAS-20 score and DIF score, the difference in 15D scores were also clinically noteworthy. Somatization, operationalized as somatic symptom reporting on the Hopkins Symptom Checklist – 90 somatization subscale, was significantly associated with alexithymia. According to structural equation modelling, all alexithymia variables were statistically significant. However, the correlation between somatic symptom reporting and EOT was negligible.
In conclusion, every tenth individual in Finland is alexithymic. Men are more commonly alexithymic than women, and older adults more commonly than younger adults. Alexithymia is associated with lower levels of education and income, with occupational burnout, with poorer HRQoL and with somatization. It is important to recognize alexithymia as it may have a negative impact on the outcome of various disorders and on treatment relationships. In future, prospective population studies on the predictive value and the stability of alexithymia are needed. Furthermore, studies on etiological factors of alexithymia as well as on appropriate treatment strategies for helping alexithymic people are required.
