A population-based twin study of the genetic and environmental relationship of major depression, regular tobacco use and nicotine dependence

Department of Psychiatry, Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Richmond, VA 23298-0126, USA.
Psychological Medicine (Impact Factor: 5.94). 02/2011; 41(2):395-405. DOI: 10.1017/S0033291710000589
Source: PubMed


Numerous epidemiological studies have reported a positive association between major depression (MD) and regular tobacco use (RU) or nicotine dependence (ND). However, few have used a genetically informative design to assess whether these traits share a common genetic and/or environmental liability.
We assessed MD, RU and ND in same-sex twins from the population-based Swedish Twin Registry. In males, we examined both cigarette use and snus (smokeless tobacco) use. We used structural equation modeling to examine the relationship between MD, RU, and ND given RU.
The results suggest modest correlations between MD and RU, and between MD and ND. In males, the liability shared between MD and RU is solely genetic for both cigarettes and snus, while MD and ND share both genetic and unique environmental influences. The continuation to ND given RU differed considerably between cigarette and snus users. In females, both MD-RU and MD-ND relationships are partially attributable to genetic and unique environmental correlations.
The relationship among MD, RU and ND is at least partially attributable to shared genetic and environmental risk factors. The genetic and environmental correlations between traits are modest. The nature of the shared liability differs by sex, and in males, by the type of tobacco product used. Differences between previous reports and results presented in the current study are suggestive of population differences in how MD and tobacco use inter-relate.

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Available from: Alexis Edwards, Nov 09, 2015
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    • "Underlying genetic factors may in part explain this difference. There is stronger evidence for genetic pleiotropy of substance use and externalizing problems than there is for substance use and internalizing psychopathology (Edwards et al. 2011; Hicks et al. 2011; Kendler et al. 2003; Stephens et al. 2012) and thus even without any causal effects of prenatal smoking, an association of maternal smoking and externalizing offspring behavior is expected as mothers pass on their risk genes to their offspring. The association of prenatal smoking with offspring externalizing problems may be further amplified by interactions between offspring Table 3 P values in the regression of the dependent phenotype (column 1) on the covariates (columns 2–6) and the predictor of interest (''maternal vs. paternal SDP''; column 11) "
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    ABSTRACT: Maternal smoking during pregnancy (SDP) is associated with increased risk of externalizing and internalizing behaviors in offspring. Two explanations (not mutually exclusive) for this association are direct causal effects of maternal SDP and the effects of genetic and environmental factors common to parents and offspring which increase smoking as well as problem behaviors. Here, we examined the associations between parental SDP and mother rated offspring externalizing and internalizing behaviors (rated by the Child Behavior Checklist/2-3) at age three in a population-based sample of Dutch twins (N = 15,228 pairs). First, as a greater effect of maternal than of paternal SDP is consistent with a causal effect of maternal SDP, we compared the effects of maternal and paternal SDP. Second, as a beneficial effect of quitting smoking before pregnancy is consistent with the causal effect, we compared the effects of SDP in mothers who quit smoking before pregnancy, and mothers who continued to smoke during pregnancy. All mothers were established smokers before their pregnancy. The results indicated a greater effect of maternal SDP, compared to paternal SDP, for externalizing, aggression, overactive and withdrawn behavior. Quitting smoking was associated with less externalizing, overactive behavior, aggression, and oppositional behavior, but had no effect on internalizing, anxious depression, or withdrawn behavior. We conclude that these results are consistent with a causal, but small, effect of smoking on externalizing problems at age 3. The results do not support a causal effect of maternal SDP on internalizing behaviors.
    Full-text · Article · Sep 2015 · Behavior Genetics
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    • "One aspect of the susceptibility to the disorder is reflected in the subjective response to alcohol, which like all drugs of abuse, has been shown to be partly heritable (van den Bree et al., 1998; Edwards et al., 2011; Heath and Martin, 1994; Heath et al., 2001; Kendler et al., 1992, 1999, 2000; Prescott and Kendler, 1995; Tsuang et al., 2001; Verweij et al., 2010). The application of genetic methods to the study of AUD thus has the potential to enhance our understanding of the mechanisms underlying key aspects of the development of AUD, for example, by helping to elucidate the role of genetic variation in both the subjective effects of alcohol and the response to the pharmacological treatment of AUD. "
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    ABSTRACT: Previous studies have found inverse associations between intelligence quotient (IQ) and cigarette smoking, but the causal pathways linking IQ with smoking status and nicotine dependence (ND) are not well understood. The aim of this study was to explore the associations between IQ and ND using a genetically informative twin design to detect whether any association is because of shared genetic or environmental factors. A population-based twin cohort with IQ measured in adolescence and ND later in life, analysed by classical twin modeling based on linear structural equations. Swedish national registry data. A total of 5040 male twins born 1951-84. IQ was measured at military conscription at a mean age of 18 years. ND was self-reported at the ages of 22-57 years using the Fagerström Test for ND scale (FTND). Both cigarette smoking and Swedish snus use were analysed. Both IQ and ND showed moderate heritability (0.58 and 0.39, respectively). The heritability of ND was similar for cigarette smoking and snus use. The phenotypic correlation between IQ and ND was weak: -0.11 (-0.16, -0.06) for total ND. Bivariate analysis revealed that this correlation was mainly because of genetic factors, but still the genetic correlation between IQ and ND from cigarette smoking was only -0.24. Nicotine dependence, as measured by the Fagerström Test for Nicotine Dependence, shows moderate heritability in both smokers and snus users but is only weakly associated with intelligence quotient; common genetic factors underlying nicotine dependence and intelligence quotient probably account for little of the observed association between smoking and intelligence quotient.
    No preview · Article · Feb 2011 · Addiction
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