An outline is presented of four characteristically different types of partial hospitalization programs (p.h.p.) currently operating in The Netherlands. The findings are based on empirical data gathered from a study of 85 institutions active in this particular field. The institutions are distinguished according to the function they perform within the total mental health care system, the assumption being that the p.h. programs are capable of fulfilling four main functions:

1. as an alternative to full-time hospitalization;

2. as a transition from full-time hospitalization;

3. as an alternative to ambulatory treatment;

4. as a day-care or rehabilitation service for the chronically mentally ill.

A study has been made of the differences and similarities between four types of institution specializing in one of the four functions mentioned above. In this connection, the authors have concentrated in particular on staffing, number of places, accommodation, organization, referral, patient population (age, education, diagnoses), treatment (type, duration, drug use) and contra-indications.