"i went on the 300 xl version for about 1.5 years when i was in college. it improved my motivation/concentration/energy/mood, but i had hallucinations. also, i did have a few severe major depressive episodes while taking it but my rebound back to &quot;normal&quot; was quick. i stopped taking the medicine for about a year- turned into the most severe episode of depression. when i went back on it, started at 150mg sr - no problemw, then back on the 300 xl and had terrible anxiety/agitation. switched to 200sr- it&#039;s perfect. i&#039;m not as moody/mopey/feeling sorry for myself. i don&#039;t spend hours on the couch. the fog is gone but i think i will ask my doctor if i can take 2 x day- my fatigue/concentration are getting worse. overall, great medication."