ADHD Meds and Strange Behavior?

I was hoping to get some feedback from others about possible behavioral changes with ADHD stimulants. Ever since my husband started taking Vyvanse, his behavior is odd. In the morning he's groggy and out of it (more than usual or what is to be expected), but after he takes the meds he is calm and extremely focused and energetic. In the evening, he starts acting agitated, moody, almost paranoid, and...just strange. Up late, writing long letters that don't make sense, pacing, talking to himself, acting secretive and hostile towards me. I think it's the meds that are doing this. I asked him to stop and he refused (upped his dose, even). I'm really worried. Does this sound familiar?