Cognitive-Behavioral Therapy for Obsessive-Compulsive Disorder as a Comorbidity with Schizophrenia or Schizoaffective Disorder

of OCD was 6.8 years (range 1–16.7). The temporal onset of OCD was subsequent to SCH/SA in 11 patients (6 SCH, 5 SA), anterior in 3 SA patients and concomitant in 7 patients (3 SCH, 4 SA). Four patients presented at least one other Axis I lifetime comorbid disorder. Pharmacological treatments for SCH/SA were chosen by the first author (A.T.) based on the patient’s clinical condition, and follow-up visits were scheduled as required, ranging from every week to every few months. CBT was conducted by 4 cognitivebehavioral psychologists with 6 5 years of experience in treating OCD. CBT consisted of imaginal and in vivo exposure, ritual prevention and/or delay, cognitive therapy and other ad hoc intervention used to supplement exposure and ritual prevention strategies. Patients were treated in a naturalistic setting, in the sense that manualized guidelines [33] were adapted to each patient after careful consideration of their level of insight, treatment adherence and Axis I comorbidity. Therapy sessions were scheduled flexibly and jointly by the therapist and patient. Patients received an average of 4 sessions per month during the first 4 months and then continued therapy with 1–4 sessions per month. CBT duration was not determined in advance. We provided a mean of 34.3 h of therapy (range 23–41) to patients with SA and 31.1 h (range 8–40) to patients with SCH, excluding 1 patient who participated in a single session before withdrawing from the study. Obsessive-compulsive symptoms were assessed using the Y-BOCS. The clinical severity of illness was assessed using the Clinical Global Impressions-Severity (CGI-S) scale [34] and overall functioning using the Global Assessment of Functioning scale [35] . Scales were administered at baseline (T0) and after 6 (T1) and 12 months (T2) of CBT. The Clinical Global Impressions-Improvement (CGI-I) scale [34] was used to evaluate improvement at T1 and T2. Schizophrenic and schizoaffective symptoms at T0 were assessed using the Positive and Negative Symptoms Scale. All assessments were conducted by the first author, who was not involved in the CBT. The primary outcomes were adherence rate (percentage of completers) and remission rate (Y-BOCS total score ! 16). Secondary outcomes were treatment response, defined as a decrease in the Y-BOCS total score from baseline to T2 6 25%, and a CGI-I score ̂ 2. One patient with SCH discontinued CBT after 1 session; 1 patient with SCH discontinued before T1 and 3 patients (1 SCH, 2 SA) before T2. Of these, 3 reported that CBT was ineffective and 1 was hospitalized for an episode of psychotic exacerbation. The remaining 16 patients were still receiving CBT at T2. Table 1 shows the results of repeated-measures ANOVA for Y-BOCS and the CGI-S and the Global Assessment of Functioning scales. All outcome measures showed statistically significant improvements at 6 months and slower improvement afterwards. There was no differential change over time in SA versus SCH, except for a significantly greater functional improvement in SA from T0 to T1. At T2, 52% of patients (11/21) were rated as ‘much/ The co-occurrence of obsessive-compulsive disorder (OCD) in patients with schizophrenia (SCH) or schizoaffective disorder (SA) is quite common (7.8–25%) [1–6] . Obsessive-compulsive symptoms in patients with SCH are associated with severe psychosis, a high risk of suicide, severe impairment of social behavior and a poor prognosis [7–12] . Despite the high prevalence and disabling effects of OCD-SCH/SA comorbidity, only a few studies have investigated treatment strategies for this difficult-to-treat condition. The best current available treatments for noncomorbid OCD are serotonin reuptake inhibitors (SRIs) and cognitive-behavioral therapy (CBT) incorporating exposure and ritual prevention [13] . The American Psychiatric Association guidelines [13] and Poyurovsky et al. [14] suggest treating OCD co-occurring with SCH by combining either typical or atypical antipsychotics with SRIs. However, evidence on the beneficial effect of these combinations is inconclusive [15–27] . Furthermore, an antipsychotic-SRI combination could produce a clinically significant pharmacokinetic drug interaction. Hence, alternative therapeutic approaches for OCD-SCH/SA are needed. The aims of this open naturalistic study were to examine adherence to and the effectiveness of adjunctive CBT for OCD in patients with stabilized SCH/SA. Consecutive patients seen between 1 January 2003 and 1 January 2008 at the ‘Istituto di Psicopatologia’ in Rome were screened for eligibility. Inclusion criteria were as follows: (1) age 18–65 years; (2) meeting DSM-IV criteria for OCD and either SCH or SA as assessed by the Structured Clinical Interview for DSM-IV [28, 29] ; (3) OCD of at least moderate severity [Yale-Brown Obsessive Compulsive Scale (Y-BOCS) [30, 31] total score 6 16], and (4) stabilized SCH or SA, even if symptoms were not entirely absent (Positive and Negative Symptoms Scale [32] total score ̂ 75). The exclusion criterion was the presence of neurological conditions inducing OCD. All patients gave written informed consent for the anonymous use of their clinical records, and a local ethical committee approved the research project. Twenty-one patients (13 males, 8 females) were enrolled; the mean age was 29.3 years (range 18–37). Nine patients (43%) had SCH and 12 (57%) SA. The mean duration Received: December 20, 2010 Accepted after revision: May 17, 2011 Published online: November 25, 2011