Depression in Parkinson's disease under diagnosed

Jul 10 2007

While depression appears to be common in early Parkinson's disease (PD), it is often not treated or diagnosed, according to newly released research.

A contingent of researchers from across North America found that just over 27 per cent of PD subjects screened positive for depression, while 40 per cent of subjects' depression went untreated.

This study, published in Neurology journal, authored by Bernard Ravina, MD at the University of Rochester and funded by the National Institutes of Health in the USA, is the first to systematically examine the impact of depressive symptoms in early, untreated PD. Previous research has found that depression, in some form, affects up to 50 per cent of patients with PD and is associated with increased disability and reduced quality of life.

“Our results show that depression in PD appears to be under diagnosed, especially at the early stages of PD. That may be because symptoms of depression, such as fatigue and insomnia, may be attributed to PD rather than as symptoms of depression,” said Dr. Richard Camicioli, assistant neurology professor at the University of Alberta and a co-author of the study. “As seen in this study, many treated patients remained depressed and may require more intensive psychiatric treatment.”

Depression was also found to be associated with impairment on daily life activities, such as eating, bathing and dressing.

“Over time it appears that depression does not actually influence the progression of motor signs, but increases the disability associated with a given level of observational motor signs of PD,” said Camicioli.

For this study, 413 early, untreated PD subjects were administered the 15-item Geriatric Depression Scale (GDS-15), a validated screening tool to assess for depressive symptoms and the use of antidepressant or referral for further psychiatric health evaluation as a marker for the treatment of depression.

In another study based on data collected at the University of Alberta and funded by the Canadian Institutes of Health Research, Dr. Richard Camicioli has also found that depressive symptoms were the largest influence on health-related quality of life in older people with Parkinson's disease.

“While we found that depression is common in early Parkinson's disease diagnosis, we've also uncovered that depressive symptoms have the most significant influence on health-related quality of life in older people with Parkinson's disease,” said Camicioli. “That is why it is crucial for health care professionals to make an effort to detect, diagnose, and properly treat depression in Parkinson patients.”