Mental & addictive disorders - Even more important during & after the COVID-19 pandemic.

The upcoming World Mental Health Day1 is a good opportunity to take stock on where we stand with regard to mental and addictive disorders in 2021. The latest global epidemiological assessment of mental and addictive disorders was published for 2019. In that year, the Global Burden of Disease estimated that these disorders comprised about 6.3 per cent of all disability-adjusted life years globally (6.6% for women and 6.0% for men) and 0.5 per cent of all deaths (0.2% for women and 0.8% for men)2. These numbers represent more than 160 million life-years lost due to premature death and disability in 2019, and almost 300,000 deaths. Mental and addictive disorders have had a similar impact for decades, with similar characteristics: these are far more disabling than being lethal. Disability affects women proportionally more than men for mental disorders, men are affected more than women by substance use disorders and both mental and addictive disorders are more prevalent in high-income regions3. The impact on mortality is an underestimate, as people affected by mental and addictive disorders, on an average, die prematurely, although with other causes of death listed on their death certificates4.

The mental and addictive disorders were important before the SARS-CoV-2 or COVID-19 pandemic. The pandemic, however, may have significantly increased the importance of these disorders. Causally, the pandemic may have increased incidence of both mental and affective disorders, and these disorders may have fed into the pandemic. Here we deal with both the causal directions separately.

First, the overwhelming majority of the general population surveys and reviews indicate an increase in stress, and symptoms of anxiety, depression and substance use disorders during the pandemic56. The burden of manifest disorders was more difficult to judge, especially since the healthcare facilities and service utilization were impacted by the pandemic. Potential patients feared accessing services, and healthcare facilities were often closed at least partially, or personnel were shifted around to deal with the COVID-19 pandemic. Thus, while most of the models expect an increase in the burden of mental and addictive disorders in the future, following the COVID-19 pandemic78. The exact extent of this increased burden and its consequences on health care are not clear. In addition to symptoms of the more common mental and substance use disorders, such as depression and other mood disorders, anxiety and alcohol use disorders, evidence suggested that post-traumatic stress symptoms were common among people exposed to the trauma resulting from infectious disease outbreak9. Moreover, the increase of stress and mental and substance use disorder symptoms will likely not only affect the general population but also healthcare workers6710.

It should be noted that the increase in substance use disorders or in substance poisonings does not necessarily mean that the use has increased as well. There are good indications that globally at least alcohol use and illicit drug use decreased due to lower availability111213. With a few exceptions (such as the United Kingdom or North America for alcohol use), the reduction in use has been corroborated by the sales statistics. However, while sales overall went down, certain segments of the population increased their consumption, and a systematic review indicated that people who were drinking heavily before the pandemic increased their drinking during the pandemic, thus contributing to the expected increase in disorders8.

As for the impact of mental and addictive disorders on COVID-19 infections, several large studies in the US1415 and a systematic review16 have indicated that these kinds of disorders are highly associated with COVID-19 infections, both with incidence and course, including fatal outcomes. Stress and impact on the immune system are likely causal pathways for this association1718.

Overall, the evidence points clearly towards an increased burden of mental and substance use disorders during and after the COVID-19 pandemic. We need to prepare our healthcare systems to cope with these phenomena for the coming years1920. Despite the optimism of the World Health Organization (WHO)1, we have an uphill battle ahead us. While universal health coverage, including mental and substance use disorders, is a necessity for economic and ethical reasons21, the current situation is far from having achieved this goal22. Let us hope that the WHO special initiative for mental health (2019-2023): Universal health coverage for mental health23, will bring us at least a few steps closer.