How effective is psychodynamic therapy in treating schizophrenia? (Emphasis on evaluating rather than outlining)

Psychodynamic therapy is used to treat a wide range of patients who suffer from psychological abnormalities. This therapy focusses on uncovering repressed thoughts and emotions in the patients unconsciousness, which are thought to be at the root of many psychological disorders. Gottidenier et al concluded that psychodynamic therapy was an effective treatment for treating schizophrenia. 

Gottidenier et al reviewed 37 studies, covering 2642 patients. Overall, they found that 66% of those recieving psychoanalytic therapy improved after recieving treatment compared to 35% of those who did not recieve psychotherapy. 

However, there are methodological limitations of Gottidenier's study. For example, the relatively small number of studies meant that it was difficult to assess the impact of variables, such as therapist training or experience. In addition, about half of the studies reviewed did not allocate patients randomly to treatment conditions. This is a problem because this introduces a treatment bias that may have possibly have affected the results. 

Furthermore, there have been many other studies which do not compliment the results obtained by Gottidenier et al. For instance, the Schizophrenia Patient Outcome Research Team (PORT) actually found the opposite. They found that some forms of psychodynamic therapy are harmful for patients with schizophrenia.