Effort-Based Decision-Making Paradigms for Clinical Trials in Schizophrenia: Part 1—Psychometric Characteristics of 5 Paradigms

Abstract

Impairments in willingness to exert effort contribute to the motivational deficits characteristic of the negative symptoms of schizophrenia. The current study evaluated the psychometric properties of 5 new or adapted paradigms to determine their suitability for use in clinical trials of schizophrenia. This study included 94 clinically stable participants with schizophrenia and 40 healthy controls. The effort-based decision-making battery was administered twice to the schizophrenia group (baseline, 4-week retest) and once to the control group. The 5 paradigms included 1 that assesses cognitive effort, 1 perceptual effort, and 3 that assess physical effort. Each paradigm was evaluated on (1) patient vs healthy control group differences, (2) testretest reliability, (3) utility as a repeated measure (ie, practice effects), and (4) tolerability. The 5 paradigms showed varying psychometric strengths and weaknesses. The Effort Expenditure for Rewards Task showed the best reliability and utility as a repeated measure, while the Grip Effort Task had significant patient-control group differences, and superior tolerability and administration duration. The other paradigms showed weaker psychometric characteristics in their current forms. These findings highlight challenges in adapting effort and motivation paradigms for use in clinical trials.

Inflammation Effects on Motivation and Motor Activity: Role of Dopamine

“…Interestingly, although some studies have detected an overall decrease in effort expenditure (Hartmann et al, 2015;McCarthy et al, 2016;Wolf et al, 2014), the most consistent group differences observed across studies have implicated deficits in effort allocation rather than effort expenditure (Barch et al, 2014;Gold et al, 2013;Horan et al, 2015;Reddy et al, 2015). That is, schizophrenia patients may not choose to expend less effort overall, but they appear to be significantly less sensitive to reward-related information when choosing when to expend effort.…”

“…In schizophrenia, an even greater number of studies have found evidence for effort-related abnormalities using a variety of effort-tasks (Barch et al, 2014;Fervaha et al, 2013;Gold et al, 2013;Hartmann et al, 2015;McCarthy et al, 2016;Reddy et al, 2015;Strauss et al, 2016). Interestingly, although some studies have detected an overall decrease in effort expenditure (Hartmann et al, 2015;McCarthy et al, 2016;Wolf et al, 2014), the most consistent group differences observed across studies have implicated deficits in effort allocation rather than effort expenditure (Barch et al, 2014;Gold et al, 2013;Horan et al, 2015;Reddy et al, 2015).…”

“…Several studies reported relationships with between reduced effort and negative symptoms (Hartmann et al, 2015;Strauss et al, 2016;Wolf et al, 2014), whereas others found that the strongest relationships were between measures of poor effort allocation and negative symptoms (Barch et al, 2014;Reddy et al, 2015). Still other studies found that greater negative symptoms severity as assessed by clinical interview measures such as the Clinical Assessment Interview for Negative Systems (CAINS; Kring et al, 2013) was associated with greater effort expenditure (McCarthy et al, 2016).…”

Translational Rodent Paradigms to Investigate Neuromechanisms Underlying Behaviors Relevant to Amotivation and Altered Reward Processing in Schizophrenia

“…This cognitive effort task has been reverse translated for use in humans and is described in detail as a perceptual effort task elsewhere in this issue. 47,48 Although largely consistent with the rodent task, the difficulty level for patients was titrated based on the patients' baseline abilities. Future studies will be required to demonstrate the cross-species validity of findings for this task.…”

Inefficient effort allocation and negative symptoms in individuals with schizophrenia

“…In understanding these motivational deficits it is useful to consider that acting on motivation by allocating effort requires a cost-benefit assessment of task difficulty and reward magnitude (Gendolla and Krüsken, 2002). Individuals with schizophrenia have demonstrated reduced effort allocation or impaired effort-cost computations (Gold et al, 2013) in laboratory tasks such that, compared to healthy controls, they are less likely to choose high-effort options when probability or magnitude of reward is increasing (Barch et al, 2014; Fervaha et al, 2013; Gold et al, 2013; Reddy et al, 2015; Treadway et al, 2015). These findings suggest that individuals with schizophrenia do not display a complete failure to respond to reward, but that they often have difficulty with anticipatory pleasure and recruiting effort to pursue rewards in trials with the greatest probability of reward or reward magnitude.…”