This clinical trial tests the feasibility, effectiveness and patient satisfaction with cognitive remediation therapy for patients diagnosed with schizophrenia or schizoaffective disorder within a forensic hospital. It is hypothesised that patients receiving cognitive remediation therapy will have an improvement in cognitive performance, real world functioning, symptoms, violence risk and benefit more from additional psychosocial treatment programmes over time relative to patients receiving treatment as usual. Furthermore it is hypothesised that it will be feasible to carry out such a study and that patients will report high rates of satisfaction with cognitive remediation therapy. Finally it is hypothesised that differences on the effectiveness measures will be maintained at 6 month follow up after the end of treatment.

This is a single centre randomised clinical trial to evaluate the feasibility, effectiveness and patient satisfaction with cognitive remediation therapy within a secure forensic setting for patients diagnosed with schizophrenia or schizoaffective disorder.

The feasibility of the intervention will be assessed using key indicators such as rate of enrolment, retention of patients in the trial, blinding effectiveness, and completion rate of the primary outcome measure. The effectiveness of the intervention will be assessed using the MATRICS consensus cognitive battery, symptoms (PANSS and CAINS) and real world functioning (SOFAS: Social and occupational functioning assessment scale). The effect of cognitive remediation on violence risk (HCR-20), programme completion and recovery (Dundrum 3 & 4) will also be examined, where programme completion is a measure of attainments from participating in additional psychosocial interventions and recovery is a measure of stability of mental state.

Patient satisfaction with cognitive remediation therapy will be assessed using a consumer constructed interview developed by Rose et al (2008) and administered by a social worker not involved in the delivery of cognitive remediation.

The trial will take place at the Republic of Ireland's Central Mental Hospital (CMH). The CMH is the only secure forensic psychiatric hospital for the Republic of Ireland, a population of 4.6 million. CMH provides specialised care for adults who have a mental disorder and are at risk of harming themselves or others.

After a baseline assessment to ensure eligibility and to obtain consent, an estimated 60 patients will be randomised to receive fourteen weeks of cognitive remediation versus treatment as usual. Patients who receive treatment as usual will be offered cognitive remediation upon completion of the study. Patients allocated to cognitive remediation will receive three individual sessions of cognitive remediation a week and one group session, fifty-six sessions in total The focus of the group session is to normalise cognitive difficulties that patients may be experiencing, to receive support and to help generalise gains. The primary outcome measure the MATRICS composite score and secondary outcome measures to assess real world functioning, symptoms, violence risk, programme completion and recovery will be administered at baseline, the end of treatment and at six month follow up. Secondary measures will also include feasibility outcomes and patient satisfaction with cognitive remediation therapy. All evaluators of the effectiveness measures will be blind to participant treatment condition at the time of assessment.

The cognitive remediation therapy is a principle driven intervention consisting of nine treatment principles: Principle 1 refers to relationship building, Principle 2 refers to collaborative goal setting, Principle 3 involves the session structure, Principle 4 concerns the content of the sessions, Principle 5, concerns the pacing of sessions, Principle 6 involves scaffolding and errorless learning, Principle 7 refers to meta-cognitive strategies, Principle 8 involves generalisation of gains, finally Principle 9 refers to managing ambivalence. The actual therapy will involve the use of a combination on pen, paper and computerised materials to stimulate patient's cognitive capacity and to provide them with the opportunity to apply meta-cognitive strategies.

The investigators hypothesise that it is feasible to carry out a randomised controlled trial within a single centre forensic setting and that patients will report high rates of satisfaction with cognitive remediation. It is also hypothesised that patients receiving cognitive remediation therapy will have an improvement in cognitive performance (the primary outcome measure), real world functioning, symptoms and violence risk over time relative to patients receiving treatment as usual; specifically that there will be a treatment by time interaction. Furthermore it is hypothesised that these differences will be maintained at six month follow up after the end of treatment.

In addition it is hypothesised that patients receiving cognitive remediation will show an improvement over time on the Dundrum programme completion and recovery scales compared to those receiving treatment as usual.

While meta-analytic reviews have demonstrated that cognitive remediation therapy has a beneficial effect on the cognitive deficits experienced by patients with schizophrenia (Wykes et al 2011), to the best of our knowledge there has been no study with forensic mental health patients. The current study will help answer whether it is feasible to deliver cognitive remediation within a forensic mental health setting and whether it is acceptable to patients. The study aims to contribute to the evidence base for psychological interventions within a forensic setting and to answer the question as to whether cognitive remediation has a beneficial effect and if it does whether this effect is maintained over time.

Inclusion Criteria:

• A Structured Clinical Interview for Diagnostic and Statistical Manual IV (SCID) diagnosis of schizophrenia or schizoaffective disorder.

Exclusion Criteria:

• Acutely psychotic, or judged too dangerous to participate in treatment, or being over 65 years of age.