No gain from rise of antidepressants

A MAJOR “quality gap” in the treatment of depression is seeing an increased use of antidepressants and psychological therapies without a commensurate improvement in outcomes, says a leading mental health expert.

Professor Anthony Jorm, head of the Population Mental Health group within the Centre for Mental Health at the Melbourne School of Population and Global Health, said Australia has seen a large increase in the treatment of depression but the outcomes have been underwhelming.

“We have had no population health gain in depression prevalence despite increases in both antidepressant treatment and psychological therapy. In theory, greater uptake should produce a population health gain … but because of a major ‘quality gap’ we have not seen the expected benefits,” Professor Jorm told MJA InSight.

Professor Jorm’s comments came as experts wrote in the MJA that the effectiveness of antidepressant medication had fallen short of initial expectations, despite around 1 in 10 Australians now taking an antidepressant. The authors noted that Australia had one of the highest rates of antidepressant prescribing in the world, with rates doubling since 2000. 

“An unfortunate nexus has developed between the diagnosis of depression of any severity and the reflexive prescription of medications as monotherapy, for which the medical profession must accept some responsibility,” wrote Professors Christopher Davey and Andrew Chanen of Orygen, the National Centre of Excellence in Youth Mental Health.

They wrote that antidepressant medications had an important role in the treatment of mild-to-moderate depression, but they should be prescribed as part of an overall treatment plan.

“All patients should be offered psychotherapy where it is available, and medication should be considered if: the depression is of at least moderate severity; psychotherapy is refused; or psychotherapy has not been effective,” they wrote, adding that healthy eating and exercise should also be recommended.

Professor Jorm said that a greater use of combined treatment would make little difference without improvements in the targeting of pharmacotherapy and quality of psychological interventions.

“Much of the antidepressant use in Australia is for chronic mild depression, but randomised controlled trials do not support their effectiveness for this group,” he said.

“When we look at the distribution of use, we find that antidepressant use rises steadily with age, with older people being the heaviest users. However, epidemiological studies show that older people are at lower risk for depression than younger adults.

“Similarly, with psychological therapy, many people receive too few sessions to be effective and it is not clear that therapists implement the therapy to the standard of treatment manuals used in trials.”

Professor Harvey Whiteford, professor of Population Mental Health at the University of Queensland, agreed that there was work to be done in better targeting therapies.

“We still don’t have good alignment between the needs of the patient and the intervention which can effectively respond to that. We have an over-reliance on medication and an under-reliance on psychological therapies.”

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Professor Whitehead said the Better Access to Mental Health Care initiative was introduced in 2006 to improve access to psychological treatments and reduce unnecessary reliance on pharmacotherapy. He said that the initiative had successfully increased psychological treatment – with research conducted by Professor Whiteford and colleagues finding that treatment rates had grown from 37% in 2006-07 to 46% in 2009-10 – but the use of pharmacotherapy has also continued to rise.

“What appears to happen when you get to a GP is the GP would prescribe medication and refer to the Better Access program for psychological counselling,” he said.

Professor Whiteford hoped that, over time, a stepped approach to treatment for mild-to-moderate mental disorders would become more common, with self-help the first port of call, followed by referral for psychological treatment and then medication. 

He agreed that greater emphasis was needed on the quality of psychological services.

“[We need to know] what happens once the person gets inside the psychologist’s consulting rooms – are they getting evidence-based psychological therapies? Or are they getting a non-evidence based counselling, which isn’t really going to treat their mental health problem,” he said.
Prevention also needed to be a focus, said Professor Jorm.

“We are putting all of our resources into treatment and very little into prevention,” he said. “It’s a big contrast to what you see with major physical diseases, like cancer and cardiovascular disease, where we do have a strong preventive arm as well as a treatment arm.”

Dr Natalie Parletta, Senior Research Fellow at the Centre for Population Health Research at the University of South Australia, said that the role of diet and exercise in mental health care prevention and treatment was often overlooked. 

“There is good evidence now for whole diets being protective against developing depression, and conversely that unhealthy diets increase the risk of developing depression over time,” Dr Parletta told MJA InSight.

Dr Parletta said she was leading one of two randomised controlled trials currently underway in Australia to further investigate the role of diet in mental health.

“There is a strong underlying rationale for the role of diet and nutrients, not only for improving our inflammatory status, which is linked to depression, but also there are a range of nutrients that are important for healthy brain function,” she said, citing the crucial role of nutrients, such as vitamin E, various B vitamins, magnesium and zinc, in neurotransmission. 

“Omega-3s, which are critical nutrients for brain function, have also received a lot of research interest in recent years with regard to mental health, including evidence for a role in reducing depressive symptoms,” she said.

“Additionally, there is a growing body of evidence around the role of the gut microbiome in the gut-brain axis which is opening up a whole new area of exploration with regard to mental health,” she said.