VIENNA – An adjunctive aerobic exercise program improved cognitive impairment in patients hospitalized for depression in a Swiss randomized controlled trial, Christian Imboden, MD, reported at the annual congress of the European College of Neuropsychopharmacology.
This study addresses a major unmet need in the treatment of depression: namely, options to improve the cognitive dysfunction that accompanies the mood disorder.
Bruce Jancin/Frontline Medical News
Dr. Christian Imboden
He presented a study involving 33 inpatients with a mean baseline score of 21.4 on the 17-item Hamilton Depression Rating Scale. They averaged just under 38 years of age. Fifteen were hospitalized for a first episode of major depressive disorder, 15 had recurrent depression, and 3 had a diagnosis of bipolar depression.
Participants were randomized to the 6-week endurance exercise program or to a standardized stretching and coordination program that met three times per week as a control arm. The exercise group was required to burn 17.5 kcal per kilo of body weight per week on an indoor bicycle at 60%-75% of their maximal age-appropriate heart rate. Cognitive variables were measured at baseline and after 6 weeks using the German-language TAP-test version 2.3.
At the end of 6 weeks, the 16 patients in the exercise group demonstrated significantly greater improvement in working memory reaction time than controls.
“It’s a medium effect size for working memory,” Dr. Imboden said.
The exercisers also showed a trend, albeit not statistically significant, for greater improvement on a measure of alertness, compared with the controls.
The exercise group and controls showed similar improvements in core depressive symptoms over time. After 6 weeks, their mean Hamilton score had improved from 21.7 to 8.6. This result differs from numerous prior studies by other investigators, which have found – typically in outpatients – that exercise significantly reduced depressive symptom severity relative to controls in patients with mild to moderate depression.
Dr. Imboden believes he knows the explanation for the divergent findings. “We have a very effective inpatient treatment program with evidence-based pharmacology, CBT [cognitive-behavioral therapy], and CBT-I for sleep problems. All of our patients were below 10 on the Hamilton score. I think the added value of exercise is very difficult to show under these circumstances, especially with a small sample size,” he said in an interview.
Also, the control arms in exercise research studies often tend to show a large placebo effect. When sedentary patients in the depth of depression are able to overcome their lassitude and sign up for an exercise trial, even simple stretching represents a significant increase in bodily movement, the psychiatrist added.
The biggest need now is to come up with ways to facilitate the transfer of exercise programs from the treatment setting into posttreatment daily life, according to Dr. Imboden.
“Everybody who’s exercising knows it’s helpful, but it can be difficult to create a routine,” he said.
The study was funded by a health research foundation grant, a Swiss health insurance company, and the Canton of Solothurn. Dr. Imboden reported having no financial disclosures.