Background: Drug-resistance for depression and anxiety is a major limitation in the treatment of these common disorders, and adjunct support interventions may be beneficial in the treatment of these patients. Aims: The purpose of this study was to evaluate the effects of a short-term (8 session) Relaxation Response Skills Training (RRST) programme for a population of psychiatric outpatients with anxiety and mood disorders who were unresponsive to drug treatment, and to test the feasibility of this intervention as complementary treatment for a psychiatric setting. Method: Forty patients were measured for overall psychopathological symptoms, depression, and anxiety, and were then given an 8-week course of RRST, while continuing their pharmacological treatment. Following the RRST intervention, participants were again assessed. Results: The results demonstrated reductions in overall symptoms (large effect size and reasonable clinically significant change), and also in depression and anxiety (medium effect sizes and clinically significant change). Conclusions: These results suggest that this short-term RRT offers a simple and cost-effective way to augment drug management for participants with common psychiatric disorders who are less responsive to the drug treatment.