"when i was taking this just as a smoking cessation aid, i couldn&#039;t sleep ever. not even when i took half the prescribed dose and took it early in the morning. it made me crash, made me irritable and couldn&#039;t eat. but now i take it for major depressive disorder and as smoking cessation, and even on 2 tablets (300mg total) i fall asleep! and not at night time...it makes me fall asleep during the day, especially after it kicks in. i can take it at 5pm and fall asleep at midnight or even before, take naps, etc. this is the only antidepressant i will take, because ssri&#039;s do not work one bit for me. they make me feel more depressed. wellbutrin does help my moods though. i don&#039;t get fits of rage when i take this anymore like i used too."