Patients with major depression show greater memory improvement if motivation is increased: An exploratory study under real-life-like conditions

Abstract

ABSTRACTIntroduction: Loss of motivation is a core feature of major depression (MDD) and has been suggested to influence neuropsychological performance. However, previous studies have come to inconsistent results, but they were only done under laboratory test conditions. Thus, the aim of the present study is to experimentally investigate the influence of motivation on neurocognition under real-life-like conditions.Methods: Twenty-two inpatients with MDD (M = 42.5 years) and 27 demographically comparable healthy control subjects (HC) underwent a new memory paradigm under real-life-like conditions: To bridge the “waiting time” before a planned neuropsychological assessment, subjects were shown two videos on the waiting room TV with different motivational appeals. Video 1 (lower motivation) deals with factual information about the research department’s history. Video 2 (higher motivation) consists of information about a current lottery. The video stories were developed by analogy to the established “Logical Memory” test. Subjective motivation was assessed by a short form of the Intrinsic Motivation Inventory. After 30 min, subjects had to perform an unexpected free recall and recognition of the video content during the intended test session.Results: MDD patients, different from HC subjects, rated their intrinsic motivation for the presentation of video 2 as higher compared to video 1. Two-way repeated measures analyses of variance as well as post-hoc tests showed a significant effect of motivation on the MDD patients' memory scores for video 2.Conclusions: The results provide support for an association between motivation and neurocognition in depressed patients and suggest that cognition under real-life-like conditions can be improved more in MDD patients relative to healthy controls with the use of motivational interventions.