title: Experimental evidence for a motivational origin of cognitive impairment in major depression.
abstract: BACKGROUND
  Diagnostic criteria and empirical evidence support the existence of cognitive deficits in depression. However, depressed mood, loss of interest and low self-efficacy might influence cognitive performance.
  
  
  METHODS
  Goal-setting instructions were used to promote motivation in depressed patients and control subjects during neuropsychological assessment. The resulting performance was compared with performance using standard instructions. Sixty in-patients with non-psychotic unipolar depression and 60 age- and education-matched healthy control subjects were assessed with standard neuropsychological tests [the Auditory Verbal Learning Test (AVLT), the Digit Symbol Test (DST), the Regensburg Word Fluency Test (RWT), and the Number Combination Test (Zahlen-Verbindungs-Test, ZVT)] using either goal-setting or standard test instructions.
  
  
  RESULTS
  Depressed patients showed lower baseline performance and lower generalized self-efficacy (p<0.0005) than controls. However, goal-setting instructions significantly improved patients' memory performance by 10% [AVLT: F(5, 54)=3.611, p=0.007] and psychomotor performance by 13% [ZVT: F(3, 56)=3.667, p=0.017]. Consequently, patients and control subjects demonstrated similar results when goal-setting instructions were applied. Goal-setting instructions showed a statistical trend, increasing patients' performance in the DST by 12% [F(1, 58)=2.990, p=0.089], although their verbal fluency measured by the RWT did not increase. No significant correlations of increased performance with generalized self-efficacy were found.
  
  
  CONCLUSIONS
  Cognitive deficits in depressed patients are influenced by motivational shortcomings. Because generalized self-efficacy failed to correlate to increased test performance, future research needs to disentangle the effective components of goal-setting instructions. Task-specific self-efficacy as well as enhancement of task-focused attention might underlie the significant goal-setting effect in depressed patients.
authors.affiliation: Department of Psychiatry, University of Mainz, Mainz, Germany. scheurich@psychiatrie.klinik.uni-mainz.de
authors.forename: A
authors.initials: A
authors.lastname: Scheurich
authors.forename: A
authors.initials: A
authors.lastname: Fellgiebel
authors.forename: I
authors.initials: I
authors.lastname: Schermuly
authors.forename: S
authors.initials: S
authors.lastname: Bauer
authors.forename: R
authors.initials: R
authors.lastname: Wölfges
authors.forename: M J
authors.initials: MJ
authors.lastname: Müller
mesh_terms: D000328:Adult; D003072:Cognition Disorders / Q000175:diagnosis* / Q000453:epidemiology*; D003865:Major Depressive Disorder / Q000175:diagnosis* / Q000453:epidemiology* / Q000523:psychology; D005260:Female; D006040:Goals; D006801:Humans; D008297:Male; D009042:Motivation; D009483:Neuropsychological Tests; D015995:Prevalence; D011596:Psychomotor Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D020377:Self Efficacy; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D014706:Verbal Learning