Background The ability of melatonin to reduce the activity of the sympathetic nervous system tone and of pituitary-adrenal system ensures its anti-stress properties. It can be used to reduce psycho-emotional manifestations of chronic pain in patients with psoriatic arthritis (PsA).

Objectives To evaluate the effect of combined therapy with the use of melatonin on the expression of psycho-emotional disorders, and pain in patients with PsA.

Methods High levels of anxiety and depressive disorders were established in the survey on Spielberger Anxiety Scale and on Hamilton Rating Scale for Depression (HRDS) in 43 patients with PsA (≥5 SJC and ≥5 TJC; CRP ≥0.3 mg/dL). The quality of life was studied by questionnaire Medical Outcomes Study Short Form (SF-36); the severity of morning stiffness, pain, patient's health status (EWS) - using the 100-mm visual analog scale (VAS). All patients were receiving a stable dose of MTX for at least 6 months. They were divided into two groups; 1 group (n=22) additionally received 3 mg of melatonin at bedtime for 2 months of observation

Results At the end of the observation period the frequency and the level of severity of depression by HRDS (p=0.0098), and the index of personal anxiety (P=0.009) in group 1 decreased. In the 2nd group above mentioned parameters have not changed. On the 1 group data of SF-36 evaluation: the physical health component has improved - the increase of RP and BP 57.4% and 37.8% from the baseline; vital activity and role functioning due to emotional state, have also increased by 35.6% and 43.5%, respectively. In the 2nd group (n=22) investigated parameters have not undergone significant changes in dynamics. In the 1 receiving melatonin group TJC and SJC have decreased by 15% and 22% (p=0.0079, p=0.0022, respectively) and their dynamics in the 2nd group was less significant (p=0.013 and p=0.017, respectively). Also, patients in group 1 have highly significant (p<0.001) reduction in the severity of morning stiffness and joint pain, and in the 2nd group the changes were less significant (respectively, p=0.043, p=0.016). Positive dynamics of CRP in group 1 was more significant (p=0.003), than it was in 2 patients` group (p=0.033).

Conclusions In the group of patients treated with melatonin was noted improvement in general condition (a significant improvement in the parameters of the physical components of health, reduction of depressive and psycho-vegetative disorders) and also more significant decrease of the intensity of pain and of morning stiffness duration, of TJC and SJC, than in not treated with melatonin patients. Inclusion of Melatonin in the comprehensive PsA therapy promotes not only reduction of depression symptoms and sleep disorders, but also reduces the severity of the chronic pain manifestations and, consequently, improves the quality of life of patients with this disease

Disclosure of Interest None declared