If you have received a weekly medication to prevent Malaria from the CF since about 1992ish, it was most likely Melfloquine, otherwise known as Larium.
Most recently the dosage was 250mg starting 3 weeks prior to departure, until 4 weeks after return.
The dosing for this weekly medication has, over the last 20 yrs has decreased as it has been shown higher does are no more effective than lower doses to prevent malaria, while having a significant adverse effect rates.
It was seen at 1000mg (Somalia doses) that vivid dreams, nightmares, nausea, and occasionally seizures were an issue. Latest Kandahar dose of 250 mg per week still have a 1 in 10 occurrence of vivid dreams on the night of the dose, but that effect is mitigated by taking the medications earlier in the day.
BTW, the Mefloquine patient information card specifically states anyone who has suffered from depression, anxiety or schizophrenia should avoid the medications as the vivid dreams can aggravate the underlying condition. Anyone who claims that the medication "caused" them to have a mental illness after taking it, should be very careful to not have any mental health issues prior to taking the drug.
I have an electronic version of the patient info cards for Mefloquine and Malarone on my computer. If people want to see them, I can attach them.
BTW; 3 tours of Afghanistan, seen lots of blood and badness. Took Mefloquine all three times. Had dreams. Had nausea. All went away once drug was discontinued after I was home....every time.
My position: every medication has its role, and adverse effects. As a medical professional, we constantly balance the drugs affects with its effects. Mefloquine remains the most reliable drug for long term use in a hot, sunny climate. The US Army tended to dose their soldiers higher than the CF, which may explain some of the issues. In the last year, the US forces have switched to Doxycycline (an antibiotic) as their primary malaria prophylaxis medication. My take is they did it because of the cost. Malarone is a very expensive drug, at about $4 per tab vs 50 cents for Doxy.