Abstract

INTRODUCTION

Neuropsychiatric and cognitive symptoms – depression, anxiety, psychosis and dementia – are common in Parkinson’s Disease (PD) (Table 1). Moreover, they are frequently a major source of distress, both to patients and their families, and can be even more debilitating than the motor problems. Indeed, their presence, particularly dementia and psychosis, is an important predictor of nursing home placement.

Neuropsychiatric and cognitive symptoms in PD may occur because of the underlying pathological changes in the brain, drug treatment, or concurrent illnesses. There are significant dopaminergic and other neurotransmitter deficiencies in the frontal and limbic areas in PD, which may cause neuropsychiatric and cognitive problems. Whilst dopaminomimetic agents improve motor symptoms, they may also stimulate dopaminergic receptors in the frontal and limbic areas, resulting in psychotic symptoms. Other drugs such as anticholinergics can cause confusion or amnesia. Co-morbid conditions and diseases may also impair cognitive function and behaviour.

While dementia is difficult