To explore or establish the relationship between cognitive, mood and motor symptoms in PD to scores on depression rating scales in a naturalistic setting.

Inclusion_Criteria:

Observation criteria:

• are able to provide written informed consent in accordance with Good Clinical Practice (GCP) and local legislation
• have idiopathic Parkinsons disease according to the United Kingdom Parkinsons Disease Society Brain Bank Diagnostic Criteria for Parkinsons disease
• show no impairment of cognitive function (MMSE score ?24)
• are with or without symptoms of depression (full range)
• are stable on anti-Parkinson/anti-depressive treatment for at least 1 month before entering the study
• are or are not on concomitant antidepressant treatment
• are in the on state during the observation period
• did not previously undergo PD surgery