[Psychometric properties of a German version of the Apathy Evaluation Scale].

Apathy is a common feature of a variety of different psychiatric, neurological, and medical disorders. It can be defined as lack of motivation affecting cognitive, emotional, and overt behavioural aspects. Despite being associated with other clinical disorders, apathy can also occur as an independent syndrome (e. g., after brain injuries), now depicting a primary loss of motivation. However, apathy is predominantly assessed within the scope of superordinate psychiatric disorders. As a syndrome-independent scale, the Apathy Evaluation Scale (AES) claims to assess levels of apathy in different disorders. The aim of the present study is to provide German speaking researchers with an authorized German translation of the AES (AES (D)). The scale was evaluated in a sample of 217 subjects, consisting of patients suffering from dementia (n=120), remission-phase schizophrenia (n=20), Parkinson's disease (n=12), stroke (n=28), as well as elderly healthy controls (n=37). Preliminary results concerning the factorial structure, item characteristics, reliability, and construct validity demonstrate favourable statistical properties and suggest that the AESD is comparable to its original. The scale seems well-suited to detect apathy in different clinical groups. Differences between informant sources (clinician interview, self-, and informant ratings) seem to be related to the severity of symptoms or expert practice.