Decision-making ability in psychosis: a systematic review and meta-analysis of the magnitude, specificity and correlates of impaired performance on the Iowa and Cambridge Gambling Tasks

To identify factors which may help or hinder decision-making ability in people with psychosis, we did a systematic review and meta-analysis of their performance on the Iowa and Cambridge Gambling Tasks. Analysis of 47 samples found they had moderately poorer performance than healthy individuals (N=4264, g=-0.57, 95% CI -0.66 to -0.48). Few studies (k=8) used non-psychotic clinical comparator groups, although very low quality evidence (k=3) found people with bipolar disorder may perform better. Negative symptoms (k=13, N=648, r=-0.17, 95% CI -0.26, -0.07) and lower IQ (k=11, N=525, r= 0.20, 95% CI 0.29, 0.10), but not positive symptoms (k=10, N=512, r=-0.01, 95% CI -0.11, 0.08), each had small-moderate associations with poorer decision-making. Lower quality evidence suggested general symptoms, working memory, social functioning, awareness of emotional responses to information, and attentional bias towards gain are associated with decision-making, but not education, executive functioning or overall symptoms. Meta-regression suggested an inverse association between decision-making and depression severity (k=6, Q=6.41, R2 100%, p=0.01). Those taking first-generation (k=6, N=305, g=-0.17, 95% CI -0.40, 0.06, p=0.147) or low-dose antipsychotics (k=5, N=442, g=-0.19, 95% CI -0.44, 0.06, p=0.139) had unimpaired decision-making. Although meta-regression found no linear association between dose and performance, non-reporting of dose was common and associated with larger impairments (k=46, Q=4.71, R2 14%, p=0.03). Those supporting people with psychosis to make decisions, including treatment decisions, should consider the potential effect of these factors. Interventionist-causal trials are required to test whether reducing antipsychotic dose and treating anxiety and depression can improve decision-making in this group