“Treatment of neuropathic pain (NP) symptoms associated with multiple sclerosis (MS) is frequently insufficient. Yet, cannabis is still rarely offered for treatment of pain. This clinical trial aimed at showing the positive benefit-risk ratio of dronabinol. Two hundred forty MS patients with central NP entered a 16-weeks placebo-controlled phase-III study followed by a 32-weeks open-label period. One hundred patients continued therapy for overall up to 119 weeks. Primary endpoint was change of pain intensity on the 11-point Numerical Rating Scale over a 16-weeks treatment period. Safety was assessed on the basis of adverse reactions (ARs), signs of dependency and abuse. Pain intensity during 16-weeks dronabinol and placebo treatment was reduced by 1.92 and 1.81 points without significant difference in between (p = 0.676). Although the proportion of patients with ARs was higher under dronabinol compared to placebo (50.0 vs. 25.9%), it decreased during long-term use of dronabinol (26%). No signs of drug abuse and only one possible case of dependency occurred. The trial results demonstrate that dronabinol is a safe long-term treatment option.” https://www.ncbi.nlm.nih.gov/pubmed/29073592
“Overall, this trial demonstrated the long-lasting therapeutic potential, the good tolerability and favourable safety profile of dronabinol – especially in terms of drug abuse and dependency. Based on the presented results, there is no special focus on the harm caused by dronabinol treatment. Although the statistical proof of efficacy for dronabinol versus placebo treatment is pending, physicians should consider the potential benefits of the multifactorial effects of dronabinol.” https://www.karger.com/Article/FullText/481089
“Multiple sclerosis (MS) is a chronic inflammatory and demyelinating disorder of the central nervous system (CNS) that can cause cognition, mobility, and sensory impairments. It is considered one of the most common non-traumatic causes of disability in the world.
The aim of the present article was to review the clinical evidence related to medicinal plants in the management of MS symptoms.
Electronic databases, including the Cochrane Library, Pubmed, and Scopus, were searched for entries from 1966 to February 2017. Only clinical studies were included in this review. Different medicinal plants have positive effects on MS, including Andrographis paniculata, Boswellia papyrifera, Ruta graveolens, Vaccinium spp., Camellia sinensis, Panax ginseng, Aloysia citrodora, Ginkgo biloba, Oenothera biennis, and Cannabis sativa.
C. sativa had the highest level of clinical evidence, supporting its efficacy in MS symptoms.
Proanthocyanidins, ginkgo flavone glycosides, ginsenosides, epigallocatechin-3-gallate, 
“Neurogenesis is influenced by various external factors such as enriched environments. Some researchers had postulated that neurogenesis has contributed to the hippocampal learning and memory. This project was designed to observe the effect of Delta-9-tetrahydrocannabinol (∆9-THC) in cognitive performance that influenced by the neurogenesis.
Different doses of ∆9-THC were used for observing the neurogenesis mechanism occurs in the hippocampus of rats. The brains were stained with antibodies, namely BrdU, glial fibrillary acidic protein (GFAP), nestin, doublecortin (DCX) and class III β-tubulin (TuJ-1). The cognitive test was used novel-object discrimination test (NOD) while the proteins involved, DCX and brain-derived neurotrophic factor (BDNF), were measured.
Throughout this study, ∆9-THC enhanced the markers involved in all stages of neurogenesis mechanism. Simultaneously, the cognitive behaviour of rat also showed improvement in learning and memory functions observed in behavioural test and molecular perspective.
Administration of ∆9-THC was observed to enhance the neurogenesis in the brain, especially in hippocampus thus improved the cognitive function of rats.”