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

Abstract

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% confidence interval (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 to −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 to 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,R2100%,p= 0.01). Those taking first-generation (k= 6,N= 305,g= −0.17, 95% CI −0.40 to 0.06,p= 0.147) or low-dose antipsychotics (k= 5,N= 442,g= −0.19, 95% CI −0.44 to 0.06,p= 0.139) had unimpaired decision-making. Although meta-regression found no linear association between dose and performance, non-reporting of the dose was common and associated with larger impairments (k= 46,Q= 4.71,R214%,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.

A meta-review of literature reviews assessing the capacity of patients with severe mental disorders to make decisions about their healthcare

“…The number of studies included in each review apprised varied between 7 [18,20] and 63 [16], and the number of patients with a mental disorder ranged from 6 [13] to 2483 [15]. Schizophrenia or schizoaffective disorders [12,13,19,20] and psychosis [14,18,21] were the most frequently explored mental illnesses. The general healthy population or patients with a non-mental disorder were the usual study comparators.…”

“…The capacity of mental illness patients for making valuebased decisions was explored in literature reviews of studies based on gambling tasks and on preferences for medication-associated outcomes methods. A systematic review and meta-analysis explored the factors which may help or hinder the ability to make risk-reward decision making in a pooled sample of 4264 individuals with psychosis, based on their performance on the Iowa Gambling Tasks (IGT) and the Cambridge Gambling Tasks (CGT) [21,23,24]. Compared with healthy individuals, people with psychosis had moderately impaired risk-reward decision-making ability (g = − 0.57, 95% CI − 0.66 to − 0.48; I 2 45%; moderate quality) [21].…”

Polygenic Risk Scores for Psychiatric Disorders Reveal Novel Clues About the Genetics of Disordered Gambling

“…Relative to healthy controls, individuals with DG (Kovács, et al, 2017) and SCZ (Betz, et al, 2019;Woodrow, et al, 2018) exhibit impaired decision-making abilities on the Iowa Gambling Task (IGT; Bechara, et al, 1994). The IGT is a complex task that taps a multifaceted construct, and can reflect effects originating in a number of neural systems related to bottom-up impulsive processes and top-down reflective impulse control (Bechara, 2005;Buelow & Suhr, 2009).…”

Evidence on the capacity of severe mental disorder patients to make well-founded decisions about their healthcare: a meta-review

“…The MacArthur Competence Assessment Tool for Treatment (MacCAT-T) was the primary assessment instrument in eight reviews, while two reviews used the Iowa or Canada Gambling Tasks to assess capacity to make decisions. Nine of the reviews included in the present report were conducted by authors in European countries (12) (15) (17) (19)(20)(21)(22)(23)(24), two were based in the United States (14) (18), one study was conducted in Australia (16), and another in several countries (13) (Table 4).…”

“…A systematic review and meta-analysis explored the factors which may help or hinder the ability to make risk-reward decision making in a pooled sample of 4,264 individuals with psychosis, based on their performance on the IGT and the CGT. Compared with healthy individuals, people with psychosis had moderately impaired risk-reward decision-making ability (g =-0.57, 95% CI -0.66 to -0.48; I 2 45%; moderate quality) (23). They were also more likely to value rewards over losses (k = 6, N = 516, g = 0.38, 95% CI: 0.05 to 0.70, I 2 64%), and to base decisions on recent rather than past outcomes (k = 6, N =516, g = 0.30, 95% CI: -0.04 to 0.65, I 2 68%).…”