Does Marijuana affect serotonin in the brain?

Question

I was on antidepressants for sometime and found that when I smoked while on meds, I'd have really bad trips. I went off meds for a while and continued to smoke and stopped having the crazy "freakouts."

How does THC affect serotonin and is there a link between the meds, weed and bad trips or was it all in my head?

Answer 1

There must be some confusion about anandamide. Delta-9-THC (thought to be the active component in marijuana) mimics chemicals in the brain that bind to the "cannabinoid receptors".  We decided to search for chemicals that naturally occurred in the brain and found a few, anandamide being one of them.  Anandamide plays a part in metabolism (not neurotransmitter metabolism), pain, cognitive functions...

THC is metabolized by hepatic mitochondrial enzymes similar to those used to metabolize some antidepressants (see first source publication for amitriptyline).  The combo has been known to cause tachycardia (fast heartbeat), mood changes, (and with all antidepressants) hallucinations, mood swings, confusion, mania, and depression. Marijuana alone when case studied has also been linked to depression.  

Another problem with Marijuana is it's not just delta-9-thc we need to focus on, weed brings with it 65 other cannaboids into our system! While not the main components in the high, they are possibly the problem in adverse effects when taken with anti-depressants.

Please read the last article listed, there are different types of anti-depressants and all are effected by weed in different ways. SSRIs and lithium are deemed OK with marijuana, while MAOIs are pronounced not effective when combined with marijuana. As stated earlier tricyclic antidepressants are very dangerous when taken with marijuana due to tachycardia. Hope this helps.

Answer 2

Yup. THC emulates the natural neurotransmitter anandamide. This chemical is implicated in controlling the metabolism of virtually every neurotransmitter in the brain - especially the monoamines (Serotonin, Norepi, Dopamine).

Antidepressants and marijuana do NOT play nice together. Typically what happens is that marijuana reduces the effectiveness of the antidepressants by mucking with brain metabolism. But yes this does happen. Making antidepressants not work is virtually guaranteed, but inducing bad reactions to pot is common enough to be fairly well documented.