Abstract Background Medicinal cannabis has received increased research attention over recent years due to loosening global regulatory changes. Medicinal cannabis has been reported to have potential efficacy in reducing pain, muscle spasticity, chemotherapy-induced nausea and vomiting, and intractable childhood epilepsy. Yet its potential application in the field of psychiatry is lesser known. Methods The first clinically-focused systematic review on the emerging medical application of cannabis across all major psychiatric disorders was conducted. Current evidence regarding whole plant formulations and plant-derived cannabinoid isolates in mood, anxiety, sleep, psychotic disorders and attention deficit/hyperactivity disorder (ADHD) is discussed; while also detailing clinical prescription considerations (including pharmacogenomics), occupational...

Abstract   Recreational marijuana laws (RMLs) continue to grow in popularity, but the effects on mental health treatment are unclear. This paper uses an event-study within a difference-in-differences framework to study the short-run impact of state RMLs on admissions into mental health treatment facilities. The results indicate that shortly after a state adopts an RML, they experience a decrease in the average number of mental health treatment admissions. The findings are driven by white, Black, and Medicaid-funded admissions and are consistent for both male and female admis- sions. The results are robust to alternative specifications and sensitivity analysis.

Abstract   Background Cannabis use may be linked with anhedonia and apathy. However, previous studies have shown mixed results, and few have examined the association between cannabis use and specific reward sub-processes. Adolescents may be more vulnerable than adults to harmful effects of cannabis. This study investigated (1) the association between non-acute cannabis use and apathy, anhedonia, pleasure, and effort-based decision-making for reward; and (2) whether these relationships were moderated by age group.   Methods We used data from the “CannTeen” study. Participants were 274 adult (26–29 years) and adolescent (16–17 years) cannabis users (1–7 d/wk use in the past 3 months) and gender-...

Abstract   The marijuana amotivational syndrome posits that cannabis use fosters apathy through the depletion of motivation-based constructs such as self-efficacy. The current study pursued a two-round design to rule out concomitant risk factors responsible for the connection from marijuana intake to lower general self-efficacy. College students (N = 505) completed measures of marijuana use, demographics (age, gender, and race), personality (extraversion, agreeableness, conscientiousness, openness, and neuroticism), other substance use (alcohol and tobacco), and general self-efficacy (initiative, effort, and persistence) in two assessments separated by a month. Hierarchical regression models found that marijuana use forecasted lower initiative and persistence, even after statistically ruling out...

Abstract   Although little evidence supports cannabis-induced amotivational syndrome, sources continue to assert that the drug saps motivation 1, which may guide current prohibitions. Few studies report low motivation in chronic users; another reveals that they have higher subjective wellbeing. To assess differences in motivation and subjective wellbeing, we used a large sample (N = 487) and strict definitions of cannabis use (7 days/week) and abstinence (never). Standard statistical techniques showed no differences. Robust statistical methods controlling for heteroscedasticity, non-normality and extreme values found no differences in motivation but a small difference in subjective wellbeing. Medical users of cannabis reporting health problems tended to...

Abstract   Rationale: Stress is a risk factor for psychosis and treatments which mitigate its harmful effects are needed. Cannabidiol (CBD) has antipsychotic and anxiolytic effects.   Objectives: We investigated whether CBD would normalise the neuroendocrine and anxiety responses to stress in clinical high risk for psychosis (CHR) patients.   Methods: Thirty-two CHR patients and 26 healthy controls (HC) took part in the Trier Social Stress Test (TSST) and their serum cortisol, anxiety and stress associated with public speaking were estimated. Half of the CHR participants were on 600 mg/day of CBD (CHR-CBD) and half were on placebo (CHR-P) for 1 week.   Results: One-way analysis of variance...

Abstract Introduction: Chronic cannabis use has been associated with impaired cognition and elevated psychological symptoms, particularly psychotic-like experiences. While D9-tetrahydrocannabinol (THC) is thought to be primarily responsible for these deleterious effects, cannabidiol (CBD) is purported to have antipsychotic properties and to ameliorate cognitive, symptomatic, and brain harms in cannabis users. However, this has never been tested in a prolonged administration trial in otherwise healthy cannabis users. Here, we report the first study of prolonged CBD administration to a community sample of regular cannabis users in a pragmatic trial investigating potential restorative effects of CBD on psychological symptoms and cognition. Materials and Methods: Twenty frequent...

Abstract Background: The therapeutic application of cannabidiol (CBD) is gaining interest due to expanding evidence for its use. Objective: To summarize the clinical outcomes, study designs and limitations for the use of CBD and nabiximols (whole plant extract from Cannabis sativa L. that has been purified into 1:1 ratio of CBD and delta-9- tetrahydrocannabinol) in the treatment of psychiatric disorders. Materials and method: A systematic review was conducted including case reports, case series, open-label trials, non-randomized and randomized controlled trials (RCTs). The search resulted in 23 relevant studies on CBD and nabiximols in the treatment of a wide range of psychiatric disorders. The quality...

Background: Among the many cannabinoids in the cannabis plant, cannabidiol (CBD) is a compound that does not produce the typical subjective effects of marijuana.   Objectives: The aim of the present review is to describe the main advances in the development of the experimental and clinical use of cannabidiol CBD in neuropsychiatry.   Methods: A non-systematic search was performed for studies dealing with therapeutic applications of CBD, especially performed by Brazilian researchers.   Results: CBD was shown to have anxiolytic, antipsychotic and neuroprotective properties. In addition, basic and clinical investigations on the effects of CBD have been carried out in the context of many other health conditions, including...

Maternal deprivation in rats specifically leads to a vulnerability to opiate dependence. However, the impact of cannabis exposure during adolescence on this opiate vulnerability has not been investigated. Chronic dronabinol (natural delta-9 tetrahydrocannabinol, THC) exposure during postnatal days 35–49 was made in maternal deprived (D) or non-deprived (animal facility rearing, AFR) rats. The effects of dronabinol exposure were studied after 2 weeks of washout on the rewarding effects of morphine measured in the place preference and oral self-administration tests. The preproenkephalin (PPE) mRNA levels and the relative density and functionality of CB1, and m-opioid receptors were quantified in the striatum and the mesencephalon. Chronic...