depression
"I have taken 200mg Bupropion SR (100mg twice a day, eon/sandoz blue pill) for about a month for depression.  (Lethargy, fatigue, trouble with focus and memory). And it worked great, I had energy, feel focused and alert etc.  Only downside was that after 3 weeks I started having insomnia.  So at my 1 month followup, my doctor switched me to 150mg Bupropion XL (1 pill in the morning, global pharm yellow pill.)  I was fine the first morning on the new pill, but by 2pm I couldn't concentrate and by 6pm I was having headaches and anxiety (both symptoms I haven't had in the past.)  So I'll put in my vote for generics are different enough that you might do well on one and poorly on another."