Table 1.

Demographic and clinical variables; mean (SD)

	Parkinson’s disease groups
	Normals	Dopa-naive	Dopa-treated with no dyskinesias	Dopa-treated with DID
n	11	17	10	6
Age	53.6 (14.4)	60.9 (14.2)	69.9 (3.2)*	60.3 (8.0)
Hamilton depression scale	1.5 (1.6)	2.6 (2.5)	1.1 (2.8)	2.5 (3.1)
Mini-mental status score	29.6 (0.7)	28.8 (1.9)	28.7 (1.3)	28.7 (2.3)
Hoehn and Yahr stage		1.7 (0.3)	2.6 (0.6)†	2.4 (0.8)†
Symptom duration, years		2.8 (2.9)	7.6 (6.4)	10.8 (6.5)†
Modified UPDRS change		−2.7 (2.2)	−3.6 (3.3)	−3.0 (3.4)
Treatment duration, years			5.9 (5.7)	7.8 (6.8)

^*Significantly different from normals (P < 0.05). 

^†Significantly different from dopa-naive group (P < 0.05).