Impact of Clozapine versus Haloperidol on Conditional Release Time and Rates of Revocation in a Forensic Psychiatric Population

Abstract

Background Clozapine remains the cornerstone of treatment for treatment refractory schizophrenia. Clozapine has been shown to improve quality of life and cognitive functioning and to reduce hospital days in psychiatric patients. The impact of clozapine in a forensic population of psychiatric patients has not been studied. Methods This study is a naturalistic, retrospective database analysis of forensic patients hospitalized at the Northwest Missouri Psychiatric Rehabilitation Center from January 1, 1990 to August 1, 1999 who were treated with clozapine or haloperidol. Patients were either court ordered for hospitalization as having been found not guilty by reason of insanity or as incompetent to proceed to trial. Results Data from 84 patients (69 male, 15 female) were included in the analysis. The primary Axis I diagnoses were substance abuse (n = 61) and schizophrenia (n = 46). Patients had been treated with haloperidol (n = 78) and clozapine (n = 21), and some had received each agent as monotherapy during their course of treatment (n = 15). Assault (n = 22), armed criminal action (n = 18), and burglary (n = 18) were the primary forensic reasons for admission. Of those eligible to obtain a conditional release, 33% of haloperidol-treated patients and 38% of clozapine-treated patients obtained their conditional release on those medications. Haloperidol-treated patients were more likely to have their conditional release revoked (58.8%) versus those treated with clozapine (0%). Clozapine-treated patients were also more likely to stay on conditional release for longer periods of time. Global Assessment of Functioning (GAF) scores improved in both treatment groups; however, of 15 patients converted from haloperidol to clozapine, 93% (n = 14) saw improvements in GAP scores. Conclusions Clozapine and haloperidol effectively reduce psychosis and aggression. In our study, clozapine-treated patients were more likely to obtain a conditional release and stayed on conditional release for longer periods of time. Although the need exists to study this patient population more closely from a longitudinal standpoint, one may suspect that these findings represent a potential decrease in healthcare costs for the treatment of forensic psychiatric patients.

A systematic review of the evidence of clozapine's anti-aggressive effects

“…Others have found that violent incidents decreased (Wilson, 1992) as did bed days after 1.5 yr of clozapine treatment (Reid et al 1994), the advantage increasing year on year with continued treatment, while there was again little or no effect on psychotic symptoms (Gelly et al 1997). Stoner et al (2002) found that those on clozapine were more likely to achieve a conditional release and to stay out of hospital on release for longer, while both aggression and anxiety were decreased with clozapine treatment in a central mental hospital in Finland (Rimon et al 1994), with 37 % being discharged at 12 months.…”

Pharmacological Treatment in Forensic Psychiatry—A Systematic Review

“…The primary reasons for exclusion of studies were that the studied populations were not treated within a forensic setting or the studies did not evaluate the effect of an intervention (list of excluded full-text studies with reasons for exclusion are available on request). All 10 included studies (22)(23)(24)(25)(26)(27)(28)(29)(30)(31) were assessed as having a high risk of bias, primarily due to selection bias. The review process and number of reviewed articles are summarized in the flow diagram in Figure 1.…”

“…The 10 included studies, which are further described in Table 1, were conducted in the United Kingdom (24,25,30,31), USA (23,29), and Canada (22,(26)(27)(28). Seven of the studies were retrospective.…”

“…One study followed the patients from in-to outpatient care (28). Half of the studies investigated the specific anti-psychotic clozapine with regard to effect on aggressive behavior, psychotic symptoms, time of treatment inside the hospital before release and time outside the hospital before readmission (22,25,(28)(29)(30).…”

“…In one study there were three groups with mood stabilizers, which found reduction on psychotic symptoms in the group with valproate and the combination valproate and topiramate after treatment (27). When studying crime-free time and time in the community between discharge from hospital to reoffending or readmission, two studies showed valuable effects in the clozapine group (28,29) compared to other antipsychotics. Regarding measures of time spent in hospital after the start of treatment, two studies showed positive effects of clozapine (29,30), while a third study did not find any differences between clozapine and other antipsychotics (25).…”