Epigenetic drugs and psychedelics as emerging therapies for alcohol use disorder: insights from preclinical studies

Alcohol use disorder (AUD) is a public health issue that affects millions of people worldwide leading to physical, mental and socio-economic consequences. While current treatments for AUD have provided relief to individuals, their effectiveness on the long term is often limited, leaving a number of affected individuals without sustainable solutions. In this review, we aim to explore two emerging approaches for AUD: psychedelics and epigenetic drugs (i.e., epidrugs). By examining preclinical studies, different animal species and procedures, we delve into the potential benefits of each of these treatments in terms of addictive behaviors (alcohol drinking and seeking, motivation to drink alcohol and prevention of relapse). Because psychedelics and epidrugs may share common and complementary mechanisms of action, there is an exciting opportunity for exploring synergies between these approaches and their parallel effectiveness in treating AUD and the diverse associated psychiatric conditions.

Classic psychedelics and alcohol use disorders: A systematic review of human and animal studies

Classic psychedelics refer to substances such as lysergic acid diethylamide (LSD), psilocybin, ayahuasca, and mescaline, which induce altered states of consciousness by acting mainly on 5-HT_2A receptors. Recently, the interest of psychedelics as pharmacological treatment for psychiatric disorders has increased significantly, including their use on problematic use of alcohol. This systematic review is aimed to analyse the last two decades of studies examining the relationship between classic psychedelics and alcohol consumption. We searched PubMed and PsycInfo for human and preclinical studies published between January 2000 to December 2021. The search identified 639 publications. After selection, 27 studies were included. Human studies (n = 20) generally show promising data and seem to indicate that classic psychedelics could help reduce alcohol consumption. Nevertheless, some of these studies present methodological concerns such as low number of participants, lack of control group or difficulty in determining the effect of classic psychedelics in isolation. On the other hand, preclinical studies (n = 7) investigating the effect of these compounds on voluntary alcohol consumption are scarce and show some conflicting data. Among these compounds, psilocybin seems to show the most consistent data indicating that this compound could be a potential candidate to treat alcohol use disorders. In the absence of understanding the biological and/or psychological mechanisms, more studies including methodological quality parameters are needed to finally determine the effects of classic psychedelics on alcohol consumption.

Past-year hallucinogen use in relation to psychological distress, depression, and suicidality among US adults

BACKGROUND

There is renewed interest in the clinical application of hallucinogenic substances to treat a range of psychiatric conditions. However, there is mixed evidence regarding how use of such substances outside of medical settings relates to psychological distress, depression, and suicidality.

METHODS

We examined data from a US representative sample of noninstitutionalized adults from the 2015-2020 National Survey on Drug Use and Health (N = 241,675). We evaluated whether past-year use of specific hallucinogens (i.e., LSD, DMT/AMT/Foxy, salvia divinorum, ecstasy [MDMA/Molly], ketamine) is associated with reporting past-year serious psychological distress (SPD), major depressive episode (MDE), and suicidality. Generalized linear models using Poisson and log link were used to estimate adjusted prevalence ratios (aPRs), controlling for sociodemographic characteristics and past-year use of various other illegal drugs.

RESULTS

LSD use was associated with an increased likelihood of MDE (aPR = 1.23, 95% CI: 1.10-1.37) and suicidal thinking (aPR = 1.21, 95% CI: 1.09-1.34). Similar associations were observed between salvia divinorum use and suicidal thinking (aPR = 1.41, 95% CI: 1.00-1.97) and between DMT/AMT/Foxy use and suicidal planning (aPR = 1.81 95% CI: 1.17-2.81). On the other hand, ecstasy use was associated with a decreased likelihood of SPD (aPR = 0.83, 95% CI: 0.77-0.89), MDE (aPR = 0.91, 95% CI: 0.83-1.00), and suicidal thinking (aPR = 0.86, 95% CI: 0.75-0.99).

CONCLUSION

Findings suggest there are differences among specific hallucinogens with respect to depression and suicidality. More research is warranted to understand consequences of and risk factors for hallucinogen use outside of medical settings among adults experiencing depression or suicidality.

Race, Ethnic, and Sex Differences in Prevalence of and Trends in Hallucinogen Consumption Among Lifetime Users in the United States Between 2015 and 2019

Background

The current study is one of the first to examine race, ethnic, and sex differences in the prevalence of and trends in hallucinogen use among lifetime users in the United States.

Methods

Data came from the 2015-2019 National Survey on Drug Use and Health and included respondent's reporting ever-using hallucinogens (n = 41,060; female = 40.4%). Descriptive and multinomial logistic regression analyses were conducted in Stata.

Results

Highest prevalence of past year hallucinogen use was among Asian females (35.06%), which was two-or-more times larger than prevalence of past year use among White males/females and Native American males. More than half of White males/females, Multiracial males, and Hispanic males reported had ever-used psilocybin or LSD, whereas less than one-quarter of Black males/females reported lifetime psilocybin use, and less than a third of Black females reported lifetime LSD use. Native American males had the lowest prevalence of lifetime MDMA use (17.62-33.30%) but had the highest lifetime prevalence of peyote use (40.37-53.24%). Pacific Islander males had the highest prevalence of lifetime mescaline use (28.27%), and lifetime DMT use was highest among Pacific Islander males/females (15.68-38.58%). Black, Asian, and Multiracial people had greater odds of past-year (ORs = 1.20-2.02; ps < 0.05) and past-month (ORs = 1.39-2.06; ps < 0.05) hallucinogen use compared to White people. Females had lower odds of past-year (OR = 0.79; ps < 0.05), past-month (OR = 0.78; ps < 0.05) hallucinogen use compared to males, except for lifetime use of MDMA (OR = 1.29; ps < 0.05).

Conclusions

These findings should inform public health initiatives regarding potential benefits and risks of hallucinogen use among racial/ethnic groups and women.

Toward a typology of hallucinogen users in the United States

BACKGROUND

Roughly one in ten American adults have used hallucinogens, and emerging evidence suggests that the prevalence of use is increasing. However, our understanding of the degree to which individuals "specialize" in the use of a particular hallucinogen or are poly-hallucinogen users remains incomplete.

METHODS

This study examined data from 6381 individuals reporting past-year hallucinogen use in the 2016-2018 National Survey on Drug Use and Health. Logistic regression examined the association between the number of distinct hallucinogens used and psychosocial/behavioral risks, and latent class analysis (LCA) characterized subgroups of hallucinogen users.

RESULTS

The vast majority of hallucinogen users, roughly 70%, are not "specialists" who use only one hallucinogen type; rather, lifetime poly-hallucinogen use is the norm. Critically, however, we also see that important differences exist within the population of hallucinogen users-half (51%) could be classified as LSD-Mushroom-Ecstasy users only (this group was disproportionally comprised of youth), nearly one third (30%) were Poly-Hallucinogen users (this group was disproportionately male and non-Hispanic White), and smaller proportions were limited primarily to use of LSD-Mushrooms (6%; these individuals were almost exclusively ages 35 and older) or Ecstasy Only (12%; these individuals were mostly younger adults ages 18-34).

CONCLUSIONS

Findings provide a fresh contribution to our understanding of poly-hallucinogen use in a time in which local and state governmental leaders, and people across the country, weigh the benefits and drawbacks of legalizing specific hallucinogenic drugs.

New Insights Into the Clinical and Nonclinical Effects of Psychedelic Substances

Abstract. After decades of stagnation, research on psychedelic substances (such as lysergic acid diethylamide [LSD], psilocybin, or N,N-dimethyltryptamine [DMT]) has experienced a renaissance over the last 10 years, with various major research programs being conducted across Europe and the United States. This research primarily investigates the potential of psychedelics in the treatment of mental health disorders, their short- and long-term effects on recreational users, and the neurological and cognitive processes responsible for their effects. The present review provides a concise summary of the most recent insights gained from this research. We briefly outline the history of psychedelic research, the objective and subjective effects caused by these substances, the prevalence and socio-psychological correlates of their use, as well as their potential for harm. Subsequently, we review empirical research on the beneficial effects of psychedelics in clinical samples, focusing on their efficacy in the treatment of major depression, anxiety, and substance use disorders, and discuss research on the proposed neural and cognitive mechanisms behind these effects. We then review research on their effects on healthy subjects, focusing on psychological well-being as well as changes in personality, nature-relatedness, and creativity. Finally, we review empirical evidence regarding the long-term effects of single experiences with psychedelics and conclude with a summary and outlook.

LSD use in the United States: Trends, correlates, and a typology of us

BACKGROUND

Recent years have witnessed an increased interest in LSD. This study investigates current information on the trends and correlates of LSD use from years 2002-2018 and seeks to develop an initial typology of use and misuse.

METHODS

Data is taken from the NSDUH (National Survey on Drug Use and Health) collected between 2002 and 2018 and trends and correlates of LSD use were analyzed with a survey adjusted logistic regression.

RESULTS

Our findings indicate that LSD use has increased 200 % over the study period (.23 % 2002-2005 to .72 % 2015-2018, AOR = 1.10, 95 % CI = 1.08, 1.12). Our findings also indicate several correlates of LSD use including higher levels of education (college degrees: AOR = 1.62, 95 % CI = 1.23, 2.13), not being married (divorced or separated, AOR = 2.31, 95 % CI = 1.44, 3.73, and have never been married, AOR = 5.67, f 95 % CI = 4.09, 7.86), as well as higher levels of antisocial behavior (having been arrested AOR = 3.20, 95 % CI = 2.50, 4.09) and comorbid mental health and substance abuse disorders (serious psychological distress, AOR = 2.39, 95 % CI = 2.05, 2.80). Further, four distinct subclasses were also discovered within LSD users and two of these subtypes of LSD users contained comorbid mental health disturbances and heavy involvement in the criminal justice system.

CONCLUSION

LSD use has been on the rise within the last decades, particularly among those who are well educated. Two subclasses of LSD use (those with severe comorbid mental health disorders and those with criminal justice involvement) may require further interventions.

On the Relationship between Classic Psychedelics and Suicidality: A Systematic Review

Use of classic psychedelics (e.g., psilocybin, ayahuasca, and lysergic acid diethylamide) is increasing, and psychedelic therapy is receiving growing attention as a novel mental health intervention. Suicidality remains a potential safety concern associated with classic psychedelics and is, concurrently, a mental health concern that psychedelic therapy may show promise in targeting. Accordingly, further understanding of the relationship between classic psychedelics and suicidality is needed. Therefore, we conducted a systematic review of the relationship between classic psychedelics (both non-clinical psychedelic use and psychedelic therapy) and suicidality. We identified a total of 64 articles, including 41 articles on the association between non-clinical classic psychedelic use and suicidality and 23 articles on the effects of psychedelic therapy on suicidality. Findings on the association between lifetime classic psychedelic use and suicidality were mixed, with studies finding positive, negative, and no significant association. A small number of reports of suicide and decreased suicidality following non-clinical classic psychedelic use were identified. Several cases of suicide in early psychedelic therapy were identified; however, it was unclear whether this was due to psychedelic therapy itself. In recent psychedelic therapy clinical trials, we found no reports of increased suicidality and preliminary evidence for acute and sustained decreases in suicidality following treatment. We identify some remaining questions and provide suggestions for future research on the association between classic psychedelics and suicidality.

Trends in LSD use among US adults: 2015-2018

BACKGROUND

The recent use of LSD to treat severe psychological disorders in several clinical applications has proven effective in reducing symptoms and distressing events. Trend analyses are warranted to provide the most current data for clinical and health interventions. The purpose of this study was to examine trends in LSD use among adults in the United States.

METHODS

A secondary analysis of the 2015-2018 National Survey on Drug Use and Health was conducted on 168, 562 adults ages 18 and older.

RESULTS

Past-year LSD use increased 56.4% (P < .0001) from 2015 to 2018. The proportion of LSD users ages 26-34 increased from 19.6% to 31.1% (P < .0001), ages 35-49 increased from 2.73% to 8.82% (P < .0001) and 50 years or older increased from 1.83% to 2.66% (P < .0001). LSD use among bisexual individuals increased from 11.2% to 13.0% (P < .0001). LSD use among individuals with a college degree or more increased from 18.2% to 31.1% (P < .0001). Significant decreases in LSD use were present in individuals who were multi-racial (P < .0001), less than high school education P < .0001), high school education (P < .001), and perceived great risk of drugs (P < .0001).

CONCLUSIONS

LSD use in the US jumped 56.4% from 2015 to 2018. Results from the present study can inform prevention and harm reduction efforts (e.g., co-morbid substance use interventions, health messaging).

Psychosocial Correlates and Early Substance Abuse Associated With Lifetime Hallucinogen Use Among Hispanic Young Adults

INTRODUCTION

The Hispanic population is among the most rapid growing populations in the United States. Continued research is needed regarding factors associated with substance abuse and Hispanic individuals. The present study examined psychosocial correlates to lifetime hallucinogen use among a national sample of Hispanic adults.

METHOD

A secondary analysis of the 2017 National Survey on Drug Use and Health was conducted. Questions assessing previous lifetime substance use, psychosocial factors, and demographics were completed by 2,866 Hispanic adults. Weighted logistic regression analyses were used to identify significant predictors of lifetime hallucinogen use.

RESULTS

Results indicated that greater than one in seven (15.1%) of Hispanic adults reported having ever used hallucinogens (lifetime use). Findings from the final multivariate regression revealed that those most likely to report lifetime hallucinogen use were male, used alcohol, marijuana, cigars, cigarettes, inhalants, and cocaine before the age of 21, and binge drank in the past 30 days.

DISCUSSION

Culturally competent prevention strategies aimed at addressing hallucinogen use among Hispanics are needed. Further research studies examining psychosocial reasons explaining the high prevalence of hallucinogen use among this population are warranted.