Parkinson's disease is common. It is estimated to affect around one in 200 people in the developed world (between six and 11 people per general practice in the United Kingdom).1 For many patients, care is shared between general practitioners, geriatricians, general physicians, and neurologists, often alongside specialist nurses. Motor symptoms and signs of Parkinson's disease are well recognised, yet the behavioural problems are less well known, particularly the recently described problems of pathological gambling and other addictive behaviours.2 3 4 5 6 7Pathological gambling is an impulse control disorder characterised by excessive gambling.8 The prevalence of pathological gambling in Parkinson's disease is about 3.4%, rising to 7.2% in patients taking dopamine agonists.6 In contrast, the lifetime prevalence of pathological gambling in the general population in the …