How size matters: exploring the association between quality of mental health services and catchment area size.

Significant positive correlations were found between size of catchment area population and diversity of residential, outpatient and voluntary services, indicating that these services concentrate on areas with larger population bases. The third sector seems to significantly complement the public sector in providing different services. Thus the third sector be needs to be functionally integrated with other MHS services to achieve a diversified and integrated service system.