The current evidence suggests a sleep promoting effect of THC. Although, there is some support from pre-clinical and small sample size human studies suggesting a direct sleep enhancing effect, it remains unclear from the larger clinical trials, whether improved sleep is an epiphenomena secondary to improvements in the primary outcome measures ( i.e., pain, nausea or spasticity). There are no studies evaluating the sleep promoting effects of THC or analogues in patients with primary insomnia or objectively evaluating sleep at baseline and following treatment with THC or analogues in patients suffering from chronic pain disorder and insomnia. Cannabinoids have the potential of simultaneously improving sleep and lessening chronic, non-malignant pain, thereby interrupting the vicious cycle of pain and sleep disturbance. An investigation of the efficacy of cannabinoids in treating insomnia in chronic, non-malignant pain patients is therefore warranted.