Patterns and Correlates of Injecting Among Heroin Users: A 11-Year Follow-up of the Australian Treatment Outcome Study Cohort

The Effects of Neighborhood Disorder on Polydrug Use: Examining Depressive Symptoms and Deviant Peer Association as Mediating Mechanisms

Neighborhood disorder is a risk factor for substance use, but research is limited with regard to the effect of such disorder on polydrug use. Further, research on potential mechanisms underlying this relationship is similarly limited. The current study examined the direct effect of neighborhood disorder on drug use variety and examined deviant peer association and depressive symptoms as mediators among a sample of justice-involved youth. The first three waves of the Pathways to Desistance study were analyzed. Generalized structural equation modeling was used to test for direct and indirect effects of interest. A bootstrap resampling process was used to compute standard errors and significance of hypothesized mediation effects. Findings indicated that greater levels of neighborhood disorder were associated with increased drug use variety. This effect was attenuated by 15% when mediating pathways were included in the model. Only deviant peer association significantly mediated this relationship and accounted for the majority of the total mediating effect. These results indicated that justice-involved youth exposed to neighborhood disorder are at elevated risk for polydrug use and that increased deviant peer association helps to explain this relationship.

Antisocial personality disorder as a predictor of polydrug use: a longitudinal study of the dual mediating roles of deviant peer association and self-control among juvenile offenders

BACKGROUND

Antisocial personality disorder (APD) has been linked to increased risk for polydrug use (PU). However, there is a dearth of research focusing on the mechanisms underlying this risk.

AIMS

To examine the relationship between APD and PU; to test for the mediating effects of deviant peer association (DVA) and self-control in this relationship; to determine if the magnitudes of observed mediation effects are equivalent.

METHODS

The Pathways to Desistance data were analyzed. Generalized structural equation modeling tested for direct and mediating relationships. Mediation effect equivalence was tested using a Clogg Z test.

RESULTS

Antisocial personality disorder was associated with increased drug use heterogeneity (coefficient = 0.479; CI = 0.107-0.851). This was significantly mediated by self-control and DVA. The magnitude of the mediation was significantly stronger for the self-control path (self-control coefficient = 0.233; CI = 0.044-0.422; DVA coefficient = 0.134; CI = 0.028-0.241).

CONCLUSION

While both self-control and DVA were found to be important for explaining PU in APD, it may be beneficial to focus on self-control to address this problem.

Rates, characteristics and toxicology of cocaine-related deaths in Australia, 2000-2021

AIMS

To (i) assess the population mortality rates of cocaine-related deaths in Australia, 2000 to 2021; (ii) determine the circumstances of death and case characteristics; and (iii) determine their toxicological profile.

DESIGN

Retrospective study of cocaine-related deaths in Australia, 2000 to 2021, retrieved from the National Coronial Information System.

SETTING

Australia-wide.

CASES

A total of 884 cases, mean age = 33.8 (SD, 10.0) years and 86.5% (n = 765) male.

MEASUREMENTS

Information was collected on characteristics, manner of death and toxicology. Only cases in which the presence of blood cocaine and/or metabolites were included.

FINDINGS

Population rates did not significantly increase during 2001-2011 (annual percentage change [APC] = 1.5; CI, -3.2, 6.5), but from 2012, there was a marked acceleration (APC = 20.0, 95% CI, 15.5, 25.3). Circumstances of death were unintentional drug toxicity (70.7%, n = 625), intentional self-harm (17.8%, n = 157), traumatic accident (11.5%, n = 102). The proportion of cases constituted by unintentional toxicity declined across the study period (APC = -2.6; CI, -3.1, -2.1). There was a substantial decline in the proportion of cases with a history of injecting drug use (APC = -5.7; CI, -6.5, -4.9) and with a history of substance use problems (APC = -3.2; CI, -3.9, -2.5). Both cocaine (0.100 vs 0.050 mg/L, P < 0.001) and benzoylecgonine (0.590 vs 0.240 mg/L, P < 0.001) concentrations were higher amongst toxicity cases than in cases of death from traumatic injury. Cocaethylene was present in 26.4% (n = 233), levamisole in 18.6% (n = 164) and lignocaine in 11.5% (n = 102). Psychoactive drugs in addition to cocaine were present in 92.9% (n = 821), most commonly opioids (50.5%, n = 446), alcohol (47.1%, n = 416), hypnosedatives (43.2%, n = 382) and psychostimulants (30.3%, n = 268). There was a steady decline in the proportion of opioid positive cases (APC = -5.4; CI, -6.3, -4.5).

CONCLUSIONS

There was a large increase in cocaine-related deaths across Australia from 2000 to 2021. This was accompanied by changes in case profiles, with histories of injecting drug use and substance use problems, as well as recent opioid use, becoming less prominent.

Borderline Personality Disorder as a Predictor of Drug Use Variety: Cognitive Vs. Affective Mechanisms

Borderline personality disorder has been identified as a risk factor for polydrug use. Despite this, there remains a lack of understanding of which characteristics of the disorder provide the mechanisms for this relationship. This study examined a set of constructs as mechanisms explaining the borderline personality disorder-polydrug use relationship that are divided into affective and cognitive categories. The Pathways to Desistance data were used in analyses. Generalized structural equation modeling was used to examine the direct relationship between borderline personality disorder and test for attenuation of this direct effect. A bootstrap resampling process was used to estimate standard errors utilized to specify specific and total indirect effects of mechanism variables and their significance level. Results indicated that greater symptom severity of borderline personality disorder predicted increased drug use variety. This relationship was attenuated by 70% when hypothesized mechanisms were included and became nonsignificant. It appeared that this attenuation was mainly due to sensation-seeking. Findings indicate that interventions for individuals suffering from borderline personality disorder with polydrug use issues may find utility in structuring programming around mitigating sensation-seeking.

PTSD as a Risk Factor Predicting Polydrug Use: A Dual Systems of Self-Control Mediation Model

Post-traumatic stress disorder (PTSD) is associated with increased risk for polydrug use. Low self-control is a key characteristic of the disorder and is predictive of polydrug use. However, there is a dearth of research focused on the relevance of a dual systems model delineation of self-control into the constructs of risk-seeking and impulsivity as it pertains to polydrug use and PTSD. This study tested dual systems mediation of this relationship. Generalized structural equation modeling was used to test for mediation effects. Results indicated that more PTSD symptoms predicted increased drug use variety (coefficient = 0.024; confidence interval [CI] = [0.001, 0.046]). Inclusion of dual systems constructs fully attenuated this relationship. The total indirect effect achieved marginal significance (coefficient = 0.005; CI = [>−0.001, 0.009]). Sensitivity analyses of the specific indirect effect of impulsivity as the sole mediator indicated significant mediation. These results provide some indication that impulsivity-based programming may help to treat polydrug use among those with severe PTSD.