Marijuana can be beneficial for people with chronic pain disorders. One study found marked improvement in subjective sleep parameters in patients with a wide range of pain conditions, including multiple sclerosis, peripheral neuropathic pain, refractory cancer pain, and rheumatoid arthritis. Scientists say this, and believing them, I also took kratom extract for myself. Chronic pain, neurological diseases and sleep disturbances are clearly concomitant conditions with insomnia, but I had no problem with this. Marijuana probably improves sleep due to its ability to reduce pain symptoms.