no, but not due to that. cannot say in your particular case but in general effects of marijuana are not often terrible. 1) legal issues and risks of jail and bad record 2) marijuana is a slight stimulant, there will be slight increased strain on the heart but if you walk up 2 flights of stairs or run 5 blocks.... it s about that much...so.....not more strain than people have . daily. 3) this is the bad one. It is associated with a permanent problem in brain development if used below 18 years of age and generally lowers intelligence by a significant amount. It s a fairly new finding, but it has held up over several studies. It also fits with observations. There is not an obvious brain damage like holes eaten in the brain. Possibly some degree of difficulty in trying one s hardest on the intelligence test occurs but this does correlate with job/professional/acheivement problems. Course it could also be hanging around with friends who de-motivate and lower expectations and lower desires for further personal development and not the marijuana.