There has been considerable interest internationally in the assessment and treatment of individuals who have a severe personality disorder and who might pose a high-risk of future recidivism. In the United Kingdom, the ‘Dangerous and Severe Personality Disorder’ (DSPD) programme was initiated to deal with just this group. It is important, however, that the DSPD service is filling a treatment void and not competing with already well-established and effective services for (non-DPSD) personality disordered patients. Objective: To establish whether those admitted to innovative DSPD services are different from those admitted to conventional personality disorder (PD) services.

To compare patients admitted to DSPD services with those admitted to personality disordered (non-DPSD) services.

Sixty patients admitted to DSPD services, under DSPD criteria, were compared with 44 patients admitted to personality disordered (non-DSPD) services within the same high secure psychiatric hospital, on risk measures, including

1. (1) an index of predicted future violence

2. (2) previous offending behaviour and

3. (3) pre-treatment levels of institutional risk-related behaviour.

DSPD patients do pose a greater clinical and management risk, have a higher number of pre-treatment risk-related behaviour, and have a greater number of convictions and imprisonments after age 18, relative to PD patients.

The findings broadly confirm the hypotheses as to the higher risk in DSPD patients and thus offer support for the main purpose of DSPD services: to provide treatment for those who represent the highest priority in terms of treatment need and risk to public protection. Implications are discussed.