Limited psychological and social effects of lifetime cannabis use frequency: Evidence from a 30-year community study of 4,078 twins.

BACKGROUND: Cannabis use is associated with outcomes like income, legal problems, and psychopathology. This finding rests largely on correlational research designs, which rely at best on statistical controls for confounding. Here, we control for unmeasured confounders using a longitudinal study of twins. METHOD: In a sample of 4,078 American adult twins first assessed decades ago, we used cotwin control mixed effects models to evaluate the effect of lifetime average frequency of cannabis consumption measured on substance use, psychiatric, and psychosocial outcomes. RESULTS: On average, participants had a lifetime cannabis frequency of about one to two times per month, across adolescence and adulthood. As expected, in individual-level analyses, cannabis use was significantly associated with almost all outcomes in the expected directions. However, when comparing each twin to their cotwin, which inherently controls for shared genes and environments, we observed within-pair differences consistent with possible causality in three of the 22 assessed outcomes: cannabis use disorder symptoms (ßW-Pooled = .15, SE = .02, p = 1.7 × 10-22), frequency of tobacco use (ßW-Pooled = .06, SE = .01, p = 1.2 × 10-5), and illicit drug involvement (ßW-Pooled = .06, SE = .02, p = 1.2 × 10-4). Covariate specification curve analyses indicated that within-pair effects on tobacco and illicit drug use, but not cannabis use disorder, attenuated substantially when covarying for lifetime alcohol and tobacco use. CONCLUSIONS: The cotwin control results suggest that more frequent cannabis use causes small increases in cannabis use disorder symptoms, approximately 1.3 symptoms when going from a once-a-year use to daily use. For other outcomes, our results are more consistent with familial confounding, at least in this community population of twins. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Evaluating substance use outcomes of recreational cannabis legalization using a unique co-twin control design.

Background: As more states pass recreational cannabis legalization (RCL), we must understand how RCL affects substance use.Objectives: The current study aims to examine the effect of RCL on lifetime and past-year use of cannabis, alcohol, tobacco, and other drugs, frequency of cannabis, alcohol, and tobacco use, co-use of cannabis with alcohol and tobacco, and consequences from cannabis and alcohol use.Methods: We used a unique, co-twin control design of twin pairs who were discordant for living in a state with RCL between 2018 and 2021. The sample consisted of 3,830 adult twins (41% male), including 232 twin pairs discordant for RCL. Problems from alcohol and cannabis use were assessed via the Brief Marijuana Consequences Questionnaire and the Brief Young Adult Alcohol Consequences Questionnaire.Results: Results indicated that the twin living in an RCL state was more likely to endorse past-year cannabis use (OR = 1.56, p = .009), greater number of cannabis use days in the past 6 months (ß = 0.47, p = .019), but not more negative consequences from cannabis use (ß = 0.21, p = .456) compared to their co-twin in a non-RCL state. There were no differences within-twin pairs in frequency of alcohol use (ß=-0.05, p = .601), but the RCL twin reported fewer negative consequences from alcohol use (ß=-0.29, p = .016) compared to their co-twin in a non-RCL state. We did not observe any other differences within-twin pairs on other outcomes.Conclusion: These results suggest that living in an RCL state is associated with greater cannabis frequency but not more negative consequences from cannabis use than living in a non-RCL state.

Impacts of recreational cannabis legalization on cannabis use: a longitudinal discordant twin study.

AIMS: To estimate the effect of recreational legalization on cannabis use frequency and sources of variance across legal environments. DESIGN: Longitudinal discordant twin and gene-environment interaction models in twins recruited from birth records and assessed prospectively. SETTING: The United States, including states with different recreational cannabis policies before and after 2014, when recreational cannabis was first legalized. PARTICIPANTS: Two longitudinal, prospectively assessed samples of American twins aged 24-47 (n = 1425 in legal states, n = 1996 in illegal states), including 111 monozygotic pairs discordant for residence. MEASUREMENTS: Current cannabis use frequency (measured continuously and ordinally) was the primary outcome, and the predictor was recreational status of cannabis (legal/illegal) in the participant's state of residence at the time of assessment. Covariates include age, sex and cannabis use frequency prior to 2014. FINDINGS: Accounting for pre-2014 use, residents of legal states used cannabis more frequently than residents of illegal states (b = 0.21, P = 8.08 × 10-5 ). Comparing 111 pairs of monozygotic twins discordant for residence confirmed the effect (b = 0.18, P = 0.014). There was inconclusive evidence for genetic influences on cannabis use frequency that were specific to the legal environment [χ2  = 2.9 × 10-9 , degrees of freedom (d.f.) = 1, P > 0.999]. Existing genetic influences were moderated by the legal environment, as the genetic correlation between marijuana use before and after legalization was lower in states that legalized (rgenetic  = 0.24) compared with states that did not (rgenetic  = 0.78, Pdifference  = 0.016). CONCLUSIONS: In the United States, there appears to be a ~ 20% average increase in cannabis use frequency attributable to recreational legalization, consistent across increasingly rigorous designs. In addition, the heritability of cannabis use frequency appears to be moderated by legalization.

Opioid and non-opioid utilization at home following gastrointestinal procedures: a prospective cohort study.

BACKGROUND: Overprescribing of opioid medications for patients to be used at home after surgery is common. We sought to ascertain important patient and procedural characteristics that are associated with low versus high rates of self-reported utilization of opioids at home, 1-4 weeks after discharge following gastrointestinal surgery. METHODS: We developed a survey consisting of questions from NIH PROMIS tools for pain intensity/interference and queries on postoperative analgesic use. Adult patients completed the survey weekly during the first month after discharge. Using regression procedures we determined the patient and procedure characteristics that predicted high post-discharge opioid use operationalized as 75 mg oral morphine equivalents/50 mg oxycodone reported taken. RESULTS: The survey response rate was 86% (201/233). High opioid use was reported by 52.7% of patients (106/201). Median reported intake of opioid pain pills was 7 for week #1 and 0 for weeks #2-4. Combinations of acetaminophen and non-steroidal and anti-inflammatory drugs were used by 8.9%-12.5% of patients after discharge. Following adjustment for significant variables of the univariate analysis, last 24-h in-hospital opioid intake remained as a significant co-variate for post-discharge opioid intake. CONCLUSIONS: After gastrointestinal surgery, the equivalent of each oxycodone 5 mg tablet taken in the last 24 h before discharge increases the likelihood of taking the equivalent of > 10 oxycodone 5 mg tablets by 5%. Non-opioid analgesia was utilized in less than half of the cases. Maximizing non-opioid analgesic therapy and basing opioid prescriptions on 24-h pre-discharge opioid intake may improve the quality of post-discharge pain management.

Cannabis Oil Use by Adolescents and Young Adults With Inflammatory Bowel Disease.

OBJECTIVES: The aim of the study was to describe use of oral or sublingual cannabis oil (CO) by adolescent and young adult patients with inflammatory bowel disease (IBD). METHODS: A descriptive study of IBD patients 13 to 23 years of age seen between January 2015 through December 2017 at Children's Hospital Colorado. Information obtained included chart abstraction, electronic and interview self-report, and serum cannabinoid levels. We compared CO users and cannabis non-users for clinical characteristics and perceptions of risk. Users of CO provided information on routes, patterns, motivations, and perceived benefits and problems with use. RESULTS: The 15 users and 67 non-users were similar for clinical characteristics and pain and appetite scores. 9 of 15 (60%) CO users had used in the past 30 days, an average of 22 ±â€Š9 times; and 4 used daily. A variety of strengths and CBD:THC ratios were reported. Most common perceived effect of use was on sleep quality, nausea, and increase in appetite. Of the 15 users, 6 used only CO and no additional forms of cannabis. Of these 6 CO only users, 5 reported a medical reason for use, most commonly to relieve pain. CONCLUSIONS: Adolescent and young adults with IBD used oral CO and many used other cannabis products as well. Users perceived some medical benefit. Care teams should strive for open communication about use until further information on safety and efficacy becomes available.

Changes in Healthcare Encounter Rates Possibly Related to Cannabis or Alcohol following Legalization of Recreational Marijuana in a Safety-Net Hospital: An Interrupted Time Series Analysis.

OBJECTIVES: Liberalization of marijuana laws in Colorado contributed to increases in cannabis-related adverse events over time. We examined characteristics of patients with healthcare encounters possibly related to cannabis and assessed the temporal association between legalization of recreational marijuana and healthcare encounters possibly attributed to cannabis. METHODS: Annual encounter rates possibly related to cannabis and alcohol were compared using negative binomial regression. Two-time intervals, pre/post-recreational marijuana legalization (January 2009 to December 2013 and January 2014 to December 2015, respectively) were used to examine changes in monthly rates of emergency encounters and hospitalizations possibly related to cannabis. Level and trend changes on encounter rates by legalization period were assessed using interrupted time series analyses. Encounters possibly related to alcohol were used as a comparator group. RESULTS: Most encounters identified during the study period had alcohol-related International Classification of Diseases Diagnosis and Procedural Codes (ICD-9/10-CM) codes (94.8% vs 5.2% for cannabis). Patients with encounters possibly related to cannabis were younger, more likely to be hospitalized and more likely to be admitted to the psychiatric unit than patients with encounters possibly related to alcohol. Initial and sustained effects of encounter rates possibly related to cannabis demonstrated an increased trend in slope before and after recreational marijuana legalization. The slope became more abrupt following legalization with a significant increase in trend during the post-legalization period (ß = 2.7, standard error = 0.3, ρ < 0.0001). No significant change was noted for encounters possibly related to alcohol. CONCLUSIONS: Additional research should identify patients at highest risk of an adverse health event related to cannabis and quantify costs associated with cannabis-related healthcare delivery.

The Association of Patient Satisfaction-Based Incentives with Primary Care Physician Opioid Prescribing.

PURPOSE: The opioid epidemic in the United States is an ongoing public health concern. Health care institutions use standardized patient satisfaction surveys to assess the patient experience and some offer incentives to their providers based on the results. We hypothesized that providers who report being incentivized based on patient satisfaction surveys are more likely to report an impact of such surveys on their opioid prescribing practices. METHODS: We developed a 23-item survey instrument to assess the self-perceived impact of patient satisfaction surveys on opioid prescribing practices in primary care and the potential impact of institutional incentives. The survey was emailed to all 1404 members of the Colorado Academy of Family Physicians. RESULTS: The response rate to the online survey was 10.4% (n = 146). Clinical indications for which responders prescribe opioids included acute pain (93%), cancer pain (85%), and chronic nonmalignant pain (72%). Among physicians using patient satisfaction surveys, incentivized physicians reported at least a slight impact on opioid prescribing 3 times more often than physicians who were not incentivized (36% vs 12%, P = .004). CONCLUSIONS: Efforts to improve patient satisfaction may have potentially untoward effects on providers' opioid prescribing behaviors. Our results suggest a need to further study the impact of provider incentive plans that are based on patient satisfaction scores.

Genome-wide association meta-analysis of age at first cannabis use.

BACKGROUND AND AIMS: Cannabis is one of the most commonly used substances among adolescents and young adults. Earlier age at cannabis initiation is linked to adverse life outcomes, including multi-substance use and dependence. This study estimated the heritability of age at first cannabis use and identified associations with genetic variants. METHODS: A twin-based heritability analysis using 8055 twins from three cohorts was performed. We then carried out a genome-wide association meta-analysis of age at first cannabis use in a discovery sample of 24 953 individuals from nine European, North American and Australian cohorts, and a replication sample of 3735 individuals. RESULTS: The twin-based heritability for age at first cannabis use was 38% [95% confidence interval (CI) = 19-60%]. Shared and unique environmental factors explained 39% (95% CI = 20-56%) and 22% (95% CI = 16-29%). The genome-wide association meta-analysis identified five single nucleotide polymorphisms (SNPs) on chromosome 16 within the calcium-transporting ATPase gene (ATP2C2) at P < 5E-08. All five SNPs are in high linkage disequilibrium (LD) (r2  > 0.8), with the strongest association at the intronic variant rs1574587 (P = 4.09E-09). Gene-based tests of association identified the ATP2C2 gene on 16q24.1 (P = 1.33e-06). Although the five SNPs and ATP2C2 did not replicate, ATP2C2 has been associated with cocaine dependence in a previous study. ATP2B2, which is a member of the same calcium signalling pathway, has been associated previously with opioid dependence. SNP-based heritability for age at first cannabis use was non-significant. CONCLUSION: Age at cannabis initiation appears to be moderately heritable in western countries, and individual differences in onset can be explained by separate but correlated genetic liabilities. The significant association between age of initiation and ATP2C2 is consistent with the role of calcium signalling mechanisms in substance use disorders.

Marijuana Use by Adolescents and Young Adults with Inflammatory Bowel Disease.

OBJECTIVE: To evaluate marijuana use by adolescents and young adults with inflammatory bowel disease (IBD). STUDY DESIGN: This descriptive cross-sectional study of patients seen between December 2015 through June 2017 at Children's Hospital Colorado for IBD enrolled patients 13-23 years of age, independent of marijuana use status. Information obtained consisted of chart review, electronic and interview self-report, and serum cannabinoid levels. Marijuana ever-users were compared with never-users for clinical characteristics and perceptions of risk with use; users provided information on routes, patterns, motivations, and perceived benefits and problems with use. RESULTS: Of 99 participants, ever-use was endorsed by 32% (32 of 99) and daily or almost daily use by 9% (9 of 99). Older age was the only characteristic related to endorsing marijuana use. Twenty-nine ever-users completed all questionnaires. After adjusting for age, users were 10.7 times more likely to perceive low risk of harm with regular use (P < .001). At least 1 medical reason for use was endorsed by 57% (17 of 30), most commonly for relief of physical pain (53%, 16 of 30) (2 did not complete all questionnaires). Problems from use were identified by 37% (11 of 30), most commonly craving/strong urge to use. Most common route of use was smoking (83%) followed by edibles (50%), dabbing (40%), and vaping (30%). CONCLUSIONS: Marijuana use by adolescents and young adults with IBD is common and perceived as beneficial. Guidelines for screening, testing, and counseling of marijuana use should be developed for patients with IBD.

Long-term opioid use after inpatient surgery - A retrospective cohort study.

BACKGROUND: Knowledge of incidence and risk factors for long-term opioid prescribing is critical for surgical patients. In this retrospective cohort study, we linked information available at the time of surgery with prescription data to ascertain characteristics associated with prolonged opioid therapy. METHODS: Patients (n = 6003) with claims in the Colorado All Payer Claims Database (APCD) were matched with 20,501 encounters in a clinical database. Rates of prescription filling were defined by at least one monthly opioid claim relative to the date of surgery. Associations of variables with claims during months 2-6 post-operatively ("long-term prescription filling") were evaluated, and significant variables were jointly modeled using binomial regression. RESULTS: Rates of patients filling opioid prescriptions preoperatively [month (M) relative to date of surgery] were 22%(-3 M), 24%(-2 M), and 27%(-1 M); after surgery, opioid fill rates were 62%(1 M), 28%(2 M), 24%(3), 24%(4 M), 23%(5 M), and 22%(6 M). The majority, 71-76%, of patients filling prescriptions in months 2-6 after surgery had also filled before surgery. In the binomial regression model, long-term opioid use was associated with prior opioid use (p < 0.0001), age ≥26 to <65 relative to age ≥ 65 (p < 0.0001), orthopedic surgery (p = 0.001), colorectal surgery (p = 0.003), multiple procedures (p < 0.0001), and worse physical status classification (p < 0.0001). CONCLUSIONS: Patients who had filled opioid prescriptions preoperatively comprised the majority of the group who filled long-term prescriptions. Surgical procedures were associated with discontinuation of previous opioid prescribing in some patients. For others, surgery marked the initiation of prolonged opioid therapy. Surgical encounters should include interventions aimed to reduce long-term opioid use.

Opioid Use and Storage Patterns by Patients after Hospital Discharge following Surgery.

INTRODUCTION: Opioid-based analgesic therapy represents a cornerstone of pain management after surgery. The recent rise in opioid sales and opioid overdoses suggests it is important to maximize the safety of opioid prescribing after surgery. Given that patients may live with other family members in the home, safe storage and appropriate disposal of excess opioids after hospital discharge are necessary to prevent unintended secondary exposures. Identifying characteristics of patients who are likely to be prescribed excess opioids after surgery may enable more targeted prescription practices and safety interventions. Our study aimed to elucidate patient-reported opioid use patterns and modes of home storage of opioids among patients discharged home after Cesarean section (C-section) and thoracic surgery. Specifically, we sought to identify characteristics of patients who reported using about half or more versus less of the opioids prescribed to them for use after hospital discharge. METHODS: For this cohort study, we developed a survey on quality of analgesia following hospital discharge, amounts of opioids taken relative to the amount prescribed, reasons for not taking all prescribed medications, and storage and disposal methods for leftover opioids. Adult patients, who had C-section or thoracic surgery at a tertiary academic medical center, were given a web-based self-administered survey after discharge. Descriptive statistics (means and standard deviations, proportions) were used to describe the study sample and survey results. Comparisons between patients who reported taking about half or more versus less of the opioids prescribed to them for use after hospital discharge were made using unpaired t-tests, Mann-Whitney tests, and Chi-square tests as appropriate. RESULTS: The majority (53%) of respondents after C-section (N = 30) reported taking either no or very few (less than 5) prescribed opioid pills; 83% reported taking half or less; and 17% of women, reported taking all or nearly all (5 or fewer pills left over) of their opioid prescription. In a cohort of patients after thoracic surgery (n = 31) 45% reported taking either no or very few (5 or less) prescribed opioid pills; 71% reported taking half or less; and 29% of patients reported taking all or nearly all (5 or fewer pills left over) of their opioid prescription. In both cohorts, use of opioids while hospitalized was higher in the group reporting using about half or more of prescribed opioids after discharge. Leftover opioids were stored in an unlocked location in 77% and 73% of cases following C-section and thoracic surgery, respectively. CONCLUSION: Our findings from surveys in two distinct patient populations at a single academic medical center suggest that current opioid prescribing practices for pain management at hospital discharge following Cesarean section and thoracic surgery may not account for individual patients' analgesic requirements. Excess opioid pills are commonly stored in unsecured locations and represent a potential source for non-medical opioid use and associated morbidity and mortality in patients and their families. Research to develop goal-directed and patient-centered post-discharge opioid prescription practices and encourage opioid safety practices after surgery is needed.

Distinct loci in the CHRNA5/CHRNA3/CHRNB4 gene cluster are associated with onset of regular smoking.

Neuronal nicotinic acetylcholine receptor (nAChR) genes (CHRNA5/CHRNA3/CHRNB4) have been reproducibly associated with nicotine dependence, smoking behaviors, and lung cancer risk. Of the few reports that have focused on early smoking behaviors, association results have been mixed. This meta-analysis examines early smoking phenotypes and SNPs in the gene cluster to determine: (1) whether the most robust association signal in this region (rs16969968) for other smoking behaviors is also associated with early behaviors, and/or (2) if additional statistically independent signals are important in early smoking. We focused on two phenotypes: age of tobacco initiation (AOI) and age of first regular tobacco use (AOS). This study included 56,034 subjects (41 groups) spanning nine countries and evaluated five SNPs including rs1948, rs16969968, rs578776, rs588765, and rs684513. Each dataset was analyzed using a centrally generated script. Meta-analyses were conducted from summary statistics. AOS yielded significant associations with SNPs rs578776 (beta = 0.02, P = 0.004), rs1948 (beta = 0.023, P = 0.018), and rs684513 (beta = 0.032, P = 0.017), indicating protective effects. There were no significant associations for the AOI phenotype. Importantly, rs16969968, the most replicated signal in this region for nicotine dependence, cigarettes per day, and cotinine levels, was not associated with AOI (P = 0.59) or AOS (P = 0.92). These results provide important insight into the complexity of smoking behavior phenotypes, and suggest that association signals in the CHRNA5/A3/B4 gene cluster affecting early smoking behaviors may be different from those affecting the mature nicotine dependence phenotype.

Prospective effects of adolescent indicators of behavioral disinhibition on DSM-IV alcohol, tobacco, and illicit drug dependence in young adulthood.

OBJECTIVE: To identify robust predictors of drug dependence. METHODS: This longitudinal study included 2361 male and female twins from an ongoing longitudinal study at the Center for Antisocial Drug Dependence (CADD) at the University of Colorado Boulder and Denver campuses. Twins were recruited for the CADD project while they were between the ages of 12 and 18. Participants in the current study were on average approximately 15years of age during the first wave of assessment and approximately 20years of age at the second wave of assessment. The average time between assessments was five years. A structured interview was administered at each assessment to determine patterns of substance use and Diagnostic and Statistical Manual of Mental Disorders (DSM-IV; Fourth Edition) attention deficit hyperactivity disorder (ADHD), conduct disorder (CD), and drug dependence symptoms. Cloninger's Tridimensional Personality Questionnaire was also used to assess novelty seeking tendencies (NS). At the second wave of assessment, DSM-IV dependence symptoms were reassessed using the same interview. Path analyses were used to examine direct and indirect mechanisms linking psychopathology and drug outcomes. RESULTS: Adolescent substance use, CD, and NS predicted young adult substance dependence, whereas the predictive effects of ADHD were few and inconsistent. Furthermore, CD and NS effects were partially mediated by adolescent substance use. CONCLUSIONS: Adolescent conduct problems, novelty seeking, and drug use are important indices of future drug problems. The strongest predictor was novelty seeking.

Subjective effects for alcohol, tobacco, and marijuana association with cross-drug outcomes.

METHODS: The cross-drug relationship of subjective experiences between alcohol, tobacco, and marijuana and problem drug use behaviors were examined. Data were drawn from 3853 individuals between the ages of 11 and 30 years of age participating in the Colorado Center on Antisocial Drug Dependence [CADD]. Subjective experiences were assessed using a 13-item questionnaire that included positive and negative responses for alcohol, tobacco, and marijuana. Lifetime abuse and dependence on these three drugs was assessed using the Composite International Diagnostic Interview, Substance Abuse Module [CIDI-SAM]. RESULTS: Positive and negative subjective experience scales were similar for alcohol, tobacco, and marijuana, although the hierarchical ordering of items differed by drug. Subjective experience scales for each of the three drugs examined correlated significantly, with the strongest relationship being for alcohol and marijuana experiences. Significant associations were identified between how a person experienced a drug and abuse and dependence status for the same or different drug. CONCLUSION: Cross-drug relationships provide evidence for a common liability or sensitivity towards responding in a similar manner to drugs of abuse within and across different pharmacological classes.

Genetic etiology of the common liability to drug dependence: evidence of common and specific mechanisms for DSM-IV dependence symptoms.

BACKGROUND: We investigated the etiological nature of comorbid alcohol, tobacco, and cannabis DSM-IV dependence symptoms in late adolescence and young adulthood while accounting for gender differences in the magnitude of genetic and environmental influences. METHODS: Univariate and multivariate twin modeling was used to determine the heritability of each substance and the etiology of multiple drug problems in a sample of 2484 registrants of the Center for Antisocial Drug Dependence who provided data at the second wave of an ongoing longitudinal study. We report on mean and prevalence levels of whole-life DSM-IV dependence symptoms that were assessed with the Composite International Diagnostic Interview-Substance Abuse Module. Biometrical analyses were limited to age-adjusted DSM-IV dependence symptom counts from a subset of twins that reported using alcohol, tobacco, or cannabis in their lifetime. RESULTS: Male and female alcohol, tobacco, and cannabis DSM-IV symptoms are indicators of a heritable unidimensional latent continuous trait. Additive genetic factors explain more than 60% of the common liability to drug dependence. A larger proportion of the variation in each substance is attributable to substance-specific genetic and environmental factors. CONCLUSIONS: These data suggest that both common and substance-specific genetic and environmental factors contribute to individual differences in the levels of DSM-IV alcohol, tobacco, and cannabis dependence symptoms.

Common and drug-specific genetic influences on subjective effects to alcohol, tobacco and marijuana use.

AIM: To examine variation in positive and negative subjective effects to alcohol, tobacco and marijuana and covariation between these three drugs and each effect. DESIGN: Retrospective self-reports of subjective effects were collected to estimate the genetic and environmental influences and the extent of their specificity across three drugs. PARTICIPANTS: Data were drawn from 1299 adolescent and young adult same- and opposite sex twin- and sibling-pairs participating in the Colorado Center for Antisocial Drug Dependence (CADD). SETTING: A large, collaborative, longitudinal study of substance use and antisocial behavior in community and clinical adolescents. MEASUREMENT: Subjective effects were assessed using a 13-item questionnaire that included positive and negative responses to alcohol, tobacco and marijuana. FINDINGS: Heritable influences contributed moderately (additive genetic effects 16-56%) to positive and negative subjective effects to all three drugs and did not differ for males and females. Genetic and environmental contributions to positive and negative subjective effects are largely non-overlapping for tobacco and marijuana. Multivariate genetic modeling indicated that subjective effects to alcohol, tobacco and marijuana share a common, heritable etiology and that drug-specific genetic influences were an important contributor to individual differences in drug response. CONCLUSIONS: Results from our genetic analyses suggest that subjective effects to these commonly used and misused drugs are heritable and that the genetic and environmental influences on effects to one drug also influence subjective effects to other drugs.

Dizziness and the genetic influences on subjective experiences to initial cigarette use.

AIM: To examine individual differences in positive and negative subjective experiences to initial cigarette use. DESIGN: Retrospective self-reports of initial subjective experiences were examined to estimate the genetic and environmental influences and the extent of their covariation across different effects. PARTICIPANTS: Data was drawn from 2482 young adult same-and opposite sex twins- and siblings participating in the National Longitudinal Study of Adolescent Health. MEASUREMENT: Subjective experiences were retrospectively collected using the Early Smoking Experience (ESE) questionnaire. FINDINGS: Positive experiences evidenced moderate heritable contributions (40%, 95% CI: 0.22 to 0.56), as did an overall hedonic measure (34%, 95% CI: 0.22 to 0.46) and dizziness (34%, 95% CI: 0.15 to 0.52). Negative experiences evidenced small heritable contributions (13%, 95% CI: 0.00 to 0.36). Individual specific environmental influences were strong and accounted for the remaining proportion of observed variation in these experiences. Multivariate genetic modeling identified a moderately heritable underlying factor (37%, 95% CI: 0.22 to 0.52) that influenced the covariation of diverse subjective experiences and loaded most heavily on dizziness. Positive experiences also evidence residual genetic influences that were uncorrelated with other subjective experiences. CONCLUSIONS: How a person experiences their initial few cigarettes is due to both heritable contributions and environmental experiences unique to the person. The covariation of diverse subjective experiences appears to be due to a heritable latent sensitivity to the chemicals contained in an average cigarette and is best indexed by dizziness.

Subjective effects to marijuana associated with marijuana use in community and clinical subjects.

INTRODUCTION: Marijuana is the most commonly used illicit drug among adolescents. Marijuana use induces both psychological and physiological responses, which can be interpreted by an individual in a variety of ways (i.e. subjective effects). We have examined subjective effects in adolescent, young adult community, and clinical populations to determine how patterns of use may be predicted by an individual's subjective experiences with the drug. METHOD: Participants were community and clinical sample subjects drawn from the Colorado Center of Antisocial Drug Dependence (CADD) and a sample of adjudicated youth from the Denver metropolitan area (aged 11-30). They were evaluated with the Composite International Diagnostic Interview-Substance Abuse Module (CIDI-SAM) and the Lyons battery for subjective effects. Scales for subjective effects were created using Mokken scale analysis. Multivariate linear and logistic regression was used to examine associations between the subjective scales and marijuana outcomes. RESULTS: Mokken scaling revealed two subjective effects scales, positive and negative. Both scales were significantly positively associated with marijuana abuse or dependence in both the community and clinical sample and regular use in the community sample. The negative scale was negatively associated with past six-month use in the community sample (p<0.05) and clinical sample, after controlling for age and gender effects. CONCLUSIONS: These findings suggest that diverse subjective experiences with marijuana can be ordered hierarchically and that the resulting short scales can be used in either clinical or community settings. Further, they suggest that the potential for marijuana use problems is related to the type of subjective experience from marijuana exposure.

The CHRNA5/A3/B4 gene cluster variability as an important determinant of early alcohol and tobacco initiation in young adults.

BACKGROUND: One potential site of convergence of the nicotine and alcohol actions is the family of the neuronal nicotinic acetylcholine receptors. Our study examines the genetic association between variations in the genomic region containing the CHRNA5, A3, and B4 gene cluster (A5A3B4) and several phenotypes of alcohol and tobacco use in an ethnically diverse young adult sample. Significant results were then replicated in a separate adult population-representative sample. METHODS: In a selected sample, nine single nucleotide polymorphisms (SNPs) were tested for association with various nicotine and alcohol phenotypes, including age of initiation and measures of frequency, quantity, and subjective responses to the substances. Analysis was conducted with the statistical genetics program WHAP in the full sample (1075 subjects) including ethnicities as covariates and within each ethnic group sub-sample. Replication of the significant results in a separate population-based sample was carried out with the PBAT statistical genetics program. RESULTS: Two linked SNPs (rs8023462 and rs1948) located in a conserved region of the A5A3B4 gene cluster significantly predicted early age of initiation for tobacco with a hazard ratio (HR) of 1.35 (95% confidence interval [CI]1.08-1.70) for the CC genotype of rs8023462 and a HR of 1.29 (95% CI 1.01-1.63) for the TT genotype of rs1948 [corrected]. These findings were then replicated in a separate population-representative sample, showing rs1948 and rs8023462 to be associated with age of initiation for both tobacco and alcohol use (p < .01 and p < .001). CONCLUSIONS: Variations in A5A3B4 genes might influence behaviors that promote early age of experimentation with drugs.

The neuronal nicotinic receptor subunit genes (CHRNA6 and CHRNB3) are associated with subjective responses to tobacco.

Neuronal nicotinic acetylcholine receptors have been implicated in various measures of nicotine dependence. In this paper, we present findings from an exploratory study of single nucleotide polymorphisms (SNPs) in the CHRNB3 and CHRNA6 genes with tobacco and alcohol phenotypes, including frequency of use and three subjective response factors occurring shortly after initiation of use. Subjects were 1056 ethnically diverse adolescents ascertained from clinical and community settings. The most significant associations were found between two CHRNB3 SNPs (rs4950 and rs13280604) and the three subjective response factors to initial tobacco use. These findings were replicated in a separate community sample of 1524 families participating in the National Longitudinal Study of Adolescent Health. Both CHRNB3 SNPs were found to be associated with similar measures of subjective response to tobacco. These results indicate that early subjective response to nicotine may be a valuable endophenotype for genetic studies aimed at uncovering genes contributing to nicotine use and addiction.