Patients’ characteristics and the presence of psychosis

		Total sample		Psychosis		p Value
		Total sample		Yes	No	p Value
Patients (n)	100	30	70
Age (y):
Mean	71	71.8	71	NS
SD	6.8	4.5	7.5
Age at onset:
Mean	64	61.6	64.7	NS
SD	8.9	8.2	9.1
Duration of illness (y):
Mean	7	10	6.3	<0.02
SD	5.7	7.1	4.6
Dose of levodopa (mg/day):
Mean	455	506	433	NS
SD	353	320	367
Dose of selegeline (mg/day):
Mean	3.8	2.8	4.1	NS
SD	5.7	4.3	6.1
Side of onset total (n=100):
Right	43	16	27	NS
Left	45	9	36
Side of onset cognitively unimpaired (n=62):
Right	25	7	18	<0.03
Left	32	2	30	<0.03
EPS at onset (n=95):
Tremor	55	13	42	NS
Rigidity	19	4	15
Akinesia	21	10	11