Effort-Cost Decision-making Among Individuals With Schizophrenia: A Systematic Review and Meta-analysis.

Importance: Motivational impairments in schizophrenia are by definition associated with poor outcome. It is postulated that the reduction of goal-directed behavior arises from abnormal trade-offs between rewards and efforts. Objective: To examine whether schizophrenia is associated with impairments in effort-cost decision-making. Data Sources: For this systematic review and meta-analysis, the PubMed, ScienceDirect, PsycINFO, Embase, and ClinicalTrials.gov databases were searched from inception to July 2022 for studies that investigated effort-cost decision-making in schizophrenia. Search terms included effort, cost, and schizophrenia. Study Selection: Consensual criteria for inclusion were peer-reviewed studies published in English that used a computerized effort-cost decision-making behavioral paradigm and compared individuals with schizophrenia with control individuals. Data Extraction and Synthesis: The Preferred Reporting Items for Systematic Reviews and Meta-analyses reporting guideline was used for abstracting data. Data were extracted independently by 2 authors and then pooled using random-effects sizes and bayesian approaches. Main Outcomes and Measures: The main outcomes were performance on effort-cost decision-making tasks requiring an effort-reward trade-off, measured by Hedges g effect size. Effects of moderators were tested with meta-regressions and subgroup analyses. Results: Twenty studies involving 1503 participants were included: 837 individuals with schizophrenia (541 [64.6%] male; mean [SD] age, 35.89 [6.70] years) and 666 control individuals without schizophrenia (360 [54.1%] male; mean [SD] age, 34.16 [5.92] years). Participants with schizophrenia had significantly reduced willingness to expend effort for rewards compared with controls (k = 20; effect size, 0.43; 95% CI, 0.30-0.56; P < .001; I2 = 33.1%; Q test P = .08). The magnitude of the deficit was significantly greater for high-reward trials. The severity of negative symptoms was negatively associated with effort-cost decision-making (k = 8; effect size, -0.33; 95% CI, -0.50 to -0.15; P < .001), while participants with a high number of negative symptoms had a significantly larger impairment in effort-cost decision-making (k = 5; effect size, 0.47; 95% CI, 0.10-0.84; P = .01). Conclusions and Relevance: In this systematic review and meta-analysis, schizophrenia was associated with deficits in effort allocation as indexed by effort-cost decision-making tasks. Understanding the cognitive and neurobiological mechanisms driving effort allocation impairments may assist in developing novel interventions.

Direct medical cost of bipolar disorder: Insights from the FACE-BD longitudinal cohort.

BACKGROUND: Bipolar disorder (BD) is a severe chronic psychiatric disorder affecting 0.5 to 1% of the population worldwide. To date, most studies have estimated the cost of BD via information sourced from insurance claims with limited information on clinical characteristics and course of BD. The aims of this study are (i) to estimate the direct healthcare cost associated with BD and to identify contributing factors and (ii) to study the evolution of cost during a two-year follow-up period. METHOD: We analyzed a sample of 1116 individuals with BD included in the Advanced Centers of Expertise in Bipolar Disorder cohort. We estimated the direct healthcare cost per year and per patient, and we identified the clinical features of patients with BD associated with higher direct healthcare costs. In a subsample of patients followed up for two years centers of expertise for BD, we studied the evolution of direct healthcare cost. RESULTS: The average cost of bipolar disorder was € 6910 per year and per patient. Clinical features of BD, sociodemographic characteristics, and associated addiction were associated with higher direct healthcare costs. In the subsample of patients followed-up for two years, direct healthcare cost dropped by more than 50%, strongly suggesting the beneficial effect of specialized care organization. LIMITATION: We did not estimate indirect healthcare and intangible costs. CONCLUSION: Our study investigates the cost of BD and its evolution in a deeply phenotyped longitudinal sample. Cost-utility and cost-effectiveness analyses are required to inform resource allocation decisions and to promote innovative healthcare organizations.

An exoskeleton controlled by an epidural wireless brain-machine interface in a tetraplegic patient: a proof-of-concept demonstration.

BACKGROUND: Approximately 20% of traumatic cervical spinal cord injuries result in tetraplegia. Neuroprosthetics are being developed to manage this condition and thus improve the lives of patients. We aimed to test the feasibility of a semi-invasive technique that uses brain signals to drive an exoskeleton. METHODS: We recruited two participants at Clinatec research centre, associated with Grenoble University Hospital, Grenoble, France, into our ongoing clinical trial. Inclusion criteria were age 18-45 years, stability of neurological deficits, a need for additional mobility expressed by the patient, ambulatory or hospitalised monitoring, registration in the French social security system, and signed informed consent. The exclusion criteria were previous brain surgery, anticoagulant treatments, neuropsychological sequelae, depression, substance dependence or misuse, and contraindications to magnetoencephalography (MEG), EEG, or MRI. One participant was excluded because of a technical problem with the implants. The remaining participant was a 28-year-old man, who had tetraplegia following a C4-C5 spinal cord injury. Two bilateral wireless epidural recorders, each with 64 electrodes, were implanted over the upper limb sensorimotor areas of the brain. Epidural electrocorticographic (ECoG) signals were processed online by an adaptive decoding algorithm to send commands to effectors (virtual avatar or exoskeleton). Throughout the 24 months of the study, the patient did various mental tasks to progressively increase the number of degrees of freedom. FINDINGS: Between June 12, 2017, and July 21, 2019, the patient cortically controlled a programme that simulated walking and made bimanual, multi-joint, upper-limb movements with eight degrees of freedom during various reach-and-touch tasks and wrist rotations, using a virtual avatar at home (64·0% [SD 5·1] success) or an exoskeleton in the laboratory (70·9% [11·6] success). Compared with microelectrodes, epidural ECoG is semi-invasive and has similar efficiency. The decoding models were reusable for up to approximately 7 weeks without recalibration. INTERPRETATION: These results showed long-term (24-month) activation of a four-limb neuroprosthetic exoskeleton by a complete brain-machine interface system using continuous, online epidural ECoG to decode brain activity in a tetraplegic patient. Up to eight degrees of freedom could be simultaneously controlled using a unique model, which was reusable without recalibration for up to about 7 weeks. FUNDING: French Atomic Energy Commission, French Ministry of Health, Edmond J Safra Philanthropic Foundation, Fondation Motrice, Fondation Nanosciences, Institut Carnot, Fonds de Dotation Clinatec.

Reconsideration of the factorial structure of the Barratt Impulsiveness Scale (BIS-11): Assessment of impulsivity in a large population of euthymic bipolar patients.

BACKGROUND: Impulsivity is commonly assessed using the Barratt Impulsiveness Scale (BIS-11). Some studies challenged the reliability of its three dimensional structure and proposed a bi-dimensional structure. METHODS: The psychometric reliability of the BIS-11 scale was studied in a sample of 580 euthymic bipolar patients. An alternative structure of the scale was conceived, using confirmatory factorial analysis (CFA) in the first half (N = 290) and cross-validated in the second half of our sample. Associations between the newly defined shortened scale and predefined clinical variables were computed. RESULTS: The original three dimensional structure did not fit in our sample according to statistical criteria in CFA. A 12 items Impulsivity Scale (IS-12) was designed with strong indices of fitting in the first half of our sample and replicated in the second half of our sample. The IS-12 evidences two dimensions: "behavioral impulsivity" and "cognitive impulsivity". Associations between "behavioral impulsivity" and both presence of past suicide attempts and number of suicide attempts were observed. Substance misuse was strongly associated with both subscores of the new scale. LIMITATIONS: The rating of the items assessing the two dimensions of the IS-12 is reversed. The population is restricted to euthymic bipolar patients. CONCLUSIONS: The Impulsivity Scale assesses two distinct dimensions named behavioral and cognitive impulsivity. It was reliable and valid in our sample and associated with the existence of suicidal behavior and with substance misuse (alcohol and cannabis). Further studies are needed to demonstrate its predictive validity.