Does marijuana produce serotonin?

My girlfriend tells me she uses marijuana to calm herself if she is having a stressful day. She has been doing this for many years. She says smoking pot is like self-medicating — it is better than using anti-depressants. She also claims smoking pot helps with depression because of how it helps produce serotonin in the body. What is serotonin and how does it help depression? Does smoking pot really help with managing your anxiety, depression, etc.?


How long should I wait to use Viagra after using poppers?

I know that it is extremely dangerous to mix viagra (or other ED drugs) and poppers (amyl nitrate), and that one should wait for 24 hours after using viagra (to let it get out of your system) before using poppers. My question is what is the waiting period after using poppers before it is safe to use viagra? In other words, how long before the physiological effects of poppers wear off?