Apathy
Apathy means that a person lacks motivation, desire, and interest to do something. Though the cause of apathy is unclear, research indicates that it's due to a chemical imbalance and structural changes in the brain. Often apathy is more frustrating for you than your person with Parkinson's because your person has lost the capacity to care about whatever it is you are hoping they will do.
Some care partners worry about their loved ones sitting on the couch all day and not showing interest in anything. That is considered apathy. You may even find that your loved one loses interest in activities they once adored - that is apathy. For example, let's say your loved one never missed a World Series Game. Even though you remind them that it is on the television, and they might like to see it - they may not express interest. This is an example of apathy.
That attitude might be acceptable for your person with Parkinson's, but it will likely cause severe frustration for you. So, it's critical to work with your person's physician to obtain an accurate diagnosis of apathy. Apathy seems to parallel cognitive decline with disorganization and memory loss, and medications for cognitive problems appear to work best for apathetic people.
In addition to experimenting with medications, you might consider making a plan for your person to get out of the house daily. If you plan the day of activities ahead of time, your person can just step into them. Explore new places. Go for a picnic in a park you've never visited. Try out new restaurants. Connect with people in your community who haven't always been part of your social "circle." Wander around a museum that's new to you and your loved one. New and novel experiences that shake up your routine may help shake off some of the apathy your person is experiencing.
While routines are great for medication timing and meals - organizing time and shaking up the routine in between those times, or learning t0 manage them on the go - can be very helpful in decreasing apathy.
Sources:
The Davis Phinney Foundation. Page 86. My person with Parkinson's has become apathetic about everything. What can/should I do? Every Victory Counts for Care Partners. "Manual." Sixth Edition, 2021.