Role of demotivation and affective disorders in apathy in patients with Parkinson's disease without dementia and depression

Abstract

to assess the role of demotivation and various affective factors in apathy in patients with Parkinson's disease (PD) without dementia and depression. 20 patients and 20 control subjects matched with age, education level, and genre. apathy was assessed by the Apathy evaluation scale (AES) and by a specific scale including a quantitative evaluation of 32 intentional activities and a qualitative assessment of the causes of attribution of restricted activities by a semi-structured interview (GDAS). Four causal attributions were distinguished: E = related to external factors, M = disease symptoms related, C = affective disturbances with preservation of motivation, and D = demotivation. The results were compared to a battery of tests including cognitive evaluation (mini-mental state and Mattis dementia rating scale for global evaluation, selecting reminding test for memory; Stroop test for inhibition, and six element test for planification); affective evaluation (Montgomery & Asberg and Hamilton depression rating scales for depression, emotional disturbances by the Abrams and Taylor scale, the Depression mood scale, and the International picture system), premorbid personality (NEOPI-R), and defensive psychological mechanisms (DSQ-40); functional assessment by a combined scale including the Self-maintenance physical scale and the Instrumental activities of daily living (Lawton) and the Social activities scale (Katz & Lyerly), the Disability assessment scale, and the UPDRS. apathy was found in 25% of the patients according to the AES, but only in 15% according to the GDAS. Scores on cognitive and affective evaluation were higher in patients than in controls but only emotional blunting was correlated to apathy. Some results coud be interpreted in favor of a premorbid personality disorder in patients with PD, but were not correlated to apathy. Causal attribution was M in 38% of cases of reduced activities, D in 30%, E in 22%, and C in 10%. emotional blunting was the main correlate of apathy in PD patients without dementia and depression. Demotivation was the causal mechanism in only 30% of the patients with apathy.