Engagement in a medium secure personality disorder service: a comparative study of psychological functioning and offending outcomes.

BACKGROUND: Specialist treatment programmes for personality disordered offenders suffer from high rates of non-completion. This has important consequences for service providers and individual patients.
METHOD: Data from hospital records and the Offenders Index were compared for groups of treatment completers (n = 22) and non-completers (n = 59) discharged from a specialist treatment programme.
RESULTS: Twenty-seven percent of patients completed treatment, 37% were expelled for rule breaking and 35% disengaged early from treatment. Psychometric assessments of anger expression and anxiety showed no differences between the groups, however, treatment completers showed lower levels of impulsivity and psychopathy than either of the non-completer groups. Rates of post-discharge offending for grave and standard list offences were 56.8 and 10.8%, respectively.
CONCLUSIONS: Despite careful selection methods, a large proportion of personality-disordered patients admitted to specialist units failed to complete treatment. Psychometric assessments of anger expression, anxiety and impulsivity showed limited utility in differentiating treatment completers and non-completers. Sample size limitations in this naturalistic follow-up impacted on the interpretation of differences observed between the groups on the primary outcome measure of re-offending after discharge.