Aerobic Exercise Improves Cognition in Depression

Liam Davenport

June 21, 2017

COPENHAGEN, Denmark ― Adding aerobic exercise to multimodal antidepressant therapy appears to improve cognitive function in clinically depressed inpatients, new research suggests.

Investigators led by Christian Imboden, MD, Psychiatric Services Solothurn, in Switzerland, found that 6 weeks of exercise three times a week significantly improved scores on a measure of working memory for patients enrolled in a control stretching program, although there was no additional impact on symptom severity.

The team said regular aerobic exercise as an add-on to multimodal antidepressant therapy "may contribute to an improved course of cognitive symptoms among clinically depressed patients."

Although exercise did not affect symptom severity, they believe that "this may be due to ceiling effects caused by an already highly effective multimodal treatment regime."

The findings were presented here as a poster at the 13th World Congress of Biological Psychiatry.

Little Data on Cognitive Function

Although there have been studies on the effects of aerobic exercise on symptom severity in patients with mild to moderate depression, there is a general lack of data on the effect of exercise on cognitive function in patients with depression.

To investigate further, the team studied inpatients who had been diagnosed with depression and who had a score greater than 16 on the Hamilton Depression Scale (HDRS-17). The patients were randomly assigned to either endurance exercise or a standardized stretching and coordination program.

The endurance exercise took place on indoor bicycles. The target for energy expenditure was 17.5 kcal/kg/week, with patients exercising at 60% to 75% of their maximum heart rate. The exercise and control interventions took place three times per week for 6 consecutive weeks as an add-on to multimodal antidepressant treatment.

A total of 34 patients were recruited, with 17 in each group. The mean age of the patients was 38.9 years, of whom 50% were women and 41.2% were smokers. The mean body mass index was 24.7 kg/m2.

The mean duration of the current depressive episode was 19.9 weeks, and the mean number of previous depressive episodes was 2.6. The mean age at onset of depression was 32.2 years. There were no significant differences at baseline between the exercise and control groups.

The results showed that there was a significant decrease in mean HDRS-17 score, from 21.5 at baseline to 8.6 at 6 weeks, with no significant difference between the exercise and control groups.

By week 6, there was a significant reduction in the median reaction time for working memory in the exercise group compared with the control group, at 508.8 ms vs 622.0 ms (P = .021).

Dr Imboden told Medscape Medical News that there is "a big problem with cognitive symptoms, and we don't really have antidepressants that help. Patients usually suffer from cognitive symptoms for months after remission, which can impact return to work, among other things.

"So, I think it's important to have opportunities for other means of treatment to help and improve cognitive problems, and I think exercise might fit in there as one possibility," he added.

Dr Imboden noted the beneficial impact of aerobic exercise on cognition in depressive patients is "kind of logical," given its protective effect against dementia and its anti-inflammatory and putative neurogenesis effects.

"I do think that implementing exercise into inpatient and outpatient programs and also getting people to exercise more during everyday life and implementing it into their life might benefit them," he said.

Promising Results

Paolo Brambilla, MD, PhD, Department of Neurosciences and Mental Health, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, University of Milan, Italy, chaired the poster tour.

He told Medscape Medical News that "this is an interesting approach to augment the impact of antidepressants."

Dr Brambilla said that studies of aerobic exercise such as this are "very difficult to carry out" because they need to be performed by a multidisciplinary team and the patients have to be "very compliant" to the exercise regime.

"But, at the end of the day, those are still promising results, but they probably need to be expanded with some neurobiological data, like EEG, MRI, or neurofeedback, for instance, to further explore the possible neurobiological mechanism of action of exercise in improving depression."

The study was financed by grants from the Gottfried and Julia Bangerter-Rhyner Foundation, the Helsana health insurance company, and the canton of Solothurn. No significant financial relationships have been reported.

13th World Congress of Biological Psychiatry 2017 Annual Meeting.


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