Hi Val My husband has had PD for 11 years. You did the right thing to get some help for your dad. I'm curius why the ND is not seeing him again for 6 mos. We go every 3-4 months but our meds have not changed for some time now. With the change in your dad's medicine, and a new patient, I would call for an appointment sooner if your dad doesn't do better. Don't hesitate to call the doctor if you have questions, don't carry the burden alone. And don't feel quilty for not understanding the disease sooner-PD advances slowly sometime and we don't notice the day-to-day changes until it is ovious the PD needs additional help.