Unlike THC, CBD has no psychoactive effect, but can in fact counter the psychoactive effects of THC and other negative effects, such as inhibiting the THC-induced cognitive impairment in preclinical studies involving non-human primates [201]. In depression, anxiety, and stress, CBD has constantly been shown to induce anxiolytic and antidepressive potential [108,128,178]. CBD has also been shown to counter many of the effects of THC, including THC-induced anxiogenic effects [173,174,175,176,178,202]. Healthy participants have also reported decreased levels of subjective anxiety 90-min post administration of CBD. Some anxiolytic effects of CBD have been seen to be similar to the post-stress anxiolytic effects of isapirone, a selective 5-HT1A receptor partial agonist known for its antidepressant and anxiolytic effects [178,202]. The positive effects of CBD have also been shown in multiple other studies, such as those with healthy volunteers under psychological stress [108,203]. Neuroimaging studies have also confirmed that CBD administration decreased activity in limbic and paralimbic regions during emotional face processing tasks [175,178,204]. In Parkinson’s patients, CBD ameliorated the motor symptoms and also improved the quality of life of these patients [205].
