Apart from the interaction with the endocannabinoid system through alteration of endocannabinoid signaling, the effect of CBD on drug addiction has been shown to involve modest affinity agonist action at 5-HT1A receptors . So far, two studies have examined the effects of CBD in adult cannabis users . A pragmatic open-label clinical trial evaluated the effect of 10 weeks of 200 mg daily CBD administration on psychological symptoms and cognition in adults with frequent cannabis use , while participants continued cannabis use . Compared with baseline, participants reported fewer depressive and psychotic symptoms, but more state anxiety symptoms after CBD treatment, and demonstrated improvement in attentional switching, verbal learning, and memory. CBD was well tolerated with no reported side effects, in line with a recent meta-analysis of CBD clinical trials reflecting that CBD tends to be very well-tolerated with few serious adverse effects. Participants retrospectively reported reduced euphoria when smoking cannabis, in line with previous studies showing that CBD reverses the reinforcing effects of cannabis in youth . The study provided the first evidence that prolonged CBD treatment may improve psychological symptoms and cognitive function in frequent users, with greater benefits in dependent than in nondependent cannabis users.
However, the study lacked a placebo control and was not designed to examine effects on cannabis use. Recently,cannabis grow lights Freeman and colleagues offered the first empirical data supporting that a treatment package comprised of CBD + MI was able to engage non-treatment seeking adults with CUD and reduce post-treatment cannabis use. In a phase 2a dose-finding RCT, they found that synthetic CBD over a 4-week treatment period outperformed placebo at daily doses of 400 mg or 800 mg ; eliminated at interim analysis due to inefficacy) in reducing biological and self-report metrics of cannabis use among a sample of non-treatment seeking adults with CUD, who wanted to quit cannabis use. Reductions in use were maintained up to 24 weeks following treatment with 400 mg CBD. Results on secondary outcomes were mixed. However, there was some evidence for CBD reducing cigarette use, cannabis withdrawal symptoms, and anxiety. By contrast, there was no evidence for changes in alcohol use, and there was evidence for a decrease in sleep quality following CBD treatment. Importantly, in terms of potential disruption in functioning, use of CBD was not associated with more adverse events than placebo – in line with the open-label trial . Furthermore, the study showed impressive retention rates with 94 % retention throughout the study period.
To summarize, very few studies have examined the effect of non-THC based cannabinoid treatment strategies on CUD to date, but evidence from the first studies is promising. In the first placebo-controlled RCT in adults with cannabis dependence, FAAH inhibitors reduced withdrawal symptoms and cannabis use compared to placebo, cannabis grow tent with no difference in adverse outcomes between groups. A pragmatic open label trial of CBD in adults who continued their frequent cannabis use found improvements in depressive and psychotic symptoms, attention, learning and memory, and reduced euphoria when smoking cannabis. In the first placebo-controlled RCT of CBD in adults with cannabis dependence, CBD reduced cannabis use, with no difference in adverse outcomes between groups.As reviewed in Section 5.1, evidence from randomized placebo-controlled studies suggests that treatment with synthetic THC decreases withdrawal symptoms, but not cannabis use, in adults with daily cannabis use or CUD.
Further, the same studies suggest that higher doses of THC may increase cannabis intoxication and liking, while the evidence regarding THC combined with CBD is more mixed. The lack of effect on cannabis use and abstinence in adult studies with synthetic THC conducted so far, including studies where THC is administered concomitantly with MI/CBT up to 12 weeks, suggests that the efficacy of synthetic THC as a treatment among youth with CUD should not be tested as a stand-alone pharmacological treatment. The relatively consistent effect on withdrawal symptoms may suggest potential for combining dronabinol or nabilone with other medications, however, this should be weighed against potential negative outcomes associated with administering THC in youth samples. More specifically, the evidence from laboratory studies suggests that higher doses of THC may increase cannabis intoxication and drug liking, which naturally raises concern, as these effects may pose a risk for relapse in patients who have stopped using cannabis and may be even more problematic in patients that aim to reduce, but not stop, using cannabis.