[Effectiveness of Integrated Psychological Therapy for schizophrenia patients : A meta-analysis including 28 independent studies.]

Over the past 24 years, research groups in eight different countries have conducted 28 independent evaluation studies on Integrated Psychological Therapy (IPT) including 1,329 schizophrenia patients. The present study examines the effectiveness of IPT under different treatment conditions by means of a meta-analytic review. The most salient results indicate favourable mean effect sizes for IPT in comparison to control groups (placebo-attention conditions, standard care). Moreover, the superiority of IPT continues to increase during an average catamnestic phase of 8.1 months. The method obtains similarly favourable effects in different functional areas (neurocognition, social behaviour, psychopathology) and different assessment formats (expert ratings, self-reports, psychological tests). The comparison of different settings of IPT and control groups shows the superiority of IPT in any given therapy or site condition. The analysis of subsamples of inpatients, outpatients, and patients in varying rehabilitation phases reveals similarly favourable effects. Comparing only high-quality studies yields comparable results. In summary, the present meta-analysis corroborates evidence that IPT is an 'empirically validated treatment' according to American Psychiatric Association guidelines.