More Australians are diagnosed with depression and anxiety but it doesn't mean mental illness is rising

Diagnoses of depression and anxiety disorders have risen dramatically over the past eight years. That’s according to new data out today from the Housing Income and Labour Dynamics (HILDA) Survey, which tracks the lives of 17,500 Australians.

The increase spans across all age groups, but is most notably in young people.

The percentage of young women (aged 15-34) who had been diagnosed with these conditions increased from 12.8% in 2009, to 20.1% in 2017.

In young men, there was a similar increase, from 6.1% to 11.2%.

But this doesn’t mean Australians’ mental health is worsening.

Read more: Explainer: what is an anxiety disorder?

What’s behind the numbers?

HILDA surveys collate data on the “reported diagnosis” of depression and anxiety disorders. Many people with these conditions have remained undiagnosed by a health practitioner, so it could simply be a matter of more people seeking professional help and getting diagnosed.

To find out whether there is a real increase, we need to survey a sample of the public about their symptoms rather than ask about whether they have been diagnosed. This has been done for almost two decades in the National Health Survey.

This graph shows the percentage of the population reporting very high levels of depression and anxiety symptoms over the previous month, from 2001 to 2017-18.

Rather than worsening, the nation’s mental health has been steady over this period.

Shouldn’t our mental health be improving?

So it seems while our mental health is not getting worse, we are more likely to get diagnosed. With increased diagnosis, it’s no surprise Australians have been rapidly embracing treatments for mental-health problems.

Antidepressant use has been rising for decades, with Australians now among the world’s highest users. One in ten Australian adults take an antidepressant each day.

Read more: If you're coming off antidepressants, withdrawals and setbacks may be part of the process

Psychological treatment has also skyrocketed, particularly after the Australian government introduced Medicare coverage for psychology services in 2006. There are now around 20 psychology services per year for every 100 Australians.

The real concern is why we’re not seeing any benefit from these large increases in diagnosis and treatment. In theory, our mental health should be improving.

There are two likely reasons for the lack of progress: the treatments are often not up to standard and we have neglected prevention.

Treatment is often poor quality

A number of treatments work for depression and anxiety disorders. However, what Australians receive in practice falls far short of the ideal.

Antidepressants, for example, are most appropriate for severe depression, but are often used to treat people with mild symptoms that reflect difficult life circumstances.

Psychological treatments can be effective, but require many sessions. Around 16 to 20 sessions are recommended to treat depression. Getting a couple of sessions with a psychologist is too often the norm and unlikely to produce much improvement.

Treatments are also not distributed to the people most in need. The biggest users of antidepressants are older people, whereas younger people are more likely to experience severe depression.

Similarly, people in wealthier areas are more likely to get psychological therapy, but depression and anxiety disorders are more common in poorer areas.

Read more: When it's easier to get meds than therapy: how poverty makes it hard to escape mental illness

Prevention is neglected

The big area of neglect in mental health is prevention. Australia achieved enormous gains in physical health during the 20th century, with big drops in premature death. Prevention of disease and injury played a major role in these gains.

We might expect a similar approach to work for mental-health problems, which are the next frontier for improving the nation’s health. However, while we have been putting increasing resources into treatment, prevention has been neglected.

There is now good evidence that prevention of mental-health problems is possible and that it makes good economic sense. For every dollar invested on school-based interventions to reduce bullying, for instance, there is an estimated economic return of $14.

Much could to be done to reduce the major risk factors for mental-health problems which occur during childhood and increase risk right across the lifespan.

Parents who are in conflict with each other and fight a lot, for example, may increase their children’s risk for depression and anxiety disorders, while parents who show warmth and affection towards their children decrease their risk. Parents can be trained to reduce these risk factors and increase protective factors.

Yet successive Australian governments have lacked the political will to invest in prevention.

Where to next?

There is an important opportunity to consider whether Australia should be heading in a very different direction in its approach to mental health. The Australian government has asked the Productivity Commission to investigate mental health.

While we’ve had many previous inquiries, this one is different because it’s looking at the social and economic benefits of mental health to the nation. This broader perspective is important because action on prevention is a whole-of-government concern with resource implications and benefits that extend well beyond the health sector.

Read more: Does more mental health treatment and less stigma produce better mental health?