Is this Bipolar, ADHD, or pot effects? Please help.?

Okay, this has been a tricky question for the past seven months. My boyfriend of a year has been through hell.
Here's the past information:
He can't even remember exactly what year he started smoking pot because his memory is truly this bad. We estimated around 9th grade. He is now a senior. When he began smoking pot, it had all the normal effects- laughter, calming, and so on. But about a year and a half later (after smoking it every weekend of every week), the effects began to differentiate. He became paranoid, thought everyone was "messing with him," would call me yelling at me because he thought I was cheating on him at 2 am, while I was in my room sleeping. He became crazy. Slowly he realized this but still chased that good feeling. So he stopped doing it as much once he met me. The last happening of it was this past december, when he was in a room where people were smoking, he didn't, but the side effects still were brought on due to inhaling.
Now about June of last year, he realized he just wasn't feeling like himself.
Anxious, racing thoughts, depression, paranoia, lack of emotion.
He gets into these moods where he doesn't care about anything. His grades are low and getting to school is really hard for him. He has no motivation anymore.
He went to a psychiatrist and they diagnosed him with bipolar. She tried him on many different medications for bipolar and none seemed to work.
He then switched his psychiatrist who also diagnosed him with bipolar at the first visit. He was put on lamicital and risperidone. It had a small effect but he said he still doesn't feel normal or right.
Now this psychiatrist is saying that he may have ADHD, not bipolar. So they also added vyvanse to his medications. It seemed to work to help him concentrate, but only for four hours of the day. Then it stopped. And now it doesn't seem to be working much at all.
We are very confused.
Personally, I feel it was just his past drug usage. That it messed up the chemicals in his mind to give him these symptoms of bipolar and ADHD. Is this possible? Is there anyway to fix this? Such as medications? I know he has to stay away from it now, but do you think that this is the problem, or is it really bipolar or adhd, even if these medicines aren't being very effective. Have we just not found the right combination of medications?
Any answers would be appreciated.
Thanks ! :)

He hasn't smoked long enough for effects. And even if he had smoked for 20 years +, those aren't the effects of weed. It seems that he may have ADHD, and Laziness!! I am thinking the Shrink didn't prescribe him the correct meds because they probably didn't properly evaluate him as a subject. He should get a second opinion The Docs love to feed one problem with another drug. It sounds like your boyfriend is self medicating, pretty much masking his lack of enthusiasm for life with weed and eventually it will catch up to him, but paranoia is never that extreme and exaggerated. That just sounds like a minor case of Schizo. But what does anyone know, he could just be an irrational high anxiety type and all the wrong drugs the shrink is giving him may be screwing him up even more.

i would go to a different dr and get another opinion but give it time and if bi-polar meds were working some perhaps he needed an increase or something else i know myself it can take up to 2 months hope this helps

for one pot can't have that strong of side effects alone, but if he continually smokes pot while on medications then the effects can change dramatically and be severe, on another note you need to try other types of medications because some work for only certain people so try some others Abilify, Seroquil, Depakote just to try a few.

marijuana can create schizophrenia episodes. i suggest not smoking it.
(who wants schizophrenia) i say it's the marihuana.

If your boyfriend thinks there is any possibility that he was having any problems with ADHD or ADD, before, have him read the book called, "Allergies and the Hyperactive Child", by Dr. Doris Rapp. I know the title sounds like a book a high school student would not want to read, but he could look at it as 'research'. If he truly wants to figure this out, he needs to begin to learn. He should also understand the difference between ADHD and ADD. ADD is similar to ADHD but there is no problem with activity levels. The main problem is concentration and/or organization and memory. ADD can be very easily missed and the person can be labeled as lazy, when they are truly trying. This can be very frustrating. Please have him read the book so he can decide for himself what might be going on. Medications are fine where warranted. But information is very important to each one of us.