A notable 3.2 million Australians are affected by depression. Simultaneously, only a few Australians adhere to recommended dietary or physical activity guidelines. How do these issues relate? Our groundbreaking study, published this week, demonstrates that enhancing diet and increasing physical activity can be as effective as therapy with a psychologist for addressing low-grade depression. Previous research, including our own, has shown that “lifestyle” therapies are beneficial for depression, but they had not been directly compared to psychological therapies until now. In the face of a nationwide shortage of mental health professionals, our study suggests a potential solution.
As lifestyle counseling was found to be as effective as psychological therapy, our findings indicate that dietitians and exercise physiologists could have a future role in managing depression. During the extensive COVID lockdowns, the distress levels of Victorians were notably high and widespread, while face-to-face mental health services were constrained. Our trial focused on individuals in Victoria experiencing increased distress, signifying at least mild depression but not necessarily a diagnosed mental disorder. Common symptoms included feelings of sadness, hopelessness, irritability, or tearfulness. We collaborated with our local mental health service to recruit 182 adults and provided group-based Zoom sessions.
All participants attended up to six sessions over eight weeks, led by health professionals. Half of the participants were randomly chosen to join a program co-led by a dietitian and an exercise physiologist, called the lifestyle program, which involved setting nutrition and exercise goals. The other group participated in psychotherapy sessions conducted by two psychologists, using cognitive behavioral therapy (CBT), the standard approach for treating depression in group settings and remotely. Participants in both groups could continue with existing treatments, such as antidepressant medication. Both groups received workbooks and hampers; the lifestyle group received a food hamper, while the psychotherapy group received items like a coloring book, stress ball, and head massager. We observed similar outcomes in both programs.
At the trial’s start, each participant’s self-reported mental health was scored, and these scores were reassessed at the program’s conclusion. Over the eight weeks, symptoms of depression decreased by 42% in the lifestyle group and 37% in the psychotherapy group. This difference wasn’t statistically or clinically significant, so we concluded both treatments were equally effective. Some variations were noted between the groups: those in the lifestyle program improved their diets, whereas participants in the psychotherapy group felt they had increased social support, which refers to how connected they felt to others, compared to the beginning of the treatment. Both groups increased their physical activity. This was anticipated for the lifestyle group but less so for the psychotherapy group. It might be because they were aware of participating in a lifestyle-related research study and subconsciously altered their activity levels, or it could be a positive side effect of engaging in psychotherapy.
The cost difference between the programs was minimal, with the lifestyle program being slightly less expensive at A$482 per participant, compared to $503 for psychotherapy, due to differing hourly rates between dietitians, exercise physiologists, and psychologists. The demand for mental health services in Australia is growing, while the supply of professionals faces worsening shortages nationwide. Psychologists, who deliver about half of mental health services, often have lengthy waiting periods. Our results propose that with proper training and guidelines, allied health professionals specializing in diet and exercise could partially bridge this gap.
Lifestyle therapies can be integrated with psychology sessions for multi-disciplinary care, though diet and exercise therapies could be particularly beneficial for those on psychologists’ waitlists, possibly receiving no other professional support in the meantime. Many dietitians and exercise physiologists already possess advanced skills and knowledge in encouraging behavioral change. Most accredited practicing dietitians are experienced in managing eating disorders or gastrointestinal conditions, which often coincide with depression.
There is also a financial consideration, as it is generally cheaper to train a dietitian, costing $153,039, compared to a psychologist at $189,063, and it requires less time. Australians with chronic conditions, such as diabetes, can access subsidized dietitian and exercise physiologist appointments under various Medicare treatment plans. Those with eating disorders are also eligible for subsidized sessions with dietitians. However, mental health care plans for individuals with depression do not currently offer subsidized sessions with dietitians or exercise physiologists, despite advocacy from peak bodies.
Enhanced training, skill development, and Medicare subsidies would be essential to enable dietitians and exercise physiologists to contribute to mental health care. Our training and clinical guidelines are designed to support clinicians offering lifestyle-based mental health care within their scope of practice. Our trial was conducted during COVID lockdowns, involving participants with at least mild symptoms of depression who may not have a diagnosed mental disorder. We are now working to replicate these findings and have initiated a study open to Australians with mental health conditions such as major depression or bipolar disorder.