Therapeutic alliance in antidepressant treatment: cause or effect of symptomatic levels?

Previous studies have shown that in psychotherapy alliance is a predictor of symptomatic change, even while accounting for the temporal precedence between alliance and symptoms. However, the extent to which alliance predicts outcomes in psychopharmacology is yet to be fully investigated considering the fact that alliance can be the result, rather than the cause, of symptomatic change. The current prospective study examined whether the alliance predicts outcomes in psychopharmacology, while controlling for previous symptomatic change throughout the course of treatment.

Data from a psychopharmacological randomized controlled trial for the treatment of adult major depression (n = 42), including the patients' rating of the alliance with the physicians, were analyzed. Multilevel models controlling for autoregressive lag of the dependent variable were used in all analyses to examine the effect of alliance on outcome.

The effect of alliance on outcome, while controlling for prior symptomatic levels, was significant and restricted to the middle phase of treatment (week 4, p = 0.005), when most of the reductions in symptoms were observed. Exploratory analyses of the differences between placebo and medication conditions suggest that the differences between the patients in their average alliance levels predicted a greater reduction in symptoms in the placebo compared to the medication conditions (p = 0.008). The main limitation is the small cohort size.

The findings suggest an effect of alliance on outcome in psychopharmacology, which is not merely the result of previous symptomatic levels. This effect may be more robust in conditions that do not include active treatment (placebo), possibly serving as a compensatory effect.