I believe it lowers motivation. I didn't try pot until I was 17 because I had no desire. I had a passion for music so i never cared for it, despite the fact I had been around it for years. But I'm 19 and I've been smoking for 2 years, I feel like I'm less motivated than I was to make music. I still do it, all the time... but unfortunately I rarely do it sober. I'm always smoking in the studio.