title: Why don't you try harder? An investigation of effort production in major depression.
abstract: Depression is mainly characterized as an emotional disorder, associated with reduced approach behavior. It remains unclear whether the difficulty in energising behavior relates to abnormal emotional states or to a flattened response to potential rewards, as suggested by several neuroimaging studies. Here, we aimed to demonstrate a specific incentive motivation deficit in major depression, independent of patients' emotional state. We employed a behavioral paradigm designed to measure physical effort in response to both emotional modulation and incentive motivation. Patients did exert more effort following emotionally arousing pictures (whether positive or negative) but not for higher monetary incentives, contrary to healthy controls. These results show that emotional and motivational sources of effort production are dissociable in pathological conditions. In addition, patients' ratings of perceived effort increased for high incentives, whereas controls' ratings were decreased. Thus, depressed patients objectively behave as if they do not want to gain larger rewards, but subjectively feel that they try harder. We suggest that incentive motivation impairment is a core deficit of major depression, which may render everyday tasks abnormally effortful for patients.
authors.affiliation: Motivation, Brain and Behavior lab, Institut du Cerveau et de la Moelle épinière, Hôpital de la Pitié-Salpêtrière, Paris, France.
authors.forename: Marie-Laure
authors.initials: ML
authors.lastname: Cléry-Melin
authors.forename: Liane
authors.initials: L
authors.lastname: Schmidt
authors.forename: Gilles
authors.initials: G
authors.lastname: Lafargue
authors.forename: Nicolas
authors.initials: N
authors.lastname: Baup
authors.forename: Philippe
authors.initials: P
authors.lastname: Fossati
authors.forename: Mathias
authors.initials: M
authors.lastname: Pessiglione
mesh_terms: D000328:Adult; D001519:Behavior; D003710:Demography; D003865:Major Depressive Disorder / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D009042:Motivation