Motor symptoms, such as tremors, unsteadiness and occasional freezing in place, may come to mind when you think about Parkinson’s disease. But ask psychiatrists what they think about when they consider Parkinson’s, and you’ll hear about depression and anxiety.

Although more than 3 million adults in the U.S. have anxiety or depression, most of them won’t end up with Parkinson’s disease. That said, it may surprise you to learn that 40 percent of patients with Parkinson’s suffer anxiety disorders, either long before their diagnosis or after they have Parkinson’s. Could an anxiety disorder be as much of a marker for Parkinson’s as trembling hands and an unsteady gait?

Anxiety as an Early Warning Sign

It may be that anxiety disorders that are diagnosed as much as two decades before Parkinson’s disease may be a harbinger of the disease, says Gregory Pontone, M.D., director of the Johns Hopkins Movement Disorders Psychiatry Clinic. Parkinson’s disease, like Alzheimer’s disease, has what experts call a long approach, he says, and anxiety may be part of that long approach.

One theory is that the anxiety that comes before Parkinson’s results from the same underlying changes in brain chemistry and circuitry. Others believe that Parkinson’s disease and anxiety share a common genetic risk factor. Either way, taking a closer look at the link can help doctors understand the causes of Parkinson’s and treat patients with the disease.

Types of Anxiety Disorder Linked to Parkinson’s

Research shows that up to 40 percent of Parkinson’s patients have anxiety. This is greater than the rate in people of the same age who don’t have Parkinson’s. That anxiety can take several forms:

• Panic attacks: These are episodes of physical and emotional distress — you may feel as though you can’t breathe or are having a heart attack. A panic attack can last from a few minutes to an hour or more.

• Generalized anxiety disorder: This form is characterized by an overall feeling of nervousness, anxiety, worry and fear that is out of proportion to what’s actually going on in a given moment. You may feel physical symptoms, such as nausea, trouble breathing, sweating, tremors and a feeling that your heart is racing.   

• Social anxiety disorder: Also called social avoidance, this type involves a sense of fear or embarrassment — in this case, because of Parkinson’s symptoms — that keeps you from engaging in normal social situations.

• Fluctuation-associated anxiety: This form of anxiety is specific to the treatment for Parkinson’s disease, says Pontone. Levodopa — a drug that boosts dopamine (a brain chemical that helps regulate movement) and eases Parkinson’s symptoms — can cause dips and spikes in anxiety as your body metabolizes the drug. This rise and fall can bring on feelings of worry and psychological discomfort as well as physical symptoms, such as restlessness and agitation. 

• Anticipatory anxiety: This is out-of-the-ordinary worry about an upcoming event — for example, a trip or a meeting. Your worries are out of proportion to the actual event, and you fear that the worst is going to happen.

Anxiety and Parkinson’s Research

What does this finding mean for the future of diagnosis or treatment of Parkinson’s? Ongoing research is compelling, says Pontone. “Part of what we are doing is looking at anxiety disorders that occur long before the onset of Parkinson’s to see if there are characteristics that may differentiate that anxiety or predict an increased risk of Parkinson’s disease.”

Meanwhile, because there’s an established link between anxiety and Parkinson’s disease, patients and their families should be upfront with their doctors about anxiety symptoms. Behavioral therapy and medications — for example, anti-anxiety meds or antidepressants — can effectively treat anxiety disorders. There’s no need for anyone to suffer in silence.