I would say this study is inaccurate and shortsighted. I myself have smoked marijuana daily (5 to 6 times a day) for the past 15 years, and I have used it to help me stay motivated and achieve a succesful career in the IT business. Not only that I know many people like myself in my business who are daily smokers and who are equally if not more successful.

I'm not saying some folks who smoke do not have a lack of motivation, but the the lazy stoner is a stereotype and not reality. Millions of people are functional smoking, and use it to help them focus, alleviate stress, and cope with depression.

Prior to starting smoking when I was 22, I was depressed lacked motivation, and felt hopeless. Anti-depressants gave me serious gastrointenstinal problems, and did not provide the full effects marijuana did.

I recently quit marijuana because of my wife not liking the smell (perhaps the one downside), and have been off of it now for 2 months, and the feelings or depression, and lack of motivation are back.

BE CAREFUL WHEN MAKING BLANKET OBSERVATIONS LIKE THIS. Everyone wants to put people in a box, and there have been countless studies done over the centuries to reinforce racist and biggoted stereotypes which have been proven inaccurate. This study is along those same lines.