Current Drug Abuse Reviews - Volume 9, Issue 1, 2016

Background: Laterality of brain activation is reported for tests of risk factors of addiction— impulsivity and craving—but authors rarely address the potential significance of those asymmetries. Objective: The purpose of this study is to demonstrate this laterality and discuss its relevance to cognitive and neurophysiological asymmetries associated with drug abuse vulnerability in order to provide new insights for future research in drug abuse. Method: From published reports, brain areas of activation for two tests of response inhibition or craving for drugs of abuse were compiled from fMRI activation peaks and were tabulated for eight sections (octants) in each hemisphere. Percent asymmetries were calculated (R-L/R+L) across studies for each area. Results: For impulsivity, most activation peaks favored the right hemisphere. Overall, the percent difference was 32% (2 = 16.026; p < 0.0001) with the greater asymmetry for anterior peaks (46.8%; 2 = 17.329; p < 0.0001). The asymmetries for cue-induced craving were opposite, favoring the left hemisphere by 6.7% (2 = 4.028; p < 0.05). The consistency of left asymmetry was found for almost all drugs. For nicotine, studies where subjects were not allowed to smoke (deprived) prior to measurement had the same left hemisphere activation but those who smoked (satiated) before the fMRI measure showed right asymmetry. Conclusion: Brain activation studies demonstrate different left/right hemispheric contributions for impulsivity versus craving—factors related to addiction. Failure to take laterality into consideration is a missed opportunity in designing studies and gaining insight into the etiology of drug abuse and pathways for treatment.

Background: Alcohol abuse is a common problem that is socially, psychologically and economically devastating to health of individuals. Objectives: the purpose of this study was to examine the interrelationship between alcohol relapse, self efficacy, perceived social support, and perceived stress among individual diagnosed with alcohol dependence. Methods: A cross-sectional descriptive correlational design was utilized to collect data using selfadministered questionnaire from a purposeful sample of 111 Jordanians diagnosed with alcohol dependence. Data collected in regards to self efficacy, perceived social support, and perceived stress. Results: patients reported moderate to severe psychological distress, moderate level of self-efficacy, and moderate perception of social support. The analysis also showed that self-efficacy and perceived social support from other and from friends have negative and not significant correlation with relapse. Also age had significant and positive correlation with relapse. Marital status and duration of alcohol dependence were significant predictors of relapse. Conclusion: Stress and socio-demographic characteristic are significant factors to be considered while planning for alcohol relapse prevention.

The current review provides an overview of socioepidemiological research in Germany about the prevalence of addictive behaviours (smoking, binge and hazardous drinking, consumption of cannabis and other illegal drugs, the non-medical use of prescription drugs and problematic gambling) among adolescents (11-17 years) and young adults (18-25 years), also differentiating between different socioeconomic status (SES) indicators (attended school type, family affluence, parental occupational status, parental SES, employment status) and migration background. The authors evaluated data from ten national surveys and one regional survey conducted between 2002 and 2012, which included different samples. The trends over this time frame reveal that the proportion of adolescents who smoke tobacco, show problematic patterns of alcohol consumption, use cannabis or other illegal drugs has generally declined over the investigated time span in Germany. The results nevertheless suggest that some strong associations still exist between social inequalities and the prevalence of substance use. The detailed results are summarised in twelve tables. The main results are as follows: 1) Low SES (school type, employment status) was consistently associated with more cigarette smoking, and, where such data was available, this pattern was observed in both males and females. 2) With regard to family affluence, two surveys show that boys with low and middle FAS are significantly less likely to have binge drinking experience compared to boys with high FAS. There were no significant associations between problematic alcohol use and parental SES, and not all results of the surveys show that binge drinking is more prevalent among HS-students. Employment status was associated with gender differences; problematic patterns of alcohol consumption were significantly more prevalent among young unemployed males compared to GY-students (secondary high school/grammar school) of the same age. The opposite was true for females. Another consistent finding was that among adolescents and young adults with a Turkish/Asian migration background, a problematic use of alcohol was significantly less common compared to adolescents and young adults of the same age without a migration background. 3) In terms of the consumption of cannabis, the unemployed and students with low educational level (`Hauptschule´) emerge as high-risk groups. 4) The results concerning problematic gambling significantly overlap with and reflect the findings of international research: being male, of low educational attainment, unemployed, receiving social welfare, and having a migration background significantly increased the risk of problematic gambling habits. 5) The highest lifetime prevalence rates for the consumption of illegal drugs (other than cannabis) were observed among students with low educational level. It should be noted that other SES indicators, in addition to school type, have not been examined to date. The review concludes by outlining gaps and future research areas, as well as presenting several implications for prevention initiatives.

Background: While chronic pain has been said to impact patient’s response to methadone maintenance treatment for opioid dependence, the reported findings are inconsistent. These discrepancies may be a direct result of variations in the measurement of chronic pain or definitions of response to methadone treatment. The goal of this study is to evaluate the association between pain and substance use behaviour to determine the real impact of comorbid pain in the methadone population. We also aim to examine sources of variation across the literature with a specific focus on the measurement of pain. Methods/Design: We performed a systematic review using an electronic search strategy across CINAHL, MEDLINE, Web of Science, PsychINFO, EMBASE, and the Cochrane Library including Cochrane Reviews and the Cochrane Central Register of Controlled Trials databases. Title, abstract, as well as full text screening and extraction were performed in duplicate. Studies evaluating the association between chronic pain and methadone maintenance treatment response were eligible for inclusion in this review. Using a sample of 297 methadone patients from the Genetics of Opioid Addiction (GENOA) research collaborative, we assessed the reliability of patient self-reported pain and the validated Brief Pain Inventory (BPI) assessment tool. Results: After screening 826 articles we identified five studies eligible for full text extraction, of which three showed a significant relationship between the presence of pain and the increase in substance abuse among patients on methadone for the treatment of opioid dependence. Studies varied largely in the definitions and measurement of both pain and response to treatment. Results from our validation of pain measurement in the GENOA sample (n=297) showed the use of a simple self-reported pain question is highly correlated to the use of the BPI. Simply asking patients whether they have pain showed a 44.2% sensitivity, 88.8% specificity, 84.4% PPV and 53.6% NPV to the BPI. The area under the ROC curve was 0.67 and the Pearson χ2 was 37.3; (p<0.0001). Discussion: The field of addiction medicine is at a lack of consensus as to the real effect of chronic pain on treatment response among opioid dependent patients. Whether it be the lack of a single “gold standard” measurement of response, or a lack of consistent measurement of pain, it is difficult to summarize and compare the results of these relatively small investigations. In comparison to the BPI, use of the simple self-reported pain has lower sensitivity for identifying patients with pain, suggesting the inconsistencies in these studies may result from differences in pain measurement. Future validation studies of pain measurement are required to address the predictive value of self-reported pain.

The literature on the two main models of addiction (dopamine-based positive reinforcement and stress-based negative reinforcement models) have made many important contributions to understanding this brain disorder. However, rarely has there been a comprehensive critique of the limitations of both models. This article seeks to resolve theoretical issues inherent to each model, as well as propose a more comprehensive psycho-neuro-endocrinological theory of addiction which reconciles important elements of both. We suggest that there is not only direct interaction of dopaminergic and stress systems throughout the addiction cycle, from initial use, via the abusing stage, to the endpoint of addiction, but that this interaction is present prior to initial use. A combination of genetic factors and/or experiences of adversity may result in a stress-triggered sensitisation of dopaminergic networks which is present before the onset of substance use, which cannot be explained solely in terms of dopaminergic (positive) reinforcement. Rather these processes are best explained by an allostatic model which reconciles aspects of both models of addiction and shows how dopamine/stress interactions become increasingly pathological in the addiction cycle. Our model suggests that chronic stress eventually creates baseline hypodopaminergic activity, but also prompts dopaminergic hyperactivity in cue reactivity. This is the neural marker of allostatic mechanisms observed at endpoint addiction. We propose a multi-circuit explanation of how this cumulative effect of stress increasingly impacts on dopaminergic networks of reward, affect, attention, memory and behavioural control. This revised model provides a useful frame of reference for further research and ultimately clinical practice.