Comparative analysis of depression and anxiety in Psoriasis and Multiple Sclerosis: The role of body image and illness personification as serial mediators

Objective: Multiple Sclerosis (MS) and Psoriasis (Ps) are two chronic autoimmune diseases differing in terms of their external visibility (Ps > MS) and in which depression and anxiety abound. We hypothesized that depression and anxiety would be higher in Ps compared to MS and that this effect would be serially mediated by negative perception leading to negative illness personification. Method: Adult sufferers of MS and Ps (Ns = 90 and 154, respectively) were assessed as to their depression and anxiety via the Hospital Anxiety and Depression Scale (HADS), Body Perception using the Experience of Shame (ESS), and Negative Illness Personification with the BGU-IPS. Structural Equation Modeling (SEM) was employed to test the serial mediation model. Results: As expected, latent depression/anxiety was higher in Ps than in MS (b = 3.89 for anxiety, p < .001; b = 2.27 for depression, p = .024). We found support for the hypothesized serial mediation model: An indirect effect from Illness type to body perception to negative illness personification, culminating in latent depression/anxiety, accounted for 42 % of the variance of the bivariate effect. Negative Illness personification also exhibited a unique effect on depression (b = .61, p = .007). Conclusion: Perceptions of the body and the personification of illness are implicated in depression and anxiety in chronic diseases. Tailored interventions that emphasize these factors are recommended, with consideration of the type of chronic illness and its external visibility.