Expert: Peter L. - 9/2/2010

Question
What are the most serious long term effects of smoking marijuana on a daily basis?

Answer
Hi Clara,

The effects of marijuana, particularly long term, just happens to be an area of particular interest to me.  Thanks for such an important question.

Marijuana is a drug that has remained constant in terms of use in our culture, while others have flucturated.  We've seen an alarming increase in opioid use in the last decade, where this appeared to be a problem limited to cities long ago.  Cocaine use has fluctuated, and perhaps is in a bit of a decline, and alcohol use has been constant, and actually increasing.

Nowhere do you hear the term "maintenance" applied to any drugs except marijuana and methadone.  Methadone is, of course, a drug used to treat opioid dependence (heroin or prescription meds) and often is taken for long periods of time.  Hence the term methadone maintenance.

On the other hand, you hear of the "marijuana maintenance" plan, which is simply a way to have a substance use experience that seems to be safer than harder drugs.

Lots of people smoke marijuana everyday, and quite a bit of it, and  keep relative normalcy in their lives.  That's one reason it appears to be essentially harmless.  

I believe there are consequences associated with the long-term use of it, however.  I find long-term users kind of "flat", basically functioning but lacking aspirations, drive, or a desire to rise above mediocrity.  They just seem kind of blase to me, not particularly motivated people.  Some clients I work with have so much weed in them their brains seem almost numbed out.  They have no spark whatsoever.  

Some researchers believe the steady accumulation of THC in the brain impairs its optimal functioning, but I don't get a sense they believe it is permanent.  But I think the longer you smoke heavily, the more it seems you have incurred permanent damage.

No doubt the lungs are not happy about the constant infusion of marijuana smoke, as it's heavily laced with tars.  

I also think smoking marijuana affects your metabolism, encouraging you to eat the wrong things (munchies).  There is some evidence it has a negative effect on the immune system.  

But having said all that, most smokers will not experience the degree of financial, familial, legal, medical, employment, relationship consequences associated with drugs like alcohol, cocaine, opioids, or methamphetamine.  As such, it's reputation is kind of "sanitized" in the popular culture, and as such its use remains steady, even going up.  And there are those who advocate for making it legal.

Hope this answers your question,
Peter