This is addressed to elegantease in response to the above comment:
Pot addiction?! Are you sure it's an addiction. You know I've known people who have been addicted to meth and crack and heroin, but never pot.
Should this persons personal antecodotes determine your situation?
Are you sure now? Just because someone uses a drug (and you might not like it) doesn't mean it's an addiction. Addiction is a psychological illness and it takes a whole lot more than simply using a drug for someone to be addicted. My husband works with drug addicts as a former addict, and frankly someone taken it for pot addiction would be laughed at (because pot isn't considered an addictive drug, unless you listen to government propaganda.)
I don't think I addressed this in my intial comment above.
Cannabis-related disorders, including Abuse and Dependence, are listed in the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision, also known as DSM-IV-TR, a manual published by the American Psychiatric Association (APA) which includes all currently recognized mental health disorders.
But only you and a professional counselor can determine if your husband has a substance abuse problem. In the meanwhile, here is a quiz created by medical professionals, asking some sensitive questions to help you determine if your husbands marijuana use is becoming problem:
A study  published in The Lancet on 24 March 2007 was twenty drugs were assigned a risk from zero to three. Dr. David Nutt et al. asked medical, scientific and legal experts to rate 20 different drugs on nine parameters:
Physical harm (Acute, Chronic, and Intravenous harm)
Dependence (Intensity of pleasure, Psychological dependence, Physical dependence)
Social harms (Intoxication, Other social harms, Health-care costs)
Cannabis was ranked seventeenth of twenty for mean physical harm score and eleventh for mean dependence score. Not shown is the mean social harm score, which rated ninth, in a tie with Amphetamine.
1) ^ Nutt D, King LA, Saulsbury W, Blakemore C (2007). "Development of a rational scale to assess the harm of drugs of potential misuse". Lancet 369 (9566): 1047-53. doi:10.1016/S0140-6736(07)60464-4. PMID 17382831.
As cited in the article: Cannabis
Hey, don't get me wrong, I'm not trying to belittle the problem, but calling someone a pot addict only belittles real addiction problems. It just sounds like your husband is smoking pot because he's unhappy about something, as you are also, I'm guessing. check this out (http://www.ccguide.org.uk/psychological-dependence.php).
The above website they referred you to is a biased political advocacy website and bears no medical authority. Instead, for accurate information on any medical topic, I recommend independent professional medical sources, such as the American Psychological Association, American Medical Association, or WebMD. They may be onto something, though. Perhaps marriage counseling with a professional counselor may not be a bad idea.