Here is a great scientific report.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3286657/

The conclusion says it all –

Modafinil can be used by anyone, who wishes to work late, stay awake, enhance their cognitive reactions, or brighten their moods. Users may already be under a great level of stress, i.e. cancer patients or soldiers in a battle field. A psychoneuroimmunological approach is thus needed to investigate the multi-functional effects of modafinil.

Princeton

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