Background: Insufficient evidence exists for a viable choice between long- and short-term psychotherapies in the treatment of psychiatric disorders. The present trial compares the effectiveness of one long-term therapy and two short-term therapies in the treatment of mood and anxiety disorders.
Method: In the Helsinki Psychotherapy Study, 326 out-patients with mood (84.7%) or anxiety disorder (43.6%) were randomly assigned to three treatment groups (long-term psychodynamic psychotherapy, short-term psychodynamic psychotherapy, and solution-focused therapy) and were followed up for 3 years from start of treatment. Primary outcome measures were depressive symptoms measured by self-report Beck Depression Inventory (BDI) and observer-rated Hamilton Depression Rating Scale (HAMD), and anxiety symptoms measured by self-report Symptom Check List Anxiety Scale (SCL-90-Anx) and observer-rated Hamilton Anxiety Rating Scale (HAMA).
Results: A statistically significant reduction of symptoms was noted for BDI (51%), HAMD (36%), SCL-90-Anx (41%) and HAMA (38%) during the 3-year follow-up. Short-term psychodynamic psychotherapy was more effective than long-term psychodynamic psychotherapy during the first year, showing 15-27% lower scores for the four outcome measures. During the second year of follow-up no significant differences were found between the short-term and long-term therapies, and after 3 years of follow-up long-term psychodynamic psychotherapy was more effective with 14-37% lower scores for the outcome variables. No statistically significant differences were found in the effectiveness of the short-term therapies.
Conclusions: Short-term therapies produce benefits more quickly than long-term psychodynamic psychotherapy but in the long run long-term psychodynamic psychotherapy is superior to short-term therapies. However, more research is needed to determine which patients should be given long-term psychotherapy for the treatment of mood or anxiety disorders.