Britain's first medical cannabis clinic opened in Manchester this week despite only just four patients having successfully obtained cannabis-based treatments since their use was legalised in the country late last year.

The private clinic is Manchester will deal with patients suffering from chronic pain conditions, neurological condition such as epilepsy, Alzheimer's and Parkinson's disease and psychiatric problems including depression, anxiety and post-traumatic stress disorder.

"The legalisation of prescription cannabis has given people with chronic illnesses hope; the next step is to ensure the availability of medical cannabis to offer those without other alternatives the treatment they need," Hannah Simon from European Cannabis Holdings — the private investment group behind the new clinics — said in a statement.

Two other clinics are also expected to open in London and Birmingham later this spring.

Britain legalised some forms of cannabis-based products for medical use in November after two mothers whose sons suffer from severe epilepsy requested cannabis oil — which they said alleviates their boys' seizures — be made legal.

Both mothers admitted to illegally using the substance in the UK after procuring it from abroad.

A review was subsequently launched by the government which concluded that evidence showed medicinal marijuana had therapeutic benefits in certain cases.

Specialist doctors are now able to prescribe cannabis-derived medicinal products if there is clear evidence of benefit or if clinical needs cannot be met by a licenced medicine and where established treatment options have been exhausted, according to guidelines published by the National Health Services.

Only four patients have successfully accessed medical cannabis treatment since the change in the law. European Cannabis Holdings say the low figure is due to the strict prescription guidelines which it described as "barriers of access."

For Professor Barnes, Clinical Director of the Medical Cannabis Clinics, "these clinics represent a much-needed framework to enable access to treatments for a range of serious illness, and bring the UK in line with other countries when it comes to pain management."