A British lawmaker has called for the UK army to prohibit the use of anti-malaria medication mefloquine for its soldiers over the drug contraindications that include psychosis, suicidal thoughts, depression and hallucinations.

Tory MP Johnny Mercer called for an immediate ban on the controversial drug (under the brand names Lariam, Mephaquin or Mefliam) given to British soldiers overseas.

Mercer told the state-run BBC that he had received many letters from service members claiming to have been affected by the once-a-week tablet which is linked with serious mental conditions.

“I’ve had a letter about once or twice a week from not only constituents, but people all over the UK who have suffered or know someone who has suffered, they believe, as a result of taking Lariam.”

“I just think we need to halt putting this drug out there for our guys and girls to use it until a proper study has been done, so that we know and more importantly our soldiers and their families know that this is a good defense against malaria and they can feel comfortable taking it,” the official said.

Lariam was developed by the US army in the 1970s, yet it was not until 1996 that the UK Committee on Safety of Medicines advised doctors to warn patients about the neuropsychiatric risks of taking the drug, according to the Guardian.

By 2014, the European Medicines Agency had warned of the “predominance of neuropsychiatric adverse reactions.”

The UK Ministry of Defense, however, said the use of Lariam was based on expert advice and pointed out that it was widely used by both civilians and the military.