Avoiding a new epidemic during a pandemic: The importance of assessing the risk of substance use disorders in the COVID-19 era

On March 11, 2020, the World Health Organization classified the public health emergency caused by COVID-19 as a pandemic, causing significant changes in people's daily lives and a devastating impact on the economy, accompanied by a profound overhaul of social structures and health systems.

From its expected major impact on mental health, social distance measures imposed worldwide are themselves risk factors for different mental health problems, including suicide and self-harm, alcohol and substance misuse, gambling and domestic/child abuse. Since quarantined people may experience boredom, loneliness, anger, depression, anxiety, despair and insomnia, providers should be alert to potential increases in substance use to alleviate these negative feelings, particularly among vulnerable patients like those with a substance use disorder (SUD). Globally, SUDs are estimated to have a prevalence of 100.4 million persons for alcohol, 22.1 million for cannabis and 26.8 million for opioids (GBD 2016 Alcohol and Drug Use Collaborators, 2018), and social and mental health support is crucial for people trying to recover from SUD, whereas social isolation is a risk factor for relapse. As frequently documented, housing instability as well as reduced access to health care and recovery support services pose an additional challenge in these populations.

Compared to the general population, people with substance use disorders are more likely to have a higher burden of comorbid medical conditions, and it is now well known that people who habitually smoke or vape tobacco and/or cannabis are at particular risk of experiencing more unfavorable outcomes due to the respiratory and pulmonary effects of SARS-CoV2 (Berlin, et al., 2020). Immunocompromised individuals (like those due to HIV infection) also are in increased risk, and a considerable percentage of this population inject drugs. The withdrawal symptoms triggered during social confinement can also end up compromising these measures imposed by governments, leading individuals to leave their homes in search of drugs on the streets, potentially increasing their exposure to the virus.

Being an easily accessible substance, alcohol consumption is often used to cope with negative emotions. Present times of uncertainty may lead to an increase in alcohol misuse, relapse and development of alcohol use disorder. This can lead to physical dependence and a drastic restriction on access to alcohol can lead to life-threatening withdrawal symptoms, as well as an increased risk for domestic violence. Alongside isolation itself, depression and alcohol consumption are risk factors for suicide, which may also be triggered by unemployment and other social/financial stressors. In addition, excessive alcohol consumption may lead to a weakened immune system, increasing a person's susceptibility to pneumonia (Sarkar, et al., 2015), making this population particularly vulnerable to COVID-19.

In order to also deal with anxiety and insomnia during this period, the consumption of other drugs, such as benzodiazepines and cannabis is expected to occur. Although benzodiazepines are legal substances usually prescribed by doctors, they represent a potential for abuse, and their excessive consumption can often go unnoticed. The consumption of these legal drugs is particularly prevalent among elderly patients, who represent the main age-risk group for COVID-19 infection, and it is important to note that the prevalence of SUD in this population has been increasing globally (Kuerbis, et al., 2014). Cannabis abuse has been proposed as a precipitant of psychotic episodes in people with schizophrenia and capable of anticipating the onset of disease development. Potentially aggravated by its chronic use, the so-called cannabis amotivational syndrome refers to lack of motivation, decline in functioning levels and apathy, a condition with a predominance of negative symptoms, which culminates in a state of neglect and divestment in the individual itself.

Drug treatment for opioid use disorders can be immediately effective and life-saving, and is usually provided in an outpatient setting. Since it is a therapy highly regulated by health authorities, people with opioid use disorders may face even greater challenges obtaining opioid agonist treatment, which should be considered an essential treatment during the COVID-19 pandemic (World Health Organization, 2020). Greater flexibility in dispensing take-home medication, such as providing more than one dose of methadone at a time due to restrictions of movement, in combination with isolated consumption, increases vulnerability to relapse and overdose, since there might not be any observers who can administer naloxone to reverse them. There is also evidence of increased burden of respiratory diseases in people who use illicit opioids, making this is group especially vulnerable to the pandemic threat, as there is an increased risk of overdose, since these substances can depress breathing.

In some patients, particularly those with personality disorders, substance use reflects the difficulty in processing feelings of emptiness and abandonment (which may be further aggravated due to quarantine and imposed social isolation), or even the search for a toxic state that promotes an internal elevation of mood, promoting greater harmony and pleasure. These individuals present a behavioral functioning pattern determined by instability and an intensely disruptive psychological conformation, with an underlying hyper-responsiveness to stress. The current pandemic crisis has also led to the interruption of psychotherapeutic support in this population, which may precipitate greater destabilization among these patients on a daily basis, leading to acting-out behaviors, with an increased frequency of drug intoxications and substance consumption.

People who started using drugs as a way to help with their suffering caused by the changes imposed by the pandemic, as well as those who already used them or accessed substance abuse treatment services may be particularly at risk during the current COVID-19 pandemic. Usually, these end up constituting marginalized groups, despite being present in countries of all incomes, so it is urgent that they be taken into account in public health strategies. Thus, considering the worldwide reorganization of mental health services, addiction care must be reinforced, instead of postponed, so clinicians could be aware of signs of substance misuse in these populations, considering the levels of additional stress they may be experiencing. For those with substance use disorders, changes in the ability to access substances and their treatments can precipitate new crises.