Hi there!
Due to its anti-tumor, anti-inflammatory, neuroprotective, antimicrobial, and anti-depressant properties, CBC (cannabichromene) has garnered much interest from the cannabis and research communities. A 2010 pre-clinical study performed on mice, found that THC, CBD and CBC (but not CBN or CBG) reduced depression-related behavioral patterns.
https://www.ncbi.nlm.nih.gov/pubmed/20332000
Like Effexor, CBD and THC, CBC is also metabolized via the cytochrome p450 system. However, similar to CBD, there is no reason to believe that CBC is unsafe to take with Effexor.
https://www.ncbi.nlm.nih.gov/pubmed/1806943
For more info on CBC and other cannabinoids:
Beyond THC & CBD: What You Need to Know About CBC, CBN & CBG
Hope this helps!
drkim