Injecting frequency trajectories and hepatitis C virus acquisition: Findings from a cohort of people who inject drugs in Montréal, Canada.

Background: Frequent injecting increases hepatitis C (HCV) acquisition risk among people who inject drugs (PWID). However, few studies have examined how temporal fluctuations in injecting frequency may effect HCV infection risk. Thus, this study examined HCV incidence according to injecting frequency trajectories followed by PWID over one year in Montréal, Canada.

Socioeconomic stability is associated with lower injection frequency among people with distinct trajectories of injection drug use.

Background: Little is known about how socioeconomic circumstances relate to injection frequencies among people who inject drugs (PWID) with diverse trajectories of injection. We aimed to characterize trajectories of injection drug use in a community-based sample of PWID over 7.5 years and to investigate the extent to which two modifiable factors reflecting socioeconomic stability-stable housing and stable income-relate to injection frequencies across distinct trajectories.

Associations between housing stability and injecting frequency fluctuations: findings from a cohort of people who inject drugs in Montréal, Canada.

Background: The relationship between housing stability and drug injecting is complex, as both outcomes fluctuate over time. The objectives were to identify short-term trajectories of housing stability and injecting frequency among people who inject drugs (PWID) and examine how patterns of injecting frequency relate to those of housing stability.

Methods: At three-month intervals, PWID enrolled between 2011 and 2016 in the Hepatitis Cohort completed an interviewer-administered questionnaire and were tested for hepatitis C and HIV infections.

Association between mental health service utilisation and sharing of injection material among people who inject drugs in Montreal, Canada.

Background: High-risk injection behaviors are associated with high prevalence of mental health problems among people who inject drugs (PWID). However, whether the use of mental health services is associated with lower risk of sharing injection material remains undetermined. This study aims to examine the association between mental health service utilisation and receptive sharing risk, and determine the potential modifying effect of psychological distress on this association.

Short and sporadic injecting cessation episodes as predictors of incident hepatitis C virus infection: findings from a cohort study of people who inject drugs in Montréal, Canada.

Background And Aims: For most people who inject drugs (PWID), drug injecting follows a dynamic process characterized by transitions in and out of injecting. The objective of this investigation was to examine injecting cessation episodes of 1-3-month duration as predictors of hepatitis C virus (HCV) acquisition.

Design: Cohort study.

6th Canadian Symposium on Hepatitis C Virus: Delivering a cure for hepatitis C infection-What are the remaining gaps?

Estimates are that more than 250,000 people in Canada are chronically infected with hepatitis C virus (HCV), and many more are unaware of their infection status. If untreated, chronic HCV infection can lead to cirrhosis and subsequent complications such as hepatocellular carcinoma. The Canadian Network on Hepatitis C, supported by the Public Health Agency of Canada and the Canadian Institutes of Health Research, has been committed to the scientific study of chronic hepatitis C and to supporting the advocacy work to improve diagnosis and access to HCV care in Canada.

High hepatitis C incidence in relation to prescription opioid injection and poly-drug use: Assessing barriers to hepatitis C prevention.

Background: Prescription opioid (PO) injection and poly-drug use have been associated with hepatitis C virus (HCV) infection among people who inject drugs (PWID). Poly-drug use is often a barrier to key HCV preventive programmes including opioid agonist treatment. The contribution of specific drug combinations to high HCV incidence in poly-drug users has not been assessed previously.

Short-term injection drug use changes following hepatitis C virus (HCV) assessment and treatment among persons who inject drugs with acute HCV infection.

Background: It is unclear whether treatment and care for hepatitis C virus (HCV) infection can help people who inject drugs (PWID) modify their injection drug use behaviours. This study examined changes in injection drug use among PWID with acute HCV systematically referred for HCV clinical assessment and treatment and offered targeted health care services, over the course of one year.

Methods: The study sample included PWID with documented acute HCV infection recruited and followed-up semi-annually at least twice in IMPACT (2007-2015), a longitudinal community-based prospective study in Montréal, Canada.

Depression, Anxiety, and Stress Among People With Chronic Hepatitis C Virus Infection and a History of Injecting Drug Use in New South Wales, Australia.

Objective: The aims of this study were to assess symptoms of depression, anxiety, and stress and associated sociodemographic factors among people living with chronic hepatitis C virus (HCV) infection with a history of injecting drug use and to assess the association between symptoms of depression, anxiety, or stress and HCV treatment intent, specialist assessment, or treatment uptake.

Methods: The Enhancing Treatment for Hepatitis C in Opioid Substitution Settings was an observational cohort study evaluating the provision of HCV assessment and treatment among people with chronic HCV and a history of injecting drug use, recruited from 9 community health centers and opioid substitution therapy (OST) clinics (New South Wales, Australia). Symptoms were assessed using the Depression Anxiety Stress Scales (DASS-21).

The effect of social functioning and living arrangement on treatment intent, specialist assessment and treatment uptake for hepatitis C virus infection among people with a history of injecting drug use: The ETHOS study.

Background: The objective was to assess social functioning and its association with treatment intent, specialist assessment and treatment uptake for hepatitis C virus (HCV) infection among people with a history of injecting drug use.

Methods: ETHOS is a prospective observational cohort evaluating the provision of HCV assessment and treatment among people with chronic HCV and a history of injecting drug use, recruited from nine community health centres and opioid substitution treatment clinics (NSW, Australia). Social functioning was assessed using a short form of the Opioid Treatment Index social functioning scale.

Cannabinoids reward sensitivity in a neurodevelopmental animal model of schizophrenia: a brain stimulation reward study.

The comorbidity schizophrenia and cannabis has a high prevalence. The consumption of cannabis is ten times higher among schizophrenia patients, suggesting that these patients could be differentially sensitive to its motivational effects. To study this question, we investigated the motivational effects of cannabinoid agonists using the brain stimulation reward paradigm and a neurodevelopmental model of schizophrenia: neonatal ventral hippocampus lesions (NVHL).

Opposite modulation of brain stimulation reward by NMDA and AMPA receptors in the ventral tegmental area.

Previous studies have shown that blockade of ventral tegmental area (VTA) glutamate N-Methyl-D-Aspartate (NMDA) receptors induces reward, stimulates forward locomotion and enhances brain stimulation reward. Glutamate induces two types of excitatory response on VTA neurons, a fast and short lasting depolarization mediated by α-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) receptors and a longer lasting depolarization mediated by NMDA receptors. A role for the two glutamate receptors in modulation of VTA neuronal activity is evidenced by the functional change in AMPA and NMDA synaptic responses that result from repeated exposure to reward.