Lithium doesn't help patients with ALS, or Lou Gehrig's disease, contrary to previous study results, new research says.

Results from a small study published two years ago suggested the drug, often used for depression, could slow the fatal neurological disorder. Many ALS sufferers and their families rushed to try it, spearheading a patient-led effort to test lithium without doctors.

'There's no rush for patients to take lithium.'— Dr. Swati Aggarwal

In the first trial to scientifically assess whether lithium works for Lou Gehrig's disease, doctors found it had no effect — and stopped the study early because it seemed futile. The results were published online Tuesday in the medical journal, Lancet Neurology.

American and Canadian doctors enrolled 84 patients with Lou Gehrig's disease into their study across both countries. About half the patients got lithium and riluzole, the standard drug used for the disease. The other half got riluzole plus placebo pills.

After nearly six months, researchers didn't see any difference: 22 of the 40 patients in the lithium group had become worse versus 20 of 44 patients in the placebo group. Patients on lithium were more likely to have fallen and suffer back pain.

"There's no rush for patients to take lithium," said Dr. Swati Aggarwal, a neurologist at Massachusetts General Hospital and the study's lead researcher. "It clearly does not have a big effect."

Lou Gehrig's disease attacks the brain and spinal cord. The disease is estimated to affect two people in every 100,000, including about 30,000 Americans and 3,000 Canadians, many of whom have trouble walking, talking and eating.

Riluzole is the only drug approved for the disease, and can sometimes slow progression by a few months. Most patients live only a few years after being diagnosed.

How does ALS evolve?

Michael Swash, a neurologist from Barts and the London School of Medicine and Dentistry in London, said it was time to close the door on lithium.

"The problem with a disease like ALS is that everyone wants to treat it and people are grasping at straws," he said. Swash was not linked to the research and authored an accompanying commentary in Lancet Neurology.

He said specialized care and nutrition worked better than current drugs and could extend ALS patients' lives by a couple of years.

Scientists don't completely understand the cause of ALS, and Swash said more research is needed on how it evolves.

"The chance of finding a treatment without understanding the disease is very small," he said.

Another study

Britain's Motor Neurone Association is funding another lithium study. They insisted the drug might still be worthwhile.

"To stop our U.K. trial at this stage would throw away the real possibility that lithium might still have a significant benefit," Brian Dickie, the association's director of research development, said in a statement.

Aggarwal was unconvinced lithium might prove to have a major benefit on ALS, but said it was possible the drug could be combined with other therapies.

"We have to look for small gains with ALS," she said. "But at this point there is no reason for patients to take lithium."

The study was funded by the U.S. National Institute of Neurological Disorders and Stroke, the ALS Association and the ALS Society of Canada.