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...

D-9-tetrahydrocannabinol (D-9-THC) and Cannabidiol (CBD), the two main ingredients of the Cannabis sativa plant have distinct symptomatic and behavioral effects. We used functional magnetic resonance imaging (fMRI) in healthy volunteers to examine whether D-9-THC and CBD had opposite effects on regional brain function. We then assessed whether pretreatment with CBD can prevent the acute psychotic symptoms induced by D-9-THC. Fifteen healthy men with minimal earlier exposure to cannabis were scanned while performing a verbal memory task, a response inhibition task, a sensory processing task, and when viewing fearful faces. Subjects were scanned on three occasions, each preceded by oral administration of D-9-THC, CBD, or...

Various psychiatric disorders such as major depression are associated with abnormalities in emotional processing. Evidence indicating involvement of the endocannabinoid system in emotional processing, and thus potentially in related abnormalities, is increasing. In the present study, we examined the role of the endocannabinoid system in processing of stimuli with a positive and negative emotional content in healthy volunteers. A pharmacological functional magnetic resonance imaging (fMRI) study was conducted with a placebo-controlled, cross-over design, investigating effects of the endocannabinoid agonist Δ9-tetrahydrocannabinol (THC) on brain function related to emotional processing in 11 healthy subjects. Performance and brain activity during matching of stimuli with a negative (‘fearful...

Endocannabinoids (ECBs) such as anandamide (AEA) act by activating cannabinoid type 1 (CB1) or 2 (CB2) receptors. The anxiolytic effect of drugs that facilitate ECB effects is associated with increase in AEA levels in several encephalic areas, including the prefrontal cortex (PFC). Activation of CB1 receptors by CB1 agonists injected directly into these areas is usually anxiolytic. However, depending on the encephalic region being investigated and on the stressful experiences, opposite effects were observed, as reported in the ventral HIP. In addition, contradictory results have been reported after CB1 activation in the dorsal HIP (dHIP). Therefore, in the present paper we have attempted to...

Objective: To review the main advances related to the potential therapeutic use of cannabinoid compounds in psychiatry. Method: A search was performed in the online databases PubMed, ScieELO, and Lilacs for studies and literature reviews concerning therapeutic applications of cannabinoids in psychiatry, especially cannabidiol, rimonabant, ∆9 -tetrahydrocannabinol, and their analogues. Results: Cannabidiol was found to have therapeutic potential with antipsychotic, anxiolytic, and antidepressant properties, in addition to being effective in other conditions. ∆9 -tetrahydrocannabinol and its analogues were shown to have anxiolytic effects in the treatment of cannabis dependence and to function as an adjuvant in the treatment of schizophrenia, although additional studies are...

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...