Improving Australia’s population mental health: An ounce of prevention is worth a pound of cure

Jorm (2018) reports an absence of reduction in the prevalence of mental disorders or rates of suicide in the Australian population between 2006 and 2015. This is despite massive investment in Australian mental health care, largely through the implementation of the Better Access Scheme. He proposes four explanations for this lack of change: an inadequate dose of treatment, services not delivered to those in need, lack of fidelity to effective treatments and a paucity of initiatives to address the social determinants of mental illness. It is plausible that all of these may explain, to varying degrees, the persisting high rates of mental disorders and suicide. However, we assert that the primary reason is the absence of strategy for the prevention of mental disorders.

The Better Access Scheme can only increase remission and delay relapse

The epidemiology of an illness is determined by four parameters (Figure 1). Prevalence is positively correlated with incidence and relapse of the disorder and negatively correlated with remission and mortality. Pragmatically, policy-makers can only influence the prevalence of mental illness by targeting incidence, remission and relapse. As all people referred for mental health care through the Better Access Scheme had a diagnosable mental disorder, this initiative had to increase remission and decrease relapse in order to reduce mental disorder prevalence.

Figure 1.

Incidence, remission, relapse and mortality influence the prevalence of an illness.

Psychological therapies are effective in reducing symptoms of common mental disorders. However, this is different to achieving complete illness remission. Cuijpers et al. (2014) showed that 62% of adults with major depressive disorder (MDD) who received a psychological therapy achieved remission, compared with 48% of patients who received treatment as usual. Receipt of gold standard psychological interventions only enabled an additional 14% of patients to achieve remission compared to usual care (Cuijpers et al., 2014). While treatment remains important for reducing symptoms of distress among those with mental illness, the increase in remission attributable to psychological therapy is very modest. The natural history of common mental disorders is such that many will recover with minimal intervention.

Relapse prevention is the second method for reducing prevalence. Mental disorders are typically chronic episodic conditions, with relapses frequently precipitated by stressors from work, family, interpersonal events and physical illness. Few studies examining the effectiveness of psychological interventions in preventing relapse have followed participants over an adequate duration of time. Paykel et al. (2005) reported outcomes of participants with depression over 6 years who were randomised to either 18 weeks of cognitive behavioural therapy (CBT) plus medication and clinical management, or medication and clinical management. Those receiving CBT had a greater duration of time to relapse. By 4 years however, the proportion of people in each of the two groups who had relapsed was the same (approximately 60%). Even with high-fidelity treatment for the duration of 18 weeks, relapse from depression is at best delayed.

Setting realistic expectations

The Better Access Scheme has failed to achieve a reduction in the prevalence of mental disorders due to its focus on improving the uptake of treatment rather than the reduction of incidence. Incidence can only be reduced by targeting the social determinants and risk factors for mental disorders. Importantly, many of these are shared with other non-communicable diseases such as cardiovascular disease, malignancy and obesity. Jorm (2018) identified social determinants of poverty, low education, low-quality diet, loneliness and social isolation, and physical illness. In addition, much of the burden of mental illness is attributable to risk factors of adverse childhood experiences, in particular parental mental illness, interpersonal violence, child maltreatment and bullying in adolescence (Kieling et al., 2011). Together, these account for the persistently high burden of mental illness.

Reducing the prevalence of mental disorders

The Better Access Scheme should not be seen as a failed initiative. Jorm (2018) reports that studies showing Australians with high levels of psychological distress are accessing care, which is positive. However, to reduce the prevalence of mental disorders and the suicide rate, comprehensive prevention strategies need to be implemented in tandem with treatment services. This requires a combination of public health initiatives, such as improving parenting skills and treating maternal mental illness (Patel et al., 2015), combined with social policies which improve the determinants of health.

Through the lens of public health and epidemiology, one can clearly see that the Better Access Scheme alone was never going to reduce the prevalence of mental disorders and suicide. These arise from a complex interplay of biopsychosocial factors and reform of health services in isolation is inadequate. Jorm (2018) provides a timely reminder for policy-makers and service reformers to be cognisant of the factors influencing the prevalence of mental illness. To improve the population’s mental health, risk factors and social determinants must be addressed, in addition to effectively treating those who are living with mental illness.