The recovery of factors associated with decision-making capacity in individuals with psychosis

Abstract

Background There is limited data on the recovery of factors associated with decisional capacity in patients with psychosis. Aims To study the relationship between changes in mental capacity, symptoms and global functioning using structured measures during treatment for psychosis. Method Fifty-six patients with psychosis were assessed for capacity to consent to treatment on admission and at 6 and 12 weeks following treatment. The MacArthur Competence Assessment Tool – Treatment, the Positive and Negative Symptom Scale and the Global Assessment of Functioning Scale were used to measure mental capacities, symptom severity and global functioning respectively. Treating consultants rated capacity to consent, masked to these measures. Results Greater impairments on all measures were found in patients assessed as lacking capacity. These improved with treatment over 12 weeks with significant effect sizes (0.5 to 0.6). Stronger correlations between mental capacities, positive symptoms (-0.47) and global functioning (0.56) were noted in the first 6 weeks. Conclusions Impairments in capacity in acute stages of psychosis are related to symptom severity and functional impairment. They improve during treatment, particularly in the first 6 weeks.