I think the authors say that the pain relief itself is only part of it:

> Lucas suggests the main reasons for the switch to cannabis from prescribed meds is due to reduced side effects, better symptom management and a feeling that cannabis is safer than prescription drugs.

Also, looking at http://www.webmd.com/pain-management/guide/understanding-pai..., it seems like chronic pain doesn't necessarily (?) mean severe pain, but maybe I'm wrong about that.