Hey, I take the meds exactly as prescribed by my physician which is also in the evening. certainly not misuse.
I also study in university and often study in the evenings. and when I say evening I mean afternoon, not in the night.
its not really related to sleep, I usually sleep well and at leat 7-8 hours every night. I have a theory it might be due to some imbalance between Dopamine and Norepinephrine at times. My doctor didn’t really know what could cause the variations in effectiveness from day to day. thanks for sharing your experiences also.