Phototherapy with ultraviolet radiation: a study of hormone parameters and psychological effects

Background and objectives Patients report well‐being as they are treated with phototherapy. We investigated hormone parameters and psychological well‐being after phototherapy in a placebo‐controlled study. Methods A total of 77 patients with dermatological conditions and 22 healthy volunteers were divided into four groups. The patients received phototherapy either on the whole body or only on hands and/or feet. The volunteers were given either whole‐body phototherapy or placebo light. Serum or plasma samples were analysed for cortisol, calcium, magnesium, phosphate, TSH, T₄, T₃ and 25‐hydroxyvitamin D, and urine samples for cortisol. Patients and volunteers answered a questionnaire before and 6 weeks after phototherapy/placebo light. Psychiatric ratings were performed according to the Comprehensive Psychopathological Self‐rating Scale for Affective Syndromes, a self‐report version of which has been transformed to correspond to the Montgomery‐Åsberg Depression Rating Scale (MADRS). Results In the patients who received whole‐body irradiation, we observed a significant improvement in both MADRS score and cognitive‐symptom score after the completion of phototherapy. We also observed a significantly higher level of 25‐hydroxyvitamin D after phototherapy, but no difference in the other hormone parameters. Conclusion Whole‐body phototherapy of patients with dermatological conditions results in improved well‐being and significantly higher levels of 25‐hydroxyvitamin D in serum.