During recent decades, there has been a substantial increase in admissions to forensic mental hospitals in several European countries. It is not known if reforms implemented in mental health policies and practices are responsible for this development.

Our study examined the development of mental health care in Austria and the incidence and prevalence of mentally disordered offenders judged not guilty by reason of insanity (NGRI).

We analysed data on service provision and data from criminal statistics between 1970 and 2008 from several national sources.

During the first decade when reforms to mental health practice were implemented, the incidence and prevalence of offenders judged NGRI remained unchanged, despite a reduction of mental hospital beds by nearly 50% and little outpatient care. Surprisingly, the enormous increase in admissions to forensic inpatient treatment began in Austria only after community mental health services were rolled out across the country in the 1990s. This increase was primarily due to admissions of patients who had committed less severe offences, while rates of those who had committed homicide remained unchanged.

Our results cannot be explained by details of the reforms such as the downsizing of mental hospitals or a lack of outpatient facilities, nor by changes to criminal sentencing. Rather, the results provide evidence of an increasingly inadequate provision of comprehensive care for “difficult” but not extremely dangerous psychotic patients living in the community. This may result from the attitudes of mental health professionals who have become less inclined to integrate aggressive behaviour into their understanding of psychosis. As a consequence, increasing numbers of “difficult” patients end up in forensic psychiatric institutions. This development, which can be observed in nearly all European countries, raises concerns with regard to efforts to destigmatize both patients and psychiatry.