Psychedelic drug LSD could be used as an effective method to treat alcoholism, scientists say.

The use of lysergic acid diethylamide (LSD), coupled with relapse prevention treatments, could help alcoholics steer clear of the bottle, research published in the Journal of Psychopharmacology suggests.

Teri Krebs and Pal-Orjan Johansen, who were performing research fellowships at Harvard Medical School in the US, examined a number of previous studies, mostly from the 1960s and 1970s, and found that a number of clinics used LSD to treat alcoholism with some success.

They said they found evidence for a clear and consistent beneficial effect of a low dose of LSD for treating alcohol dependency.

They examined 536 participants, across six medical trials, and found that 59% of LSD patients had improved compared to 38% of control patients.

Researchers said the positive effects of a single dose of the drug, tested by a standardised assessment of problem alcohol use, appeared to last for up to 12 months.

However, they suggested the repeated use of the medication, coupled with preventative treatments, might provide more sustained results.

Investigators of one trial which was examined said: "It was rather common for patients to claim significant insights into their problems, to feel that they had been given a new lease on life, and to make a strong resolution to discontinue their drinking."

Mr Johansen said: "Given the evidence for a beneficial effect of LSD on alcoholism, it is puzzling why this treatment approach has been largely overlooked."