A Long-term Safety Extension Study of Delta-9-tetrahydrocannabinol (THC) and Cannabidiol (CBD) in Multiple Sclerosis

Inclusion Criteria: * Aged at least 18 years. * Multiple Sclerosis of any type. * Stable Multiple Sclerosis symptomatology during the four weeks before study entry. * Symptoms of the required severity (\>50 mm on a 100 mm Visual Analogue Scale severity scale) in least one of the specified impairment categories; spasticity, muscle spasms, disturbed bladder control, neuropathic pain, limb tremor. * A stable medication regime during the four weeks before study entry. * Willing to abstain from cannabis or cannabinoids for at least seven days before study entry, and during the study. * Agreed either to use effective contraception during the study and for three months thereafter, or had been surgically sterilised or, if female, were post-menopausal. * Clinically acceptable laboratory results for pre-study screening. * Willing and able to undertake and comply with all study requirements. * Willing and able to read, consider and understand the subject information and consent form and give written informed consent. Subjects unable to read or to sign the document procedures were treated as detailed in the Declaration of Helsinki. * Willing for their general practitioner, and consultant if appropriate, to be informed of study participation. * Willing for their name to be notified to Home Office for participation in the study. Exclusion Criteria: * Known or strongly suspected to be abusing drugs, including alcohol. * Not prepared to abstain from cannabis or cannabinoids during the study. * Current or past addiction to cannabis. * Known or suspected to have had an adverse reaction to cannabinoids causing psychosis or other severe psychiatric illness. * History of any type of schizophrenia, any other psychotic illness, or other significant psychiatric illness or personality disorder other than depression associated with chronic illness. * Received any drug containing levodopa (Sinemet®, Sinemet plus®, Levodopa®, L-dopa®, Madopar®, Benserazide®). * Serious cardiovascular disorder including angina, uncontrolled hypertension, or an uncontrolled symptomatic cardiac arrhythmia. * Significant renal or hepatic impairment as shown in medical history or indicated by laboratory results. * History of epilepsy. * Terminal illness or other condition in which placebo medication would be inappropriate. * Pregnant, lactating or at risk of pregnancy. * Participated in any other clinical research study during the 12 weeks before study entry. * Planned hospital admission between study entry and Visit 6. * Planned travel outside the UK between study entry and Visit 6.