Robin Williams, Depression, and Parkinson's Disease

Robin Williams never hid his struggles with anxiety and depression. The Parkinson's diagnosis was different. The public only learned of it after the actor took his own life, and the news landed as a second shock on top of the first. What struck many people as a strange coincidence, two heavy illnesses in one person, turns out not to be coincidence at all. The two conditions keep company more often than most of us realize.

Parkinson's has no cure at present, and its symptoms are severe. A person living with it may develop tremors in the jaw, arms, legs, or face. Limbs and torso can stiffen. Movement slows. Coordination and balance erode. These are physical signs of a disease that works on the nervous system, and they tend to worsen over time.

Roughly half of all people with Parkinson's will deal with depression of some kind. The relationship appears to run in both directions. Researchers at Taipei Veterans General Hospital in Taiwan reported that people who are depressed are about three times more likely to later be diagnosed with Parkinson's. And patients who already have Parkinson's, with no prior history of depression, can start showing depressive symptoms as the illness progresses.

Depression often travels with another condition, but the tie to Parkinson's seems to run through shared biology. Studies point to overlapping chemical and hormonal factors, the kind of changes that can help trigger either disease. In Parkinson's, serotonin and dopamine levels can run low, and that shortfall opens the door to depression. One set of brain scans of Parkinson's patients turned up an unusually high number of reuptake pumps for serotonin, the chemical messenger. Serotonin and dopamine both help regulate mood; dopamine also governs movement and aspects of thinking.

A common Parkinson's treatment is dopamine replacement therapy, meant to ease the motor problems the disease causes. Work from the University of Kentucky College of Medicine and the Sanders-Brown Center on Aging complicates that picture, though. Patients who were depressed and took the dopaminergic medication showed worse cognitive performance on the drug than off it. Patients who were not depressed showed the opposite: their thinking sharpened on the medication. The practical lesson is that depressed and non-depressed Parkinson's patients cannot be treated with the same playbook.

Much of that depression goes unaddressed. Northwestern Medicine researchers went through data on 7,000 patients gathered by the National Parkinson's Foundation. Close to a quarter of patients reported depressive symptoms. Among those with the most severe symptoms, only about a third had been prescribed an antidepressant, and fewer still got help from a mental health professional. For patients with milder symptoms, only 10 percent received medication or a referral. Doctors treating Parkinson's were more inclined to act on severe depression, and even then the care often fell short.

"The majority of these patients remained untreated," said Danny Bega, MD, an instructor in the Ken and Ruth Davee Department of Neurology. There's a troubling wrinkle in the numbers. The NPF had classified the treatment sites in the study as Centers of Excellence. If the gap looks like that at the best facilities, the picture for the wider population may be worse. Bega urges physicians to screen Parkinson's patients for depression and to tailor treatment to the individual rather than reach for a default.

Given the risk that dopamine replacement poses to depressed patients, other options matter. Exercise is one of the more encouraging. A study from The Ohio State University Wexner Medical Center found that sustained physical activity improved not only movement but mood. Patients were placed in either a 48-week program (early start) or a 24-week one (delayed start). The early start group saw their depressive symptoms ease more than the delayed start group did. Fitness appeared to help motor function too.

Neurologists who specialize in movement disorders tell their patients the same thing: keep moving, and do it often. Dancing, yoga, tai chi, walking, swimming, almost any low-impact activity can help with coordination. Movement feeds both the muscular and the nervous systems. There's no single prescribed routine. Staying active is simply one of the few things that seems to lift the spirits of people carrying both Parkinson's and depression at once.