Objective: To update evidence from studies on family intervention in schizophrenia looking carefully at methodological issues.
Method: Twenty-five studies were reviewed, using specific outcome criteria, and computing effect sizes whenever possible.
Results: Effect on relapse is relatively well assessed, although differences emerged particularly in comparison with poor control treatments and disappeared in recent studies. Findings on patient's symptoms, social functioning or family variables are limited and affected by methodological pitfalls. No difference between intervention models emerged, although behavioural/psycho-educational approaches were better investigated. Patients' inclusion, greater frequency and length of treatment led to better results. The main flaws were: poor control of standard treatment, small sample sizes, failure in evaluating clinical significance in continuous outcome variables.
Conclusion: It remains unclear whether the effect depends on family treatment or on more intensive care. The failure to relate outcome to family-mediating variables is a challenge to the rationale underlying family interventions.