[da_chicken]

No, they make pills that are 150 mg. I was on 300 mg of daily Welbutrin XL for several years, though more often I was on 150 mg. I also took about 20 mg of Prozac, which seemed to have a smoothing effect. My only side effects on the stronger dosages was an acid stomach, and I could mitigate that by eating half a bagel or muffin in the morning.

I remember asking my psychiatrist about the dosage because it seemed high to me. He told me that up to 450 mg was the recommended maximum, and that he did have a few patients who had been on stronger doses. I believe he said he knew of one patient on 750 mg, though he may have said 600 mg.

Just based on my personal experience, psychiatric drugs are highly variable. I did very well under Welbutrin, while even the smallest dosages of Effexor had me waking up with constant nightmares and a non-euphoric, altogether unpleasant "buzzed" feeling not unlike a hangover without the headache. I also know people who swear by Effexor.

Edit: Today I almost entirely mitigate my depression with natural light therapy.