First of all, TeenHealthFX would like to applaud you on your decision to stop using marijuana. Besides the fact that it is still considered an illicit drug, the scariest thing about it is that you can never be sure that it is not laced with other substances to either increase its addictive potential or increase the weight of the drug sold. There have been documented reports of marijuana laced with crack cocaine, PCP, formaldehyde, heroine, and even lead flakes. Though this might not seem like a big deal at the time, many of these substances can destroy your life with just one use. The truth is that drug dealers care about the bottom line – money – and could care less about what happens to your life or how they ruin your future.
As for your specific question, the only behavioral ramification of using marijuana is that it does cause "amotivational syndrome.” Basically users feel that they have no motivation to do anything from playing sports, studying, keeping appointments, and yes, even sex. Secondly, marijuana not only causes a decrease in testosterone production, but it also lowers your prolactin, thyroid hormone, and growth hormone levels. In males, this can lead to decreased sexual desire, erectile dysfunction, shrunken testicles, and even gynecomastia (the infamous “man-boobs”). There have also been reports of decreased sperm counts and decreased sperm motility. Most of the medical articles that document these findings have been based off of marijuana use over multiple years. There is little data to say whether the effects are reversible after stopping the drug. You should also be aware that many men have used marijuana in their youth and that they managed to father children, have erections, etc., but there has been a steady increase in the potency of THC (the active drug in marijuana). In fact the average amount of THC in marijuana has quadrupled in the past 20 years, so today’s marijuana users are writing the book on adverse effects of marijuana as we speak.
Fortunately for you, it sounds that you have only been using for a little while, so any adverse effects of marijuana use should subside. Unfortunately, there have been few studies done to follow long term effects of THC in otherwise healthy males. The fact that you are still having morning erections is a good sign. It means that the hormone pathway from your brain to your testicles is still intact. Teenage erectile dysfunction is usually more of a psychological problem than an actual physical one (especially since you are having morning erections). Sometimes just worrying about not having erections can lead to difficulty having erections or failure to orgasm. FX encourages you to be patient with yourself, as less worry will enable better outcomes for you! Exercise has also shown to be effective in regulating sex drive. It is very possible that the last thing you wanted to do after smoking was to go work out. Maybe increasing your physical activity will be a healthy alternative, a stress reducer, and a good social scene for you instead of smoking. It sounds like you have already started to take control of the situation by stopping your marijuana use!
One final thought: Remember there are other reasons for erectile dysfunction (diabetes, chronic alcohol use, vascular problems) so if you continue to have difficult erections or absence of morning erections, it would be a good idea to go to your doctor because it could be a sign of something more serious. If you don't have a doctor and live in northern New Jersey, you can call the Adolescent/Young Adult Center for Health at 973-971-6475 for an appointment or contact your local teen health center. You can also contact your insurance company for a list of in-network providers.