Treating depression is rarely straightforward, but treating someone who is depressed and also has comorbid personality disorders can be even more complicated.

Studies have shown that short-term psychodynamic psychotherapy (STPP) is a treatment worth considering for depression and personality disorders when they occur individually, but this intervention has not yet been studied systematically for people with comorbid depression and personality disorders. This systematic review with meta analysis set out to provide a reliable answer to this question.

The strength of the evidence they found and the limitations of the study itself did not provide a conclusive answer, but they have been able to show that STPP is a treatment that warrants further investigation.

The review consists of data from patients meeting the criteria for both depressive disorders and personality disorders, this includes 8 randomised controlled trials (6 with major depression and 2 with minor depression) with 166 participants receiving STPP in total. So the numbers are small and the quality of the studies is only moderate.

The authors compared the STPP pre- to post-treatment depression change in 6 studies, totalling 141 subjects:

• The mean pooled effect size was 1.13 (95% CI:0.87–1.39)
• The effect size was 1.34 for all measures of depression (95% CI: 0.95–1.73).
• Mean effect sizes for general psychopathology and measures of interpersonal functioning were 1.00 (95% CI: 0.67-1.33) and 1.27 (95% CI: 0.76-1.79), respectively.

The researchers concluded:

STPP is a brief psychotherapeutic intervention with a modest evidence base to support its consideration in major depression with personality disorders (PD). It lacks significant adverse effects, side effects, and toxicities, as well as the adverse effects of somatic treatments.

Further research is warranted into the specific mechanisms of action, magnitude of effects and limitations of utility of this method. However, within the limits of this study, our findings suggest that STPP warrants consideration as a first line treatment option for comorbid PD and major depression.

Abbass A, Town J, Driessen E. The efficacy of short-term psychodynamic psychotherapy for depressive disorders with comorbid personality disorder (PDF). Psychiatry. 2011 Spring;74(1):58-71.