Extra-medical stimulant dependence among recent initiates

Male-female differences in the onset of heavy drinking episode soon after first full drink in contemporary United States: From early adolescence to young adulthood

BACKGROUND

Globally, there is a male excess in the occurrence of heavy drinking once alcoholic beverages are consumed and some new evidence that this 'gender gap' might be null among underage drinkers. Here, we estimate age-specific male-female differences in heavy drinking episode (HDE) incidence across the first eight calendar-quarters after first full drink.

METHODS

Study population is non-institutionalized civilians in the United States (2006-2014). Standardized audio computer-assisted self-interviews were used to assess the date of first full drink and the date of first HDE (i.e., 5+ drinks on one occasion) among ∼33,000 12-to-21-year-old newly incident drinkers (all with 1st full drink and HDE evaluated within 24 months of drinking onset). Time-to-HDE survival analyses are used to estimate age-specific male-female ratios in the hazard of HDE onset.

RESULTS

We found that among early adolescent new drinkers (drinking onset at age 11-14), the newly incident drinking females progress to HDE more quickly than males (HR = 1.3, 95% CI = 1.1, 1.6). In contrast, male excess risk is observed when drinking starts at or after age 15 years. For underage drinkers, age-specific hazard ratios (HR) depend upon age at first full drink.

CONCLUSIONS

Based on recent survey data from the US, this study's survival analyses support early adolescent female excess in the onset of HDE. When drinking starts at or after age 15 years, a male excess becomes apparent within two years since first full drink. Future studies may probe any sex-specific mechanisms toward the rapid onset of HDE at different age groups.

Social rank and inhalant drug use: the case of lança perfume use in São Paulo, Brazil

BACKGROUND

Lanca perfume (chloroform/ether) is an inhalant used mainly by higher social class students in Brazil. In light of the social and epidemiological features of lanca use, supply, and distribution, this investigation tests hypotheses about the degree to which use of inhalant lanca might be occurring in clusters, consistent with social sharing and diffusion, and might show a direct association with social rank even within the relatively privileged social context of private schools in a large mega-city of Latin America.

METHODS

Epidemiologic self-report survey data were from a large representative sample of urban post-primary private school students in São Paulo city, Brazil, in 2008. Newly incident lanca use was studied, first with estimates of clustering from the alternating logistic regressions (ALR) and then with conditional logistic regressions to probe into the hypothesized direct social rank association.

RESULTS

ALR disclosed a clustering of newly incident lanca users within private school classrooms (pairwise odds ratio (PWOR)=2.1; 95% CI=1.3, 3.3; p=0.002) as well as clusters of recently active lanca use (PWOR=1.9; 95% CI=1.1, 3.3; p=0.02). Occurrence of lanca use within private school classrooms was directly associated with social rank (odds ratio (OR)=0.2; 95% CI=0.1, 0.8; p=0.03 in the contrast of lowest socio-economic status (SES) versus highest SES strata within classrooms). Thereafter, study of other drugs disclosed similar patterns.

CONCLUSIONS

The clustering estimates are consistent with concepts of person-to-person sharing of lanca within private school classrooms as well as other dynamic processes that might promote lanca clusters in this context. An observed direct association with social rank is not specific to lanca use. Direct SES estimates across a broad profile of drug compounds suggests causal processes over and above the more specific initially hypothesized social rank gradients in the lanca diffusion process. A novel facet of the evidence is greater occurrence of drug use among the higher social rank private school students, which should be of interest in the social science community.

Patterns of methylphenidate use and assessment of its abuse and diversion in two French administrative areas using a proxy of deviant behaviour determined from a reimbursement database: main trends from 2005 to 2008

BACKGROUND

Methylphenidate is a psychostimulant drug indicated for the treatment of attention-deficit hyperactivity disorder (ADHD). Its abuse and diversion have been previously described in specific populations, such as students; however, few studies investigating abuse and diversion among the overall population are available.

OBJECTIVES

The aim of this study was to describe patterns of methylphenidate use and to explore the magnitude of its abuse and diversion in two French administrative areas using data from a reimbursement database. A proxy of 'deviant behaviour' was used for the abuse and diversion of methylphenidate, defined using the following parameters: total number of defined daily doses (DDDs) of methylphenidate dispensed; number of different pharmacies seen for dispensing of methylphenidate; number of prescribers consulted for a prescription of methylphenidate; and number of dispensings of methylphenidate. Data from the reimbursement database were analysed by clustering methods. These data were assessed from 2005 to 2008.

METHOD

The French General Health Insurance System (GHIS) database was used to obtain data on methylphenidate use in two French administrative areas. Individuals affiliated to the GHIS who had a prescription for methylphenidate reimbursed between 1 January and 31 March of 4 selected years (2005, 2006, 2007 and 2008) were included. After the first dispensing of methylphenidate for these individuals, all their dispensings (including methylphenidate and other psychoactive drugs) were monitored over a 9-month period. Following a descriptive analysis, a clustering method was used to identify different subgroups of subjects according to the methylphenidate consumer profile characteristics.

RESULTS

With regard to the number of patients who had a dispensing for methylphenidate during the first quarter of the year, an 84% increase was observed between 2005 (n = 640) and 2008 (n = 1175). The clustering method identified two subgroups. One of them was characterized by a higher number of dispensings, different prescribers and pharmacies and a greater total dispensed quantity, suggesting a deviant behaviour and, thus, possible abuse and diversion of methylphenidate. These subjects were older (aged 35.4 ± 11.3 years) and were more frequently patients receiving benzodiazepines, antidepressants, antipsychotics and maintenance opioid treatment. The proportion of subjects with a deviant behaviour increased from 0.5% in 2005 to 2% in 2007 and then decreased to 1.2% in 2008.

CONCLUSION

This method was able to assess the magnitude of methylphenidate abuse liability and to follow its evolution. The decrease in methylphenidate abuse and diversion seen between 2007 and 2008 can be explained by the enactment in April 2008 of specific regulations for prescription drugs (such as methylphenidate) that are deemed by the French government to have the potential for misuse; these regulations require the establishment of a 'contract of care' between the GHIS, prescriber and patient.