Psychopharmacology of Tobacco and Alcohol Comorbidity: a Review of Current Evidence

Tobacco smoking is associated with antipsychotic medication, physical aggressiveness, and alcohol use disorder in schizophrenia: results from the FACE-SZ national cohort

Tobacco smoking is common in schizophrenia and is one of the main causes of premature mortality in this disorder. Little is known about clinical correlates and treatments associated with tobacco smoking in patients with schizophrenia. Still, a better characterization of these patients is necessary, in a personalized care approach. Aggressiveness and childhood trauma have been associated with tobacco smoking in general population, but this association has never been explored in schizophrenia. Our study examines the clinical and therapeutic characteristics of tobacco smoking in schizophrenia. 474 stabilized patients (mean age = 32.2; 75.7% male gender; smokers n = 207, 54.6%) were consecutively included in the network of the FondaMental Expert centers for Schizophrenia and assessed with valid scales. Current tobacco status was self-declared. Aggressiveness was self-reported with Buss-Perry Aggressiveness Questionnaire and Childhood Trauma with Childhood Trauma Questionnaire. Ongoing treatment was reported. In univariate analysis, tobacco smoking was associated with lower education level (p < 0.01), positive syndrome (p < 0.01), higher physical aggressiveness (p < 0.001), alcohol dependence (p < 0.001), and First Generation Antipsychotics (FGAs) use (p = 0.018). In a multivariate model, tobacco smoking remained associated with physical aggressiveness (p < 0.05), current alcohol dependence (p < 0.01) and FGA use (p < 0.05). No association was observed with childhood trauma history, mood disorder, suicidal behavior, psychotic symptom, global functioning or medication adherence. Patients with tobacco use present clinical and therapeutic specificities, questioning the neurobiological links between tobacco and schizophrenia. They could represent a specific phenotype, with specific clinical and therapeutic specificities that may involve interactions between cholinergic-nicotinic system and dopaminergic system. Further longitudinal studies are needed to confirm the potential efficacy of second generation antipsychotics (SGAs) on tobacco use in schizophrenia and to develop effective strategies for tobacco cessation in this population.

Alcohol use disorder and associated factors among individuals living with HIV in Hawassa City, Ethiopia: a facility based cross- sectional study

Background

Individuals living with HIV/AIDS with co-occurring harmful alcohol use may require specialized intervention or even multi-disciplinary team follow-up and management. This study was aimed to assess alcohol use disorder and associated factors among people living with HIV/AIDS in Hawassa city, Ethiopia, 2019.

Methods

A facility based cross-sectional study was conducted among 195 people living with HIV/AIDS who had follow-up visit at Hawassa University Comprehensive Specialized hospital. A systematic sampling technique was used to recruit the study participants. Alcohol used disorders identification test (AUDIT) was used to measure alcohol consumption, drinking behaviors, and alcohol-related problems. The binary logistic regression model was used to see the association between alcohol use disorder (AUD) and the independent variables. The strength of association was measured by odds ratios with 95% confidence intervals. Statistical significance declared at P < 0.05.

Results

The mean age of the study participants was 29.88 (±SD = 10.89) years. The magnitude of alcohol use disorder among people living with HIV/AIDS was 31.8%. Being male [AOR = 2.43, (95% CI: 1.76, 5.76)], having poor social support [AOR = 1.34, (95% CI: 1.12, 6.73)], being medication non-adherent [AOR = 1.78, (95% CI: 1.33, 6.79)], current khat chewing [AOR = 1.67, (95% CI: 1.16, 5.45)] and current cigarette smoking [AOR = 3.76, (95% CI: 2.16, 7.54)] had statistically significant association with alcohol use disorder.

Conclusion

In the current study, magnitude of alcohol use disorder among people living with HIV was high and, calls for integrating services provided to HIV patients in HIV care and treatment clinic which enhances timely detection and management of AUD cases. This also alerts the stakeholders in HIV prevention and control programs to invest a greater efforts to retain patients in addiction treatment and rehabilitation centers. Lastly, appropriate screening and health education on consequences of alcohol use disorder is warranted.

Risk factors associated with physical and mental distress in people who report a COPD diagnosis: latent class analysis of 2016 behavioral risk factor surveillance system data

Introduction

Challenges associated with COPD increase patients’ risk of physical immobility and emotional distress, perpetuating a cycle of symptomatic living that hinders patients’ self-management and adherence to a treatment regimen. There is limited evidence available on how discrete behavioral and health risk factors contribute to the physical and mental distress experienced by people living with COPD.

Purpose

This secondary data analysis of 2016 Behavioral Risk Factor Surveillance System (BRFSS) sought to identify subgroups of people with COPD who were at the highest risk for physical and mental distress.

Methods

We selected 16 relevant risk indicators in four health-related domains – 1) health risk behaviors, 2) lack of preventive vaccinations, 3) limited health care access, and 4) comorbidities – as predictors of physical and mental health-related quality of life (HRQoL) in the COPD population. Latent class modeling (LCM) was applied to understand how various health-related indicators in these four health domains influenced reports of physical and/or mental distress.

Results

The majority of BRFSS respondents who reported a COPD diagnosis experienced physical (53.76%) and/or mental (58.23%) distress in the past 14 days. Frequent physical and mental distress were more common in females with COPD in the 45–64 years age group, who were also identified as white and in the lower socioeconomic group. Respondents with intermediate- to high-risk behaviors, intermediate to multiple comorbidities, limited access to health care, and intermediate to low use of preventive vaccinations were more likely to report frequent physical distress compared to the low-risk respondents. Similarly, respondents with high-risk behaviors, intermediate to multiple comorbidities, and low use of preventive vaccinations were more likely to report frequent mental distress than the low-risk group.

Discussion

This analysis of updated 2016 BRFSS data identified high-risk Americans with COPD who could benefit from disease management and secondary/tertiary health promotion interventions that may improve HRQoL. Future research should address noted disparities in risk factors, particularly among low socioeconomic populations living with COPD.

Frequency-Specific Abnormalities Of Functional Homotopy In Alcohol Dependence: A Resting-State Functional Magnetic Resonance Imaging Study

PURPOSE

Alcohol dependence (AD) is a relapsing mental disorder, typically occurring with concurrent tobacco misuse. Studies have reported disruption of the structural connectivity between hemispheres in the brain of individuals with AD. However, alterations in interhemispheric interactions and the specificity of frequency bands in individuals with AD remain unknown. Voxel-mirrored homotopic connectivity (VMHC) allows examination of functional interactions between mirrored interhemispheric voxels. Here, we use VMHC to investigate homotopic connectivity in AD and alcohol and nicotine co-dependence (AND) subjects.

PATIENTS AND METHODS

VMHC and seed-based functional connectivity (FC) in 24 AD, 30 AND, and 35 sex-, age-, and education-matched healthy control (HC) subjects were calculated for different frequency bands (slow-5, slow-4, and typical bands).

RESULTS

Individuals with AD demonstrated significantly reduced VMHC in bilateral cerebellum posterior lobe (CPL) and increased VMHC in bilateral middle frontal gyrus (MFG) compared to that in HCs in the typical and slow-4 bands; higher VMHC in the MFG was positively correlated with the dependence-severity score. In all bands of the VMHC analysis, no significant differences were found between the AND and other groups. Subsequent seed-based FC analysis demonstrated all regions with abnormal VMHC exhibited altered FC with its counterpart in the contralateral hemisphere in the typical and slow-4 frequency bands. The FC value between bilateral CPL within AD subjects negatively correlated with alcohol intake.

CONCLUSION

Our findings provide further evidence of the role of disruptions within the brain circuitry supporting cognitive control in the development of AD. Alterations in neural activities in the CPL and MFG might be a biomarker of dependence severity in AD patients as assessed using clinical questionnaire and features. Because of the frequency specificity in VMHC, we must consider frequency effects in future AD functional magnetic resonance imaging studies.

Cigarette Use Among Individuals with Alcohol Use Disorders in the United States, 2002 to 2016: Trends Overall and by Race/Ethnicity

BACKGROUND

Individuals with alcohol use disorders (AUDs) who smoke cigarettes experience greater health risks than those using either substance alone. Further, disparities exist in AUDs and smoking by race/ethnicity. Although smoking has declined in the general population, it is not known whether the smoking prevalence has changed over time for individuals with AUDs. The current study used representative U.S. data to estimate the prevalence of current cigarette use from 2002 to 2016 by AUD status and severity overall and by race/ethnicity.

METHODS

Data were drawn from the National Survey on Drug Use and Health, an annual cross-sectional study of U.S. individuals, from 2002 to 2016 (total analytic sample n = 837,326). Cigarette smoking prevalence was calculated annually among those with and without past-year AUD and by AUD severity level (mild, moderate, severe AUD). Time trends in smoking prevalence by AUD status and severity were tested using logistic regression for the overall sample and significant interactions were subsequently stratified by race/ethnicity (non-Hispanic [NH] White, NH Black, Hispanic, NH Other).

RESULTS

Cigarette use was persistently over twice as common among those with AUDs compared to without AUDs (2016: 37.84% vs. 16.29%). Cigarette use was also more common among those at each level of AUD severity criteria (2016: mild AUD 34.59%; moderate AUD 35.35%; severe AUD 52.23%). Approximately half of NH Black respondents with AUDs, and three-quarters of NH Black respondents with severe AUDs, reported smoking in 2016. The prevalence of smoking decreased significantly over time among respondents with and without AUDs; however, there were differences by race. There was no decline in smoking prevalence among NH Black respondents with AUDs over time in contrast to a significant decrease for every other racial/ethnic group with and without AUDs.

CONCLUSIONS

Individuals with AUDs may need additional resources and interventions to quit smoking, especially NH Black individuals.

Zebrafish as an alternative method for determining the embryo toxicity of plant products: a systematic review

The toxicological assessment of plant products and pharmaceutical chemicals is a necessary requirement to ensure that all compounds are safe to be exposed to humans. Many countries are trying to reduce the use of animals; thus, alternative techniques, such as ex vivo tests, in vitro assays, and ex uteri embryos, are used. Toxicological assays using zebrafish embryos are an advantageous technique because they are transparent, have rapid embryonic development, and do not require invasive techniques. This paper comprehensively reviews how toxicity testing with plant products is conducted in zebrafish embryos. The search terms zebra fish, Danio rerio, zebrafish, zebra danio, Brachydanio rerio, zebrafish, and embryos were used to search for English-language articles in PUBMED, SCOPUS, and WEB OF SCIENCE. Twelve articles on plant product toxicity studies using zebrafish were selected for reading and analysis. After analyzing the articles and comparing with results in mammals, it was possible to prove the similarity among the results and thus corroborate the further development of zebrafish as a valid tool in toxicity tests.

Informing population-specific smoking policy development for college campuses: An observational study

INTRODUCTION

In Canada, young adults have the highest smoking rates among all other population groups and specifically college students are at a higher risk. To implement effective policies that can prevent smoking and increase cessation, a population-specific approach is recommended.

METHODS

Smoking and non-smoking young adults enrolled in a college program were recruited. Participants who did not smoke were asked to complete questionnaires about their demographics, college experience and the college environment. Additionally, they completed The Perceived Stress Scale and The Center for Epidemiologic Studies - Depression Scale. Students who were current smokers completed the same questionnaires with the addition of one questionnaire about their smoking behaviors. Percentages, means and standard deviations were used to describe the variables of interest and a chi-squared analysis was performed, when possible, to test the difference in response frequency between smoking and non-smoking participants.

RESULTS

Differences were observed between smoking (n=65) and non-smoking students (n=214). Specifically, smokers were more likely to have a family member that smoked and to participate in binge drinking. Both groups indicated that they are unaware of campus smoking regulations; however smokers were more opposed to implementing smoke-free policies.

CONCLUSIONS

College students are unaware of campus smoking regulations. The descriptive information and differences observed between smoking and non-smoking students in this study should be taken into consideration when developing future smoking regulations/policies on college campuses.

Tobacco and alcohol use disorders: Evaluating multimorbidity

There is growing interest in applying the multimorbidity model for mental health disorders - i.e. the interactive effects of co-occurring diagnoses. Alcohol use disorder (AUD) and tobacco use disorder (TUD) often occur together, but distinctive correlates of their co-occurrence have not been studied. Veterans treated by the Veterans Health Administration (VHA) nationally in FY 2012 with diagnoses of both AUD and TUD were compared to those with only AUD or only TUD on socio-environmental factors, medical and psychiatric diagnoses, and service use. Multimorbid effects were defined as those in which patients with both AUD and TUD had more serious problems greater likelihood of specific co-occurring conditions than those with either AUD alone or TUD alone. Veterans with concurrent AUD and TUD (N=153,397), as compared to those with AUD only (N=191,900) or with TUD only (N=643,377), had significantly higher rates of homelessness [odd ratios (ORs)=1.24, 1.68], hepatic disease (ORs=1.11, 2.18), substance use disorders (ORs=1.42, 3.14), receipt of a VA disability pension (ORs=1.26, 1.30) and use of substance and mental health outpatient services (ORs=1.04, 1.12). Veterans with AUD and TUD appear to have more severe problems in some, but not all, socio-environmental, medical, psychiatric, and service use domains than veterans with either of these diagnoses alone. The combination of AUD and TUD yield generally more adverse effects in diverse areas and thus reflect an emergent phenomenon that may a require a distinctive treatment approach.

Effects of Nicotine on Alcohol Drinking in Female Mice Selectively Bred for High or Low Alcohol Preference

BACKGROUND

Studies show that repeated nicotine use associates with high alcohol consumption in humans and that nicotine exposure sometimes increases alcohol consumption in animal models. However, the relative roles of genetic predisposition to high alcohol consumption, the alcohol drinking patterns, and the timing of nicotine exposure both with respect to alcohol drinking and developmental stage remain unclear. The studies here manipulated all these variables, using mice selectively bred for differences in free-choice (FC) alcohol consumption to elucidate the role of genetics and nicotine exposure in alcohol consumption behaviors.

METHODS

In Experiments 1 and 2, we assessed the effects of repeated nicotine (0, 0.5, or 1.5 mg/kg) injections immediately before binge-like (drinking-in-the-dark; Experiment 1) or during FC alcohol access (Experiment 2) on these alcohol drinking behaviors (immediately after injections and during re-exposure to alcohol access 14 days later) in adult high- (HAP2) and low-alcohol-preferring (LAP2) female mice (co-exposure model). In Experiments 3 and 4, we assessed the effects of repeated nicotine (0, 0.5, or 1.5 mg/kg) injections 14 days prior to binge-like and FC alcohol access on these alcohol drinking behaviors in adolescent HAP2 and LAP2 female mice (Experiment 3) or adult HAP2 female mice (Experiment 4).

RESULTS

In Experiment 1, we found that repeated nicotine (0.5 and 1.5 mg/kg) and alcohol co-exposure significantly increased binge-like drinking behavior in HAP2 but not LAP2 mice during the re-exposure phase after a 14-day abstinence period. In Experiment 2, 1.5 mg/kg nicotine injections significantly reduced FC alcohol intake and preference in the third hour postinjection in HAP2 but not LAP2 mice. No significant effects of nicotine treatment on binge-like or FC alcohol drinking were observed in Experiments 3 and 4.

CONCLUSIONS

These results show that the temporal parameters of nicotine and alcohol exposure, pattern of alcohol access, and genetic predisposition for alcohol preference influence nicotine's effects on alcohol consumption. These findings in selectively bred mice suggest that humans with a genetic history of alcohol use disorders may be more vulnerable to develop nicotine and alcohol co-use disorders.

Neuregulin signaling pathway in smoking behavior

Understanding molecular processes that link comorbid traits such as addictions and mental disorders can provide novel therapeutic targets. Neuregulin signaling pathway (NSP) has previously been implicated in schizophrenia, a neurodevelopmental disorder with high comorbidity to smoking. Using a Finnish twin family sample, we have previously detected association between nicotine dependence and ERBB4 (a neuregulin receptor), and linkage for smoking initiation at the ERBB4 locus on 2q33. Further, Neuregulin3 has recently been shown to associate with nicotine withdrawal in a behavioral mouse model. In this study, we scrutinized association and linkage between 15 036 common, low frequency and rare genetic variants in 10 NSP genes and phenotypes encompassing smoking and alcohol use. Using the Finnish twin family sample (N=1998 from 740 families), we detected 66 variants (representing 23 LD blocks) significantly associated (false discovery rate P<0.05) with smoking initiation, nicotine dependence and nicotine withdrawal. We comprehensively annotated the associated variants using expression (eQTL) and methylation quantitative trait loci (meQTL) analyses in a Finnish population sample. Among the 66 variants, we identified 25 eQTLs (in NRG1 and ERBB4), 22 meQTLs (in NRG3, ERBB4 and PSENEN), a missense variant in NRG1 (rs113317778) and a splicing disruption variant in ERBB4 (rs13385826). Majority of the QTLs in blood were replicated in silico using publicly available databases, with additional QTLs observed in brain. In conclusion, our results support the involvement of NSP in smoking behavior but not in alcohol use and abuse, and disclose functional potential for 56 of the 66 associated single-nucleotide polymorphism.