Table 4.

The Comparison of the Average Onset Ages Between Patients With and Without PD With and Without a Prior Diagnosis of ADHD.

	Patients with a prior diagnosis of ADHD	Patients without a prior diagnosis of ADHD	P value for t-test
Patients with PD	56.9 ± 21.3	72.5 ± 11.0	<0.001
Patients without PD	69.5 ± 9.8	70.3 ± 14.2	0.403

ADHD: attention-deficit hyperactivity disorder; PD: Parkinson’s disease.