I have read about studies from Europe (not very specific I know) that suggest CBD might work better for some people if combined with some level of THC. Also, the getting high part can be helpful, although not for everybody, of course. A second point – I don’t hear very much about CBD eliminating or almost eliminating pain for people with severe pain. Helpful, but, so far at least, it doesn’t seem that CBDs can replace opioids or substantially reduce pain for all chronic pain patients. Maybe someday.
The immediate and powerful effects of THC are explained because of the special affinity it has with the CB1 type receptors, which mediate crucial processes in the brain. The less prominent (but no less important) action of CBD was explained, at least for a while, by hypothesizing that it binds to CB2 type receptors, hence its more diffuse manner of exercising changes in the body. Early on, the antipsychotic effects of cannabidiol were observed, an aspect which seemed to be in consonance with this initial hypothesis.
This isn’t new but had to be mentioned. One of the major and well-known benefits of cannabis is its ability to treat pain and helping with pain management. It has the capabilities of assisting with chronic pain as well as inflammation. Furthermore, it has been found to help patients deal with severe rheumatism and arthritis as well as other chronic pains.

Furthermore, this number is expected to grow. According to the CDC, it is estimated that by 2040, over 78 million adults will have arthritis that has been diagnosed by a doctor, with 43% of those individuals limited in terms of activity because of the disease, without taking into effect other conditions that contribute to arthritis side effects, like growing obesity numbers and more.

Due to the uniqueness of everyone’s endocannabinoid system, CBD does not affect any two people the same way. There are a host of factors that influence its efficacy, including genetics, previous history of use, general health, weight, ethnicity and so on. Therefore, while one person may find that 15 mg of CBD a day works wonders for suppressing appetite and boosting weight loss, another may require up to 100 mg (or more) in order to achieve the same results (in fact, they may not experience any results at all).

Currently, the only CBD product approved by the Food and Drug Administration is a prescription oil called Epidiolex. It's approved to treat two types of epilepsy. Aside from Epidiolex, state laws on the use of CBD vary. While CBD is being studied as a treatment for a wide range of conditions, including Parkinson's disease, schizophrenia, diabetes, multiple sclerosis and anxiety, research supporting the drug's benefits is still limited.
To my understanding, neither CBD nor THC are effective for “severe” pain; rather, they work better for mild to moderate chronic pain. Often, with severe pain, the dosage of opiates can be decreased with concomitant use of medical cannabis or CBD and that decrease in dose makes their use safer. Concurrent use of THC does increase the analgesic effect of CBD, but it also adds the “high” which some people do not want as a side effect.
More recent experiments, involving the administration of a part CBD part THC solution, have yielded results that contradict the first supposition. At present, on the evidence that cannabidiol reduces some of the psychoactive effects of tetrahydrocannabinol (acting as a de facto antidepressant), scientists argue that cannabidiol has a holistic but indirect influence on all cannabinoid receptors in the endocannabinoid system. The main consequence of this impact seems to be an increase in the production of endocannabinoids. This is now the prevailing idea that accounts for the mountains of empirical evidence of how the benefits of cannabidiol are expressed at the cellular level.