Modafinil is often given to patients as part of a regimen with other medicines. Many doctors give it to patients taking antidepressants. Although modafinil is not approved for depression or anxiety disorder by the FDA, in practice it is often used for these conditions.
A report published in the Journal of the American Medical Association showed that 45 percent of modafinil patients were also taking an antidepressant, 15 percent were taking a benzodiazepine medicine, and 6 percent were taking a prescription amphetamine.
Drugs that affect change the mental state include those that act on the noradrenaline, acetylcholine, glutamate, histamine, cholinergic, and melatonin systems as well as glucocorticoids, and immune-modulating agents. There is little scientific work on how a patient might do when taking those drugs with modafinil. Doctors in the field are trying different things.
Some still worry about widespread use of modafinil. Cocaine and amphetamines were once enthusiastically embraced by the medical field and employed to combat depression and to make people work harder, much as modafinil is today. Will we someday regard modafinil the way we regard cocaine and amphetamines?
There is no reason to think that modafinil will increase the sex drive nor much empirical evidence that it does so. It has anti-depressant effects and increases dopamine levels in part of the brain so people may feel their sex drive is somewhat higher under its influence, but no more so that for other psychoactive drugs and antidepressants.
The armed forces in the US and in other countries were among the first to try modafinil on a large scale. Stimulants have been used to help soldiers for decades, if not centuries. While the status of modafinil in military circles is not public, observers suspect it is still part of the list of potential medicines given to soldiers. Article on use by military aviators.