“Our similarities are different” The relationship between alexithymia and depression

•There is a crescent relationship between depression and alexithymia.•A core difficulty in alexithymia is to discern feelings from body sensations.•The somatization and embodiment are facets of alexithymia. Alexithymia is a multi-faceted personality trait, which is the inability to recognize and describe emotions. It is associated with a multitude of mental health problems, and its implication for the diagnosis and treatment of depression remains unclear. The current study explored the nuances of the relationship between alexithymia and depression in a sample of 210 patients with depression. We assessed alexithymia with the 20-Item Toronto Alexithymia Scale (TAS-20) and depression with the Beck Depression Inventory (BDI-I). The mean TAS-20 score was 57.47 ± 10.63, and the mean BDI-I score was 49.33±9.24. We explored the network structure of alexithymia and depression. Items related to difficulties in identifying, describing, and expressing feelings were prominent in the alexithymia network. Joy, guilt, and self-dislike stand out in the depression network. In our analysis, we were able to show the crescent relationship between depression and alexithymia, with an inflection point at a TAS-20 score of 53. Although the correlation-concordance index was moderate (0.41; 95 %CI: 0.29–0.51), both scales greatly overlap. In the joint network of alexithymia and depression, we could identify bridge (i.e., connecting) items between alexithymia and depression. These were difficulties understanding and relating feelings to physical and body sensations on the alexithymia side, and self-dislike, crying, and somatic concern on the depression side. Taken together, they point to the pivotal role of alexithymia in the somatization/embodiment of emotions and feelings in depression.