Adrienne O’Neill and Sophie Mahoney, The Conversation
MELBOURNE: Around 3.2 million Australians live with depression. Yet fewer are meeting recommended diet and exercise guidelines. What does the two have to do with each other? A world-first clinical trial published this week showed that improving diet and increasing exercise was as effective as psychologist-led therapy in treating mild depression.
Previous studies (including our own) have found that “lifestyle” therapies can be effective for depression, but until now lifestyle therapies have not been directly compared with psychological therapies.
With a national shortage of mental health professionals, our study points to a potential solution: Because lifestyle counseling was found to be as effective as psychotherapy, our findings suggest that nutritionists and exercise physiologists may have a role to play in managing depression in the future.
What did we measure in our study?
As the COVID-19 lockdown dragged on, stress levels among Victorians were high and widespread, and face-to-face mental health services were limited.
Our study looked at people in Victoria who were highly stressed and had at least mild depression but not necessarily a diagnosed mental disorder. Typical symptoms included feeling down, hopeless, irritability and tearfulness.
We partnered with local mental health services to recruit 182 adults and deliver group-based sessions over Zoom. All participants attended up to six sessions over eight weeks, supervised by a health professional.
Half were randomly assigned to take part in a program run jointly by a certified dietitian and an exercise physiologist. Called the Lifestyle Program, the group was given nutrition and exercise goals that included: – Eat a variety of foods – Choose plant-based foods that are high in fiber – Include high-quality fats – Limit discretionary foods, such as foods high in saturated fats and added sugars – Engage in enjoyable exercise.
The second group participated in psychotherapy sessions hosted by two psychologists. The psychotherapy program used cognitive behavioral therapy (CBT), the gold standard for depression treatment delivered in groups and at a distance.
In both groups, participants were able to continue their existing treatment (e.g., taking antidepressants). We gave both groups a workbook and gift items: the lifestyle group received a food gift box, and the psychotherapy group received items like coloring books, stress balls, and head massagers.
Lifestyle Therapies Are Just as Effective
Each program produced similar results. At the start of the studies, each participant was given a score based on their self-reported mental health, and then they were measured again at the end of the programs.
Over the course of eight weeks, these scores showed that participants in the lifestyle program (42%) and the psychotherapy program (37%) had reduced symptoms of depression. Because this difference was neither statistically nor clinically significant, it can be concluded that both treatments were equally effective.
There were some slight differences between the groups: those who took part in the lifestyle program improved their eating habits, while those who took part in the psychological therapy program reported an increase in social support – how connected they felt to other people – compared to when treatment began.
Participants in both programs increased their physical activity. This was expected for participants in the lifestyle program but unexpected for those in the psychotherapy program. This may be because participants knew they were taking part in a lifestyle study and subconsciously changed their activity patterns, or it may be a positive by-product of receiving psychotherapy.
There was also no significant difference in cost: the cost of delivering the lifestyle program was AUD$482 per participant, while psychological therapy was slightly less at AUD$503, due to different hourly rates for nutritionists, exercise physiologists and psychologists.
What does this mean for the mental health workforce shortage?
Demand for mental health services is rising in Australia, while there is a serious workforce shortage across the country.
Psychologists, who provide around half of mental health services, can have long wait times. Our findings suggest that with the right training and guidelines, health professionals specialising in diet and exercise could help fill this gap.
Lifestyle therapy can be combined with psychology sessions for multidisciplinary care, but diet and exercise therapy can be particularly effective for people who may not have access to other specialist support while waiting to see a psychologist.
Many dietitians and exercise physiologists already have advanced skills and expertise in promoting behavior change, and most licensed dietitians in practice are trained in managing eating disorders and gastrointestinal disorders, which often overlap with depression.
There is also the cost argument: training a nutritionist is overall cheaper ($153,039) and less time-consuming ($189,063) than training a psychologist.
Potential barriers
Australians with chronic conditions (such as diabetes) can access subsidised dietitian and exercise physiologist treatment under various Medicare treatment plans. People with eating disorders can also access subsidised dietitian treatment. However, mental health care plans for people with depression do not support subsidised sessions with a dietitian or exercise physiologist, despite peak body recommendations.
Training, upskilling and increased Medicare subsidies will be needed to support nutritionists and exercise physiologists in treating mental health issues.
Our training and clinical guidelines are intended to help clinicians implement lifestyle-based mental health care within their scope of practice (activities that health care providers can perform).
Our goal
“Our trials took place during the COVID-19 lockdown and looked at people who were not necessarily mentally ill but had at least mild symptoms of depression. We aim to replicate these findings and are currently conducting studies in Australians with mental illnesses such as severe depression and bipolar disorder.”
(Adrian O’Neill is Professor in the Centre for Food and Mood, Deakin University; Sophie Mahoney is Associate Research Fellow in the Centre for Food and Mood, Deakin University)
Published August 4, 2024 06:49 IST
