Objectives
The aim of the present study was to evaluate the efficacy of duloxetine in generalized anxiety disorder and the its compatibility and synergy with non-pharmacological instruments.
Methods
This observational study was carried-out in 130 patients (80 women and 50 men) (Table I) with generalized anxiety disorder recruited among outpatients of the Operative Unit of Mental Health, district 13, ASL Caserta. The patients were subdivided into two cohorts: the first cohort was treated with duloxetine 30 mg/die (70 patients), the second with duloxetine 30 mg/die plus a group trained in stress control counseling (60 patients). They were assessed through the Hamilton Rating Scale for Anxiety (HAM-A) administered at the 1st, 2nd, 3rd, 4th, 5th, 6th, 8th, 10th, and 12th week of treatment, and the Anxiety Scale Questionnaire (ASQ) administered at T0, T30, T60 and follow-up at T90 days.
Results
In the group treated with duloxetine (dulo) + stress control counseling (scc), the improvement was more rapid than the group treated only with dulo (Fig. 1); in the first 4 weeks, 65% of patients treated with dulo plus scc and 53% of patients treated with dulo alone responded to treatment significantly; while regarding remission, there were no statistically significant differences (Fig. 2). Dulo 30 mg + scc-treated patients also showed significantly greater improvements compared with dulo 30 mg-treated patients on each of the secondary efficacy measures (Fig. 3); with the scale ASQ, we observed that the sum score of A + B improved significantly in the first month of treatment, gradually stabilizing in the group treated with dulo plus scc (Fig. 4).
Conclusions
The results of this observational study suggest that duloxetine is effective and well tolerated at a dose of 30 mg/die for the treatment of GAD. Patients who received the drug plus the educational training group in stress control counseling have achieved a significant improvement, with reduced severity of anxiety symptoms and improving the overall performance, faster than the group treated only with the medication. These improvements were clinically significant, as indicated by the good response from the sustained improvement and remission rates at study endpoint. The clinical evidence that drugs inhibiting serotonin and norepinephrine reuptake (SNRIs) are particularly effective in treating the short, medium and long-term generalized anxiety disorder has recently found an experimental correlate at the neurochemical level. The ability of SNRIs to act simultaneously and more selectively on the serotonergic and noradrenergic transmission is certainly a peculiar property, fundamental in allowing these drugs to modulate the most efficient synthesis of trophic factors and the process of neurogenesis, the two most important phenomena associated functionally to neuroplasticity.