Although the long-term effects of cannabis and its derivatives are not completely known, except on the part of the long-time users of cannabis themselves, the medical potential for cannabis and cannabis-based products have been suggested by multiple observational, open-label studies, and a few RCTs [108,128] (Table 2). The presumed medicinal indications cover a large array of conditions, including chronic pain, epilepsy, insomnia, cancer-associated pain, vomiting and nausea in cancer and HIV patients, PTSD, Parkinson’s disease (PD), depression, anxiety, and stress, among others [164]. These studies, however, contain multiple weaknesses, as several recent systematic reviews and meta-analyses have found [108,109,128]. Nevertheless, among the multiple constituents of cannabis, THC and CBD have been the most subject to different investigations in animal models and trials in humans. There are also some studies of synthetic cannabinoids or endogenous cannabinoids [5,108,128,167,168,169]. In general, cannabis and its derivatives seem to be well tolerated by humans and animals alike when used at relatively low doses and during short time periods [168,169,170]. Under these conditions, they are usually linked to many positive therapeutic effects for a wide range
