Treating Depression and Physical Illness
People with physical illness are at an increased risk of depression, which is linked with a worse prognosis and reduced adherence to treatment. Unfortunately, data on the use of antidepressants in physically ill patients is lacking. Extra care must be taken in prescribing antidepressants to this group because of side effects, possible impact on the liver and kidneys, and the risk of drug interactions.
A recent review looked at the efficacy of antidepressants in physically ill people. It examined 51 studies comparing antidepressants against placebo after six to eight weeks of treatment.
Pooled results showed that antidepressants were significantly better than placebo for tackling depression. However, dropout rates were higher than on placebo, due to side effects including dry mouth and sexual dysfunction. The authors, from King’s College London, London, UK, say that the evidence supports antidepressants, but that further research is required in this population.
Depression is common in Parkinson’s disease, a degenerative disorder of the central nervous system. Rates are estimated at eight to 20 percent of patients. When depression occurs alongside Parkinson’s disease, patients are at risk of more rapid cognitive decline and reduced quality of life. “Recognizing and treating depression in the context of Parkinson’s disease is important in order to reduce disability and improve prognosis,” say Dr. Petros Skapinakis and colleagues at Bristol University, UK.
They report that, in a recent U.S. survey, 63 percent of the prescriptions for depression in Parkinson’s disease patients were for selective serotonin reuptake inhibitors (SSRIs) and 7.5 percent for tricyclic antidepressants (TCAs). They add that treatment of depression in Parkinson’s disease and other medical illnesses poses particular problems.
For example, most antidepressant trials exclude patients with medical illnesses, so results cannot be generalized to these patients. Diagnosis and measures of depression severity in patients with physical diseases may be more difficult because of overlapping symptoms, such as physical changes, fatigue, insomnia, sleep disorders, weight loss, and cognitive dysfunction. In addition, trials of antidepressants in medical illness are usually carried out by independent researchers and are often small.
The Bristol team reviewed ten trials of antidepressants for depression in Parkinson’s disease. Analysis suggested that neither SSRIs nor TCAs were significantly better than placebo. But they write that, due to the limited number of studies and small group sizes, a possible effect cannot be discounted.
“Our results show that the current clinical practice is not supported by strong evidence,” they state, but there is the possibility that patients with Parkinson’s disease may need to take higher doses of antidepressants.