Publications by authors named "Rachel A Rabin"

Objective: Since the federal Canadian government legalized cannabis in 2018, cannabis use in the general population has slightly increased. However, little is known about the impact of cannabis legalization on pattens of cannabis use in psychiatric populations.

Method: We studied changes in daily/almost daily and average 30-day cannabis use amongst individuals currently using cannabis who reported past 12-month experiences of specific mental health disorders and among those without past 12-month experiences of any mental health disorder before and after Canadian legalization of recreational cannabis use ( = 13,527).

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Objectives: Cannabis legalization has triggered an increase in prenatal cannabis use. Given that tobacco is commonly co-used with cannabis, determining outcomes associated with prenatal cannabis and tobacco co-exposure is crucial. While literature exists regarding the individual effects of prenatal cannabis and tobacco exposure on childhood behaviour, there is a gap regarding their combined use, which may have interactive effects.

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Article Synopsis
  • Dopamine plays a critical role in addiction, with its functioning disrupted at all stages of the addiction process, potentially indicated by neuromelanin levels in the substantia nigra.
  • A systematic review identified 10 relevant articles examining neuromelanin in substance use disorders, with a meta-analysis showing inconclusive results due to insufficient sample size and power.
  • The analysis underscores the need for more robust replication studies and research on neuromelanin in relation to various substances and associated psychiatric conditions.
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Effects of Repetitive Transcranial Magnetic Stimulation (rTMS) on Cannabis Use and Cognitive Outcomes in SchizophreniaURL: www.clinicaltrials.gov; Registration Number: NCT03189810.

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Background And Objectives: Rates of cannabis use disorder (CUD) are higher in people with schizophrenia than in the general population. Irrespective of psychiatric diagnosis, tobacco co-use is prevalent in those with CUD and leads to poor cannabis cessation outcomes. The cannabis withdrawal syndrome is well-established and increases cannabis relapse risk.

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Repetitive transcranial magnetic stimulation (rTMS) is a promising treatment for cannabis use disorder in schizophrenia; however, gaps in the literature remain as to the potential role of neurocognitive functioning in treatment response. We evaluated the moderating role of select cognitive functions including baseline executive functioning, verbal memory, and sustained attention, and we explore the mediating role of changes in task performance on changes in cannabis use in both active and sham rTMS groups. Participants underwent high-frequency (20 Hz) rTMS applied to the bilateral dorsolateral prefrontal cortex 5x/week for 4 weeks.

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Background And Objectives: Cannabis is a widely used substance that may impair select cognitive domains, including attention and memory. Problematic cannabis use is a common clinical problem among patients with major depressive disorder (MDD). Few studies have investigated the effects of cannabis abstinence on cognition in MDD.

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Background: People with schizophrenia (SCZ) have significantly higher tobacco smoking rates and lower quit rates than the general population. Varenicline, a partial agonist at α4β2 nicotinic acetylcholine receptors (nAChRs) is an effective smoking cessation pharmacotherapy, however, investigation into its effects in SCZ are less well-studied and mechanisms may differ from non-psychiatric controls due to dysregulation in nAChR neurotransmission associated with SCZ. Here, we investigate whether Varenicline attenuates acute abstinence-induced increases in craving and withdrawal in participants with and without SCZ.

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Cannabis use disorder (CUD) occurs at high rates in schizophrenia, which negatively impacts its clinical prognosis. These patients have greater difficulty quitting cannabis which may reflect putative deficits in the dorsolateral prefrontal cortex (DLPFC), a potential target for treatment development. We examined the effects of active versus sham high-frequency (20-Hz) repetitive transcranial magnetic stimulation (rTMS) on cannabis use in outpatients with schizophrenia and CUD.

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Background: Neuroimaging studies reveal structural and functional including neurochemical brain abnormalities in individuals with substance use disorders compared to healthy controls. However, whether and to what extent such dysfunction is reversible with abstinence remains unclear, and a review of studies with longitudinal within-subject designs is lacking. We performed a systematic review of longitudinal neuroimaging studies to explore putative brain changes associated with abstinence in treatment-seeking individuals with substance use disorders.

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Background: While males are more likely diagnosed with cannabis use disorder (CUD), females are more susceptible to developing and maintaining CUD. Yet, for both sexes, CUD is associated with high rates of comorbid mental illness (MI).

Objectives: To identify and compare sex differences in the prevalence of comorbid CUD amongst individuals with/without MIs.

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Rationale: Emotion recognition is impaired in drug addiction. However, research examining the effects of cocaine use on emotion recognition yield mixed evidence with contradictory results potentially reflecting varying abstinence durations.

Objectives: Therefore, we investigated emotion recognition and its neural correlates in individuals with cocaine use disorder (CUD) parsed according to abstinence duration.

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Purpose Of The Review: The goal of this article is to summarize the treatment-focused literature on cannabis and tobacco co-use and the treatment implications of co-use. This review will focus on: 1) the impact of co-use on cessation outcomes, 2) compensatory use/substitution of the non-treated substance among co-users, and 3) treatment interventions to address co-use. This article will highlight the limitations to co-use captured in the literature and offer considerations and directives for co-use research and treatment moving forward.

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Gray matter volume (GMV) in frontal cortical and limbic regions is susceptible to cocaine-associated reductions in cocaine-dependent individuals (CD) and is negatively associated with duration of cocaine use. Gender differences in CD individuals have been reported clinically and in the context of neural responses to cue-induced craving and stress reactivity. The variability of GMV in select brain areas between men and women (e.

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Background: Tobacco and cannabis are highly co-morbid in the general population and in patients with schizophrenia. Given the putative causal mechanisms facilitating co-use, it is important to determine how cannabis cessation may influence concurrent tobacco use. Using a 28-day cannabis abstinence paradigm, we prospectively examined changes in tobacco consumption in patients with schizophrenia and controls with cannabis dependence and daily cigarette use.

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Background: Cannabis use disorders (CUD) are common in schizophrenia (~25%) compared to the general population (~3%). Tetrahydrocannabinol (THC), the principal psychoactive component in cannabis is fat-soluble, resulting in an extended period for cannabinoid elimination. While detection of cannabinoids in urine is indicative of prior cannabis exposure, time of last use is difficult to verify sustained abstinence for extended periods (e.

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Cross-sectional studies of the effects of cannabis on cognition in schizophrenia have produced mixed results. Heavy and persistent cannabis use in schizophrenia is a common clinical problem, and effects of controlled abstinence from cannabis in these patients have not been carefully evaluated. The present study sought to determine the effects of cannabis abstinence on cognition in patients with schizophrenia and co-occurring cannabis dependence.

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Background: Rates of cannabis use among patients with schizophrenia are high, however little is understood about clinical effects of continued cannabis use and cessation after illness onset. Therefore, we investigated the effects of 28-days of cannabis abstinence on psychotic and depressive symptomatology in cannabis dependent patients with schizophrenia.

Method: Males with cannabis dependence and co-morbid schizophrenia (n=19) and non-psychiatric controls (n=20) underwent 28-days of monitored cannabis abstinence.

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Background: Cannabis is the most commonly used illicit substance among patients with schizophrenia. Cannabis exacerbates psychotic symptoms and leads to poor functional outcomes. Dysfunctional cortical inhibition has been implicated in the pathophysiology of schizophrenia; however, the effects of cannabis on this mechanism have been relatively unexamined.

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Background And Objective: Tobacco and cannabis are frequently used in combination and cannabis co-use may lead to poor tobacco cessation outcomes. Therefore, it is important to explore if cannabis co-use is associated with a reduced likelihood of achieving successful tobacco abstinence among treatment-seeking tobacco smokers. The present study examined whether current cannabis use moderated tobacco cessation outcomes after 12 weeks of pharmacological treatment (varenicline vs.

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