ABSTRACT
Group therapy still remains one of the less advanced research topics among existing treatments for psychosis. The suitability of nomothetic methods to assess psychosocial interventions, where the subjective components are enormously significant and are often overlooked by quantitative methods used in evidence-based medicine (EBM), is a problem shared by all forms of psychotherapy. The implementation of EBM in medical practice in the 1990s was framed by the concept of 'managed care' and was linked to randomised clinical trial (RCT) as a methodological tool. The reviewed RCT studies were grounded in four main techniques: social skills training (SST), cognitive behaviour therapy (CBT), psychoeducational therapy (PE) and integrated psychological therapy (IPT). Reviewed CBT trials got the best scores on the Jadad scale, followed by SST, IPT and PE. CBT achieved the best scores in the Jadad scale, which is congruent with the facts that its context is well structured and generally shorter, with all variables controlled, and that it uses small samples.
