Alcohol and Substance Abuse in the General Population during the COVID-19 Pandemic: Results of the COMET-G International Study

The global impact of the COVID-19 pandemic on mental health and substance use behaviors has sparked extensive research efforts. The COMET-G international study, organized by the Department of Medicine and the Rectorate of the Aristotle University of Thessaloniki in collaboration with the World Psychiatric Association, delved into these issues. Running from March 2020 to April 2021, the study collected responses from 55,589 individuals across 40 countries. Through a comprehensive questionnaire, participants provided insights into their mental state, attitudes toward the pandemic, and the resultant changes in their personal and daily lives. Findings revealed, among other things, significant patterns of change in substance use, with notable correlations between reduced usage and the severity of lockdown measures among non-binary individuals. Mental health history emerged as a strong predictor of substance use changes, with influences from anxiety disorders, depression, and self-harm. Additionally, family and social dynamics, including economic expectations and household composition, significantly shaped substance use behaviors during lockdowns. Given these findings, the development of comprehensive approaches targeting the adverse effects of the pandemic on individual behaviors and general welfare is crucial.

The COVID-19 pandemic has resulted in substantial challenges at an international level, affecting various aspects of human existence, including mental health, patterns of substance misuse, and coping mechanisms. An onslaught of research efforts has been prompted by this turbulent environment in an attempt to comprehend its complex effects on human health and behavior. Although previous research has examined the overall impacts of substance use and mental health, there is a notable knowledge gap regarding the precise effects of sociodemographic factors, mental health background, and familial dynamics on fluctuations in alcohol consumption, smoking, and illicit substance use amidst the worldwide health emergency.

The primary objective of the researchers is to highlight any changes in levels of substance use during the pandemic. Secondly, their objective is to ascertain the attributes that can serve as predictors of alterations in said behaviors. A thorough analysis of these components contributes to a more precise comprehension of how individuals navigate the complexities associated with lockdowns, societal disruptions, and the impending economic uncertainties that are linked to the ongoing global health crisis.

Historical data about past pandemics and crises can offer a contextual framework for comprehending the possible transformations in substance utilization amidst periods of adversity. An instance of this can be seen in the correlation between elevated levels of psychological distress and heightened smoking and alcohol consumption during the 2003 SARS outbreak [1-3]. Likewise, inquiries into the consequences of the terrorist attacks that occurred on September 11th unveiled a surge in the consumption of cigarettes, alcohol, and marijuana within the populations that were impacted [4-17].

Moreover, it is widely recognized that there exists a multifaceted relationship between substance use and mental health, whereby individuals frequently turn to substances as a means of managing mental health sequelae [18-21].

The current pandemic is characterized by stressful life experiences, which have been widely acknowledged as significant determinants in shaping patterns of alcohol consumption and substance use [22-29]. There is a suggestion that in response to collective stressors, individuals may adopt coping strategies, which can be positive or negative [30]. While certain individuals may reduce their substance use as a protective mechanism, others may revert to these behaviors as maladaptive coping mechanisms.

To address this disparity, the present study employs the all-encompassing approach described in Fountoulakis, et al. [31]. The primary aim of the current study was to identify any fluctuations in substance use behaviors and, secondly, to canvass predictors and patterns that account for any observed fluctuations. An additional aim of the study was to provide pragmatic knowledge for public health endeavors and interventions that specifically address the adverse consequences of the pandemic on substance addiction and mental health.

Method

The protocol used is referred to in Fountoulakis, et al. [31] and gathered sociodemographic data, data about somatic and mental health history, and data concerning the COVID-19 pandemic including lockdown intensity (Completely, To a high degree, Partially, Not at all). It also included six questions about alcohol use, smoking, and substance abuse as follows:

M1. Smoking before the epidemic (I didn’t smoke/I was smoking)

M2. Alcohol use before the epidemic (I did not drink much/I drank a lot, more than one drink or its equivalent every day)

M3. Use of illegal substances before the epidemic (e.g. hashish) (I did not use it/Occasionally and rather rarely/Often)

M4. During lockdown, you smoke (…) compared to before (More than before/Same as before/Less than before)

M5. During lockdown, you drink alcohol (…) compared to before (More than before/same as before/Less than before)

M6. While isolated at home, you use illegal substances (…) compared to before (More than before/same as before/Less than before)

Depression was assessed with the use of the CES-D [32-34] and anxiety with the STAI-S [35]. The RASS [34] was used to assess suicidality.

The data were collected online and anonymously from April 2020 through March 2021, covering periods of full implementation of lockdowns as well as of relaxations of measures in countries around the world. Announcements and advertisements were made on social media and through news sites, but no other organized effort had been undertaken. The first page included a declaration of consent which everybody accepted by continuing with the participation.

Approval was initially given by the Ethics Committee of the Faculty of Medicine, Aristotle University of Thessaloniki, Greece, and locally concerning each participating country.

The study sample included data from 40 countries concerning 55,589 responses (64.85% females; 34.05% males; 1.10% other) to the online questionnaire. The contribution of each country and the gender and age composition has been published previously as well as details concerning various sociodemographic variables (marital status, education, work, etc.) [31].

The study population was self-selected. It was not possible to apply post-stratification on the sample as it was done in a previous study [33], because this would mean that we would utilize a similar methodology across many different countries and the population data needed were not available for all.

• Chi-square tests were used for the comparison of frequencies when categorical variables were present and for the post hoc analysis of the results a Bonferroni-corrected method of pair-wise comparisons was utilized [36].
• Analysis of Variance (ANOVA) was used to test differences among groups
• Pearson Correlation Coefficient (R) was used to test for relationships between continuous variables
• Multiple forward stepwise linear regression analysis (MFSLRA) was performed to investigate which variables could function as predictors and contribute to the development of others (e.g. depression).

Demographics

The study sample included data from 40 countries. In total responses were gathered from 55,589 participants, aged 35.45 ± 13.51 years old; 36047 females (64.84%; aged 35.80 ± 13.61) and 18927 males (34.05%; aged 34.90 ± 13.29), while 615 declared ‘non-binary gender’ (1.11%; aged 31.64 ± 13.15). One-third of the study sample was living in the country’s capital and an additional almost one-fifth in a city of more than one million inhabitants. Half were married or living with someone while 10.41% were living alone. Half had no children at all and approximately 75% had a bachelor’s degree or higher. In terms of employment, 23.54% were civil servants, 37.06% were working in the private sector, 18.35% were college or university students while the rest were retired or were not working for a variety of reasons; of these, 33.86% did not work during lockdowns. The detailed composition of the study sample has been published in detail previously [31].

The effect of the COVID-19 pandemic on smoking, alcohol and substance abuse

Overall and concerning the total study sample, 21.95% of females, 28.67% of males, and 24.07% of ‘non-binary gender’ reported that they were smoking before the pandemic (24.26% of the total study sample, df = 2, chi-square = 1.387, p = 0.499). The respective rates concerning alcohol abuse were 6.55%, 12.85%, and 17.07 (8.81% of the total study sample, df = 2, chi-square = 4.686, p = 0.096), and concerning illegal substances were 5.61%, 9.71% and 18.05% (7.14% of total study sample, df = 2, chi-square = 7.430, p = 0.024). Concerning substance abuse before the pandemic the difference was specifically significant concerning females vs. ‘nonbinary gender’ (df = 1, chi-square = 6.818, p = 0.009).

Although smoking was increased by some and decreased by others during the lockdown, more people reduced than increased smoking (females 29.29% vs. 9.03%; males 32.54% vs. 10.54%; ‘nonbinary gender’ 35.28% vs. 16.10%; total study sample 30.46% vs. 9.62%). The pattern was similar with alcohol (females 30.88% vs. 10.42%; males 34.64% vs. 11.33%; ‘nonbinary gender’ 26.67% vs. 15.93%; total study sample 32.11% vs. 10.79%) and with substance abuse (females 32.68% vs. 2.12%; males 37.91% vs. 5.70%; ‘nonbinary gender’ 38.37% vs. 12.36%; total study.

Sample 34.52% vs. 3.45%). There was no difference between genders concerning the percentages of reduction (df = 2, chi-square = 0.720, p = 0.868), but there was concerning the increase (df = 2, chi-square = 8.143, p = 0.017), which was due to the difference between females vs. ‘nonbinary gender’ (df = 1, chi-square = 7.680, p = 0.005).

Interestingly, only in ‘non-binary gender’, the degree of lockdown was related to higher reporting of non-smoking (df = 3, chi-square = 20.495, p = 0.001; RR = 1.17-1.41), non-alcohol abuse (df = 3, chi-square = 16.015, p = 0.001; 1.17-1.32) and non-abuse of illegal substances (df = 3, chi-square = 13.094, p = 0.004; 1.11-1.27) before the lockdown.

Only in ‘non-binary gender’, a reduction was related to the degree of lockdown only concerning smoking (df = 3, chi-square = 68.374, p = 0.001; RR = 1.42-1.80) and an increase was inversely related to the degree of lockdown only concerning illegal substance abuse (df = 3, chi-square = 11.509, p = 0.009; RR = 0.25-0.75).

Age correlated weakly but significantly (p < 0.05) with smoking (R = 0.04), alcohol abuse (R = 0.01), and illegal substance use (R = -0.09) before the lockdown. Interestingly advanced age was positively correlated (p < 0.05) with the increase in the use of all substances during the lockdown.

In comparison to no-lockdown, complete lockdown puts the person at approximately RR = 1.4-1.5 times to either increase or decrease smoking, RR = 1.46 to decrease alcohol, and 1.4-1.6 to either increase or decrease illegal substance use.

The detailed results of substance use patterns by gender and lockdown measures presence are shown in Table 1.

Relationship of substance use changes with anxiety, depression, suicidality, and a history of mental health

The complete results concerning mental health during the pandemic will only briefly be mentioned here and are referred to in Fountoulakis, et al. [31]. From the total study sample, 47.41% reported an increase in anxiety, and 40.28% reported an increase in depressive feelings. Suicidal thoughts were increased by 10.83%. Overall, current probable depression was present in 20.49% of females, 12.36% of males, and 27.64% of those registered as ‘non-binary gender’, with an unweighted average of 17.80% for the whole study sample. Additionally, distress was present in 17.41%, 15.17%, 23.09%, and 16.71% respectively. Also, 4.80% reported that they often thought much or very much about committing suicide if they had the chance.

In terms of mental health history and self-harm, 7.85% had a prior history of an anxiety disorder, 12.57% of depression, 1.16% of Bipolar disorder, 0.97% of psychosis and 2.70% of other mental disorders. Any mental disorder history was present in 25.25%. At least once, 21.44% had hurt themselves in the past and 10.59% had attempted at least once in the past.

There was no difference among the diagnostic groups of ‘no depression or dysphoria’ vs. ‘dysphoria’ vs. ‘clinical depression’ in terms of smoking (df = 2, chi-square = 0.320, p = 0.852), alcohol abuse (df = 2, chi-square = 0.667, p = 0.716) or illegal substance abuse (df = 2, chi-square = 3.388, p = 0.183) before the lockdown. There was no difference among the diagnostic groups concerning the rates of increase or decrease in smoking and alcohol or substance abuse.

The detailed results of substance use patterns, before and during the COVID-19 lockdown, by gender and depression clinical group are shown in Table 2.

The presence of a history of mental health acted as an important risk factor for substance use. The highest RR for smoking and alcohol abuse before the lockdown concerned a history of psychosis (RR = 1.60 and 2.87). History of Bipolar disorder (RR = 1.51 and 1.83) history of suicidal attempts (RR = 1.43 AND 2.57) and self-harm (RR = 1.29 and 2.04) were also strong risk factors. The strongest risk factors for illegal substance use before the lockdown were mainly psychosis (RR = 3.57), suicidal attempt (RR = 4.02), and Bipolar disorder (RR = 3.55). The strongest risk factors for an increase in smoking during the lockdown were Psychosis (RR = 2.22), Bipolar disorder (RR = 2.19), and suicidal attempt (RR = 2.18) while concerning the increase in alcohol abuse were any mental disorder (RR = 1.74), Bipolar disorder (1.83) and suicidal attempt (RR = 1.72). History of Psychosis (RR = 3.29), Bipolar disorder (RR = 3.18), and suicidal attempt (RR = 3.92) were the strongest factors for an increase in illegal substance use during the lockdown.

The complete set of RRs concerning the effect of a history of mental disorders on substance use is shown in Table 3.

Relationship of substance use changes with the family and social environment

In terms of family status, 43.95% were married, 48.53% had at least one child and only 10.41% were living alone. The responses suggested an increased need for communication with family members in 38.08%, an increased need for emotional support in 26.22%, fewer conflicts in 34.81% and increased conflicts within families for 37.71%, an improvement of the quality of relationships in 23.95%, while in most cases (61.62%) there was a maintenance of basic daily routine. During lockdowns, 33.86% did not work, while 48.43% expected their economic situation to worsen because of the COVID-19 outbreak.

Pearson’s R among the number of people living in the house returned a significant but weak negative correlation (R = -0.11 to -0.13) with all smoking alcohol and substance use variables reflecting change during lockdown, reflecting an increase of use in crowded households. On the contrary, the number of children was significantly but weakly and positively correlated (R = 0.017 to 0.058) with all smoking alcohol and substance use variables reflecting change during lockdown, suggesting a decrease of use in families with many children. Education was also weakly protective (R = 0.02 to 0.05).

Multiple forward stepwise linear regression analysis

MFSLRA was performed with each one of the three items reflecting smoking, alcohol, and substance use change items as dependent variables and gender (three dummy variables males, females, and ‘non-binary’ gender as yes/no), age, number of persons in the house, number of children, presence of chronic somatic condition, being a caretaker, lockdown intensity, history of specific mental disorders (in separate variables), CES-D, STAI-S and RASS subscales scores (Intention, life, and history subscales). Although the results were significant, the regressions explained only approximately 4% of the observed variance.

• Change in smoking was significantly predicted (F = 129.907, R-sqr = 0.04, df: 18,54806; p < 0.001) by age (b = -0.01), number of people at home (b = -0.15), number of children (b = 0.68), being a caretaker (b = 0.06), lockdown intensity (b = -0.02), STAI-S (b = -0.02), CES-D (b = -0.03), RASS Life (b = 0.09), RASS History (b = -0.04), history of psychosis (b = 0.01), history of depression (b = 0.02), history of other mental disorder (b = 0.02), history of self-harm (b = 0.05) and history of suicide attempts (b = 0.02).

• Change in smoking was significantly predicted (F = 129.907, R-sqr = 0.04, df: 18,54806; p < 0.001) by age (b = -0.01), number of people at home (b = -0.15), number of children (b = 0.68), being a caretaker (b = 0.06), lockdown intensity (b = -0.02), STAI-S (b = -0.02), CES-D (b = -0.03), RASS Life (b = 0.09), RASS History (b = -0.04), history of psychosis (b = 0.01), history of depression (b = 0.02), history of other mental disorder (b = 0.02), history of self-harm (b = 0.05) and history of suicide attempts (b = 0.02).
• Change in alcohol consumption was significantly predicted (F = 138.984, R-sqr = 0.04, df: 16,54808; p < 0.001) by male gender (b = -0.01), non-binary gender (b = 0.01), number of people at home (b = -0.13), number of children (b = 0.09), being a caretaker (b = 0.06), suffering from a chronic somatic condition (b = -0.009), lockdown intensity (b = -0.03), STAI (b = -0.03), CES-D (b = -0.04), RASS Life (b = 0.08), RASS Intention (b = 0.02), history of anxiety (b = 0.01), history of depression (b = 0.2), history of other mental disorder (b = 0.2), and history of self-harm (b = 0.02).
• Change in illegal substance use was significantly predicted (F = 117.031, R-sqr = 0.04, df: 18,54806; p < 0.001) by male gender (b = -0.02), age (b = -0.03), number of people at home (b = -0.11), number of children (b = 0.04), being a caretaker (b = 0.06), lockdown intensity (b = -0.02), STAI-S (b = -0.05), CES-D (b = -0.08), RASS Life (b = 0.10), RASS Intention (b = 0.01), RASS History (b = -0.04), history of psychosis (b = 0.02), history of anxiety (b = 0.008), history of depression (b = 0.01), history of Bipolar disorder (b = 0.009), history of other mental disorder (b = 0.01), history of self-harm (b = 0.04) and history of suicide attempts (b = 0.02).

Before the COVID-19 pandemic outbreak, the percentage of those who smoked cigarettes was 24.26%, those who abused alcohol were 8.81%, and those who used illegal substances were 7.14% in the overall study population. The impact of lockdown measures on substance use was variable, as a greater proportion of respondents indicated a decrease in alcohol, nicotine, and substance abuse rather than an increase. Complete lockdown put the person at an approximately RR = 1.5 times to either increase or decrease substance use. Similar findings have been described in other studies [37,38]. Potential determinants of this variability could encompass fluctuations in social interactions, heightened levels of stress, modified routines, and psychological health difficulties encountered throughout periods of lockdown. Certain individuals may resort to substance use as a means of managing difficulties [39], whereas others may decrease their use in response to access disruptions or shifts in social dynamics [40,41].

The prevalence of smoking decreased varied across gender groups. Similarly, the proportions of alcohol and illicit substance use reduction spanned from 32.11% to 34.52%. The aforementioned figures are consistent with the findings of several research studies [39,41-48]. These findings suggest that the ongoing crisis has, to a certain degree, prompted favorable modifications in substance use patterns. However, a multitude of studies propose an alternative perspective [37,38,40,49-58]. These contrasts may be attributed to differences in study methodologies, distinctions in study participant demographics, and the diverse stages of quarantine that were examined.

It is worth mentioning that individuals who self-identified as “non-binary gender” demonstrated greater reductions in substance use during the lockdown. Significantly, a discernible correlation was identified among non-binary individuals between the severity of confinement protocols and a reduction in the consumption of all substances. This may underscore the criticality of taking into account a wide range of sociodemographic variables [59]. Non-binary individuals frequently confront social structures and norms that contest the conventional binary conception of gender. Engaging in this process of navigating societal expectations and stereotypes has the potential to foster the growth of resilience and coping mechanisms, which in turn may have an impact on patterns of substance use. The consensus among researchers regarding LGBTQ+ communities as a whole indicates that minority stress and discrimination are correlated with a heightened likelihood of engaging in substance use [60]. Nevertheless, non-binary individuals may also benefit from specialized support networks, community resilience, and coping mechanisms that may aid in the reduction of substance abuse. Conversely, alternative research has indicated that women are more likely to endorse proactive strategies in the face of challenges associated with COVID-19 [45,61].

Before the lockdown, there was a faint negative correlation between advanced age and reductions in smoking, alcohol abuse, and illegal substance use. Advanced age was positively correlated with the increase in the use of all substances during the lockdown. A plausible hypothesis is that elderly individuals may encounter difficulties acclimating to abrupt transformations in their lives, including diminished social interactions, restricted availability of support systems, and heightened experiences of isolation or ennui. As a consequence, certain individuals may have resorted to illicit substances such as cigarettes, alcohol, or drugs to alleviate emotional distress and manage stress, although findings from different studies are non-decisive [41,43,52,59].

Before the lockdown, individuals with a documented history of mental health disorders including psychosis, bipolar disorder, and suicidal ideation exhibited the most pronounced correlations with substance use. Anxiety (as measured by the STAI-S scale), depressive symptoms (as measured by the CES-D scale), and suicidality (as measured by the RASS subscale) were all significant predictors of changes in smoking, alcohol consumption, and illicit substance use throughout the pandemic. A rise in anxiety and depressive symptoms was observed in 40.28% and 47.41% of the participants, respectively. One in 10.83% of respondents indicated that they had suicidal thoughts. The incidence of depression exhibited variability among non-binary individuals, males, and females, comprising 20.49%, 12.36%, and 27.64%, respectively. There is substantial evidence of the reciprocal relationship between substance use disorders and psychiatric conditions [62-65]. Acknowledging the cyclical nature of their relationship assists in highlighting the critical importance of integrated mental health and substance use interventions, as well as the profound impact that external stressors have on mental health. Buckner, et al. (2007) [66] have proposed that individuals may resort to self-regulating behaviors such as alcohol or nicotine use to momentarily ameliorate stress and tension due to the overwhelming nature of anxiety. Furthermore, according to the self-medication hypothesis [67], depressed individuals might self-medicate with substances in an attempt to alleviate feelings of hopelessness or sadness. In addition, as a means of coping with the distressing nature of these emotions, individuals who are facing suicidal ideation or behavior may resort to substance use. Nevertheless, it is imperative to acknowledge that substance use may also constitute an independent suicide risk factor [68].

The exploration of further sociodemographic variables yielded intricate understandings of how economic considerations, family structure, and work-related interactions influenced substance use patterns during lockdowns. The participants documented an increased need for emotional support and communication, as well as changes in conflicts and the overall standard of interpersonal connections. Further factors that were taken into account were the employment status and the number of occupants in the household. The employment status exhibited a marginally negative correlation with substance use behaviors during the lockdown period, while the former did indeed contribute to such changes. A substantial majority of respondents expected a deterioration in the economy as a direct outcome of the pandemic. The influence of the social environment has been underscored by a negative correlation observed between congested households and increased substance use [44,69]. Kassel, Veilleux, Wardle, and Markowitz [70] have also proposed a correlation between substance abuse and overcrowding in living quarters. The pressure associated with cohabitating in a small area with a large number of people may potentially lead some individuals to turn to substances as a coping mechanism or source of solace. Nevertheless, one could argue that the frequency of alcohol consumption or alcohol dependence does not exhibit a direct cause-and-effect relationship with loneliness amidst the COVID-19 pandemic.

Conversely, there was a marginal yet statistically significant positive correlation between the number of children residing in a household and a decrease in smoking, alcohol usage, and illicit substance use throughout the lockdown period. This finding implies the possibility of a protective effect. According to research, after having children, parents frequently adopt protective behaviors because they place a higher value on their children’s safety than on engaging in hazardous activities. According to a study by Latendresse, et al. [71], to provide a secure and nurturing atmosphere for their children, parents are more likely to desist from or reduce their substance use, with mothers being particularly likely to do so. In addition, the cohabitation of children within the household may foster stronger social support systems, as parents work together in concert to address the difficulties presented by the lockdowns. A correlation has been established between social support and reduced substance use [72]. Furthermore, the shared obligation of child care may cultivate an atmosphere in which parents proactively discourage substance use to preserve a stable and healthy household. It has been suggested that health factors and greater social proximity to non-smokers may provide a preventative effect against the use of cigarettes [45,73].

Additionally, education exhibited a feeble protective effect. The protective effects of higher education suggest that education may serve as a buffer against the detrimental effects of substance use-inducing stressors. This result is consistent with previous research [30] that highlighted the importance of education in fostering health literacy and adaptive coping mechanisms. Individuals who have attained higher levels of education may possess enhanced capabilities to evaluate the hazards critically linked to substance use, thereby decreasing the probability of their involvement in such behaviors. However, the results of the research are not unanimous [39].

The changes in substance use behaviors that have been observed throughout the pandemic emphasize the significance of situating these behaviors in a wider framework of individuals’ lives. Due to the complex interaction between sociodemographic variables, mental health indicators, and environmental influences, targeted and individualized interventions seem essential. As society confronts the intricate challenges of public health in the aftermath of a global health crisis, the insights gained and the lessons learned provide significant value for the development of such evidence-based approaches. Approaches that consider various reactions to stressors, foster mental health and avert harms associated with substance use during critical periods. Notwithstanding the importance of specific predictors, the restricted explanatory variance implies the presence of latent variables or dynamic interactions that could potentially exert pivotal influences. Capturing the complete range of factors that influence various types of substance use presents a significant challenge, which requires continuous research to improve predictive models and interventions.

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