Association Between Circulating Cytokines and Psychosomatic Syndromes in Patients with Mood Disorders

Area of Science:

• Psychiatry
• Immunology
• Psychosomatic Medicine

Background:

• Elevated pro-inflammatory cytokines are common in mood disorders.
• The link between inflammation and psychosomatic symptoms in depression is not well understood.

Purpose of the Study:

• To investigate the association between IL-6, TNF-α, and psychosomatic syndromes in major depression (MD) and bipolar depression (BD).
• To explore the moderating role of sex in these associations.
• To determine if psychosomatic syndromes mediate the relationship between cytokines and depressive symptoms.

Main Methods:

• Seventy-seven MD or BD outpatients were assessed for psychosomatic symptoms using DCPR-R and PHQ-15.
• Depression and mania severity were measured using BDI-II and MRS.
• Circulating IL-6 and TNF-α levels were analyzed; associations were tested using multivariate regression and mediation analyses.

Main Results:

• Both IL-6 and TNF-α were significantly associated with psychosomatic syndromes and PHQ-15 scores.
• IL-6 showed a strong association with persistent somatization.
• Psychosomatic syndromes mediated the relationship between inflammatory cytokines and depressive symptomatology, with no significant sex moderation.

Conclusions:

• The connection between inflammation and mood disorders is strongly related to psychosomatic syndromes.
• Elevated IL-6 may indicate somatization processes in depression, not direct pro-depressive effects.
• Psychosomatic syndromes are a potential clinical and therapeutic target in mood disorders with inflammation.