The Iowa Gambling Task in depression – what have we learned about sub-optimal decision-making strategies?

Abstract

Our earlier study found patients with depression to show a preference for larger reward as measured by the Iowa Gambling Task (IGT). In this IGT version, larger rewards were associated with even larger consequent losses. In the light of the clinical markers defining depressive disorder, this finding might appear controversial at first. Performance of depressed patients on various decision-making (DM) tasks is typically found to be impaired. Evidence points toward reduced reward learning, as well as the difficulty to shift strategy and integrate environmental changes into DM contingencies. This results in an impaired ability to modulate behavior as a function of reward, or punishment, respectively. Clinical symptoms of the disorder, the genetic profile, as well as personality traits might also influence DM strategies. More severe depression increased sensitivity to immediate large punishment, thus predicting future decisions, and was also associated with higher harm avoidance. Anhedonic features diminished reward learning abilities to a greater extent, even predicting clinical outcome. Several questions about how these aspects relate remain to be clarified. Is there a genetic predisposition for the DM impairment preceding mood symptoms? Is it the consequence of clinical signs or even learned behavior serving as a coping strategy? Are patients prone to develop an aversion of loss or are they unable to sense or deal with reward or the preference of reward? Does the DM deficit normalize or is a persisting impairment predictor for clinical outcome or relapse risk? To what extent is it influenced by medication effects? How does a long-lasting DM deficit affect daily life and social interactions? Strikingly, research evidence indicates that depressed patients tend to behave less deceptive and more self-focused, resulting in impaired social DM. The difficulty in daily interpersonal interactions might contribute to social isolation, further intensifying depressive symptoms.

Reduced Dopamine Transporter Functioning Induces High-Reward Risk-Preference Consistent with Bipolar Disorder

“…Manic BD patients are hypersensitive to rewards (Cassidy et al, 1998). Schizophrenia patients exhibit disrupted contingency learning (Brambilla et al, 2012), whereas depressed patients are more sensitive to punishment (Adida et al, 2011;Must et al, 2013). Collectively, these findings support differing mechanisms underlying poor decision making in these disorders.…”

Mechanisms Underlying Motivational Deficits in Psychopathology: Similarities and Differences in Depression and Schizophrenia

“…In depression, there is also evidence for impaired performance on the Iowa Gambling Task (Must et al 2006(Must et al , 2013Cella et al 2010;Han et al 2012), though with some studies not finding impairment (Westheide et al 2007;Smoski et al 2008). There is also evidence of impairments in reversal learning in depression (Murphy et al 2003;Robinson et al 2012;Hall et al 2014).…”

Adaptation and validation of the Melbourne Decision Making Questionnaire to Brazilian Portuguese

“…It is a necessary ability for adequate functioning, and is often impaired in patients with psychiatric disorders such as schizophrenia, 1 obsessive-compulsive disorder, 2,3 bipolar disorder (BD) 4 and depression, 5 and neurological disorders such as multiple sclerosis 6 and traumatic brain injury. 7 Recent studies have also identified it as a significant predictor of clinical outcomes such as treatment dropout and relapse in substance disorders 8,9 and future substance use in patients with BD.…”

“…14,15 Most investigations of DM impairment, especially in psychiatric populations, rely on instruments designed for performance measurement, such as the Iowa Gambling Task (IGT), 16 a computerized instrument which evaluates DM under uncertainty or risk in a simulated card game. This task has been used to study DM impairments in BD, 17 major depressive disorder (MDD), 5 schizophrenia, 1 and obsessive-compulsive disorder. 18 Although these studies have made important contributions to the literature, additional measures of DM could complement these findings and perhaps address some of the limitations associated with the use of the IGT.…”