Is smoking marijuana while studying lessens a student's ability to recall and to concentrate?

Sativa strains of marijuana can improve focus and concentration. It can be effective in the the treatment of ADD, ADHD would warrant a hybrid strain. Marijuana use only effects short term memory and this effect is only temporary, so it does not help you recall terms later on.

Also, remember that it is ILLEGAL -- if you want to get a job or stay out of trouble, stay away from it. It's not worth the slight increase!