Lariam (mefloquine hydrochloride), a drug manufactured by Roche, used to prevent malaria; may cause suicide in some patients.

The drug has also been linked to other serious side effects, including suicide, hallucinations, paranoid delusions and severe depression. 

Malaria affects as many as 50 million people per year.  Lariam is taken by thousands of people traveling abroad, and by military personnel, as a preventive measure against malaria.  One of the reasons for its popularity is that it need only be taken once a week, instead of daily, like other anti-malaria drugs.

The drug maker, Roche Laboratories, acknowledges reports of suicide and suicidal thoughts and has begun to put warning labels on the drug. 

The World Health Organization estimates that as many as one out of every 20,000 people who take Lariam develop serious neuro-psychiatric effects. 

Many experts believe these numbers to be very low, and that the actual incidence of serious effects is closer to one out of every 6,000 people who take the drug.