Dace S. Svikis

Sex and Age Effects on the Inheritance of Alcohol Problems: A Twin Study

Male monozygotic cotwins of probands with Alcohol Abuse-Dependence (n = 85) were more likely than male same-sex dizygotic cotwins (n = 96) to report alcohol, drug, and conduct disorder problems. For women, rates of problem behavior did not differ between monozygotic (n = 44) and same-sex dizygotic (n = 43) cotwins. Opposite-sex dizygotic twin data (n = 88) revealed significant cross-sex transmission; alcohol problems were greatest among male cotwins of female probands. For men, proportion of liability variance associated with additive genetic factors was significantly greater when proband had an early (h2 = .73 +/- .18) rather than late (h2 = .30 +/- .26) age of onset. For women, heritability did not vary as a function of probands age of onset, and the pooled estimate suggested little genetic influence (h2 = .00, SE not computable). Findings suggest that genetic influences may be substantial only in the etiology of early-onset male alcoholism.

A reinforcement-based therapeutic workplace for the treatment of drug abuse: three-year abstinence outcomes.

Long-term Therapeutic Workplace effects were evaluated in heroin- and cocaine-dependent, unemployed, treatment-resistant young mothers. Participants were paid to work or to train in the Therapeutic Workplace but had to provide drug-free urine samples to gain daily access. Participants (N = 40) were randomly assigned to a Therapeutic Workplace or usual care control group. Therapeutic Workplace participants could work for 3 years. Relative to controls, Therapeutic Workplace participants increased cocaine (28% vs. 54% negative; p = .04) and opiate (37% vs. 60% negative; p = .05) abstinence on the basis of monthly urine samples collected until 3 years after intake. The Therapeutic Workplace can be an effective long-term treatment of cocaine and heroin addiction in poor and chronically unemployed young mothers.

Buprenorphine treatment of pregnant opioid-dependent women: maternal and neonatal outcomes

This open-label prospective study examined maternal and neonatal safety and efficacy outcome measures during and following prenatal buprenorphine exposure. Three opioid-dependent pregnant women received 8 or 12 mg sublingual buprenorphine tablets daily for 15-16 weeks prior to delivery. Results showed that buprenorphine in combination with comprehensive prenatal care was safe and effective in these women. Prenatal exposure to buprenorphine resulted in normal birth outcomes, a mean of 4.33 days (minimum possible=4) hospitalization, and a relatively mild neonatal abstinence syndrome comprised primarily of tremors (disturbed), hyperactive moro and shortened sleep after feeding. The infants required no pharmacological treatment. Onset of neonatal abstinence signs occurred within the first 12 h after birth, peaked by 72 h and returned to below pre-12 h levels by 120 h. It is concluded that buprenorphine has potential utility for the treatment of pregnant opioid-dependent women.

Common genetic mechanisms in alcohol, drug, and mental disorder comorbidity

Comorbid drug and mental disorders were assessed in 63 monozygotic (MZ) and 67 dizygotic (DZ) twin pairs. DSM-III alcohol dependence was heritable in males when probands had a comorbid DSM-III drug or mental disorder but not when probands had only alcohol dependence. For males, significantly higher cross-MZ than cross-DZ correlations were found between alcohol dependence in probands and certain mental and drug disorders in cotwins. In contrast, females showed higher within-twin than cross-MZ correlations and similar cross-MZ and cross-DZ correlations between alcohol dependence and all mental and drug disorders. These results suggest comorbidity between alcohol and certain drug and mental disorders in males in epidemiological surveys may be due in part to genetic influences.

Twin closeness and co-twin risk for substance use disorders: assessing the impact of the equal environment assumption

Various environmental variables are hypothesized to operate differentially within identical and fraternal twin pairs. To the extent that these factors are correlated with behavioral outcomes, such as alcohol or drug abuse, traditional twin studies of concordance may be biased. Self-ratings of within-pair emotional closeness, assessed in 169 same-sex twin pairs ascertained through alcohol and drug treatment centers, were used to determine the impact of the twin relationship on concordance for alcohol dependence (N = 130 twin pairs) and other drug abuse and/or dependence (N = 85 twin pairs). In general, identical twin pairs reported significantly closer relationships than fraternal twin pairs, and female twin pairs reported significantly closer relationships than male twin pairs. The data did not indicate an overall effect of closeness on co-twin risk for alcohol dependence. In contrast, closeness was significantly related to co-twin risk for other drug abuse and/or dependence. However, the MZ/DZ concordance difference for other drug abuse and/or dependence remained significant when the effects of within-pair closeness were controlled. Thus, the initial zygosity and sex differences in concordance for substance use disorders cannot be explained solely by differences in twin relationship due to closeness as assessed in this study.

Assessing maternal perceptions of harmful effects of drug use during pregnancy.

Abstract Research has shown that perceived risk is an important predictor of health behavior change. In turn, drug use risk education is a vital component of many health campaigns. In pregnant women, perceived risk studies have focused primarily on alcohol and tobacco use. Little is known about perceived risks associated with prenatal exposure to illicit drugs. The present study compared drug use attitude (DUA) in both treatment-seeking and non-treatment-seeking drug-using pregnant women as well as a comparison group of non-drug-using pregnant women. The results suggest that non-treatment-seekers are less knowledgeable about specific potential risks of perinatal substance use. In addition, compared to treatment seekers and non-users, non-treatment-seekers were more likely to endorse cutting down on drug use rather than quitting as a means of reducing harm to the developing child. Results ofthe present study suggest drug-using women may benefit from additional education about harmful effects of drug use.