New Delhi: Science has confirmed what common wisdom says — exercise is a potent tool to fight depression.
A meta-analysis of 218 randomised controlled trials from across the world to examine the impact of exercise on depression has shown that it is an effective treatment for the condition, with walking or jogging, yoga, and strength training more effective than other exercises, particularly when intense.
The analysis, carried out by researchers in Australia, Denmark, Spain and Finland, has suggested that the specific exercises could be considered alongside psychotherapy and antidepressants as core treatments for depression.
Exercise appeared equally effective for people with and without comorbidities and with different baseline levels of depression, the researchers noted in the study that was published in the British Medical Journal last week.
Dr Rishi Gautam, assistant professor of psychiatry, the George Washington University School of Medicine and Health Sciences, who is not associated with the study directly, underlined that the study highlights the under-appreciated effects of aerobic exercise on depression and mood in general.
Research demonstrates that exercise improves depression by increasing the release of endorphins, which are the happy hormones for the brain and also beneficial in alleviating anxiety, improving sleep and appetite, improving self-confidence and overall coping mechanisms, he said.
Depression, a common mental disorder, involves a depressed mood or loss of pleasure or interest in activities for long periods of time and is different from regular mood changes and feelings about everyday life.
According to the World Health Organization (WHO), an estimated 3.8 percent of the population experiences depression, including 5 percent of adults and 5.7 percent of those aged 60 and above.
A WHO report titled ‘Depression and Other Common Mental Disorders – Global Health Estimates’ released in 2017, had estimated the prevalence of depressive disorders in India at 4.5 percent of the total population.
The latest analysis says that many exercise modalities have previously been found to be effective treatments for depression, particularly walking or jogging, strength training, and yoga, but confidence in many of the findings was low.
“We found preliminary data that may help practitioners tailor interventions to individuals, for example, yoga for older men, strength training for younger women,” the authors have said.
Depression is a leading cause of disability, and exercise is often recommended alongside first-line treatments such as pharmacotherapy and psychotherapy, but treatment guidelines and previous reviews disagree on how to prescribe exercise to best treat depression, the latest study has said.
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What the researchers found
The analysis included 218 unique studies with a total of 495 groups and 14,170 participants.
Compared with active controls, such as usual care and placebo tablets, moderate reductions in depression were found following walking or jogging (in 1,210 people), yoga (in 1,047 people), strength training (in 643 people), mixed aerobic exercises (in 1,286 people), and tai chi or qigong (in 343 people). In contrast, the benefit due to antidepressants was found in 432 people.
The authors summarised that for treating depression, various exercise modalities are well tolerated and effective, particularly walking or jogging, yoga and strength training.
“Effects were comparable to psychotherapy and pharmacotherapy — exercise worked better when more intense,” they said.
According to the findings, compared to active controls, dance was found to lead to significant reduction in depression, followed by moderate reductions for walking or jogging, yoga, strength training, mixed aerobic exercises and tai chi or qigong.
Also, moderate effects were seen on combining exercise with SSRI (selective serotonin reuptake inhibitor) — a widely used type of antidepressant — or combining aerobic exercise with psychotherapy.
Based on the results, the authors stressed that health systems may want to provide these treatments as alternatives or adjuvants to other established interventions like cognitive behavioral therapy and SSRIs, while also attenuating risks to physical health associated with depression.
Dr Nand Kumar, professor of psychiatry at the All India Institute of Medical Sciences (AIIMS) in New Delhi, said that the latest study established that exercise is an effective adjunct treatment or preventative intervention for depression but has a more significant role in the recovery process once the patient regains adequate physical and mental energy with treatment by medicine or psychotherapy.
“Exercise works best whenever there is increased cardiac output, and the new analysis says in general that group exercise was not more effective than individual exercise, except for yoga. But in a non-research setting, group exercise (such as a walk in the park) has the additional benefit of social brain stimulation, hence it is likely to be more effective,” Kumar said.
He also emphasised that the latest findings were significant as a number of trials to examine the effect of exercise on depression had been inconclusive.
Gautam underlined that exercise is beneficial in alleviating anxiety, improving sleep and appetite, improving self-confidence and overall coping mechanisms.
“In fact, exercise is the most natural antidepressant known to us,” he said. “Some people with a more severe form of depression require intensive medication and therapy-based treatment, the effects of which improve multi-fold when exercise is added to the mix.”
Doctors strongly recommend doing some form of aerobic exercise for a minimum of 30 minutes at least three times a week to start seeing some good outcomes. Nonetheless, any amount of exercise is good — there is absolutely no harm, Gautam said.
Policy implications
According to the latest analysis, clinical practice guidelines in the US, the UK, and Australia recommend physical activity as part of treatment for depression but these guidelines do not provide clear and consistent recommendations about dose or exercise modality.
The researchers supported the inclusion of exercise as part of clinical practice guidelines for depression, particularly vigorous intensity exercise.
Doing so may help bridge the gap in treatment coverage by increasing the range of first-line options for patients and health systems, they have said, adding that globally there has been an attempt to reduce stigma associated with seeking treatment for depression, and exercise may support this effort by providing patients with treatment options that carry less stigma.
In low-resource or funding constrained settings, group exercise interventions may provide relatively low-cost alternatives for patients with depression and for health systems, the analysis noted.
“When possible, ideal treatment may involve individualised care with a multidisciplinary team, where exercise professionals could take responsibility for ensuring that the prescription is safe, personalised, challenging, and supported,” the authors have said.
In addition, those delivering psychotherapy may want to direct some time towards tackling cognitive and behavioural barriers to exercise, according to the researchers, who added that exercise professionals might need to be trained in the management of depression and to be mindful of the scope of their practice while providing support to deal with this major cause of disability.
Kumar, meanwhile, said that while the authors observed the effect of exercise to be superior to antidepressants, in major depressive disorder the level of energy and fatigue is so low that the person has inadequate energy to go for exercise.
“However,” he said, “once the depression is lifted, exercise is effective in preventing the recurrence of depression,” he noted.
(Edited by Nida Fatima Siddiqui)
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