Addiction= disease. Smoking weed may be harmful in a number of ways. It is neither bad nor dumb. Mutual support may be useful. Consider marijuana anonymous.
Bad. It impairs judgement as much alcohol does and is responsible for many traffic accidents. Long term use may damage the airways, lungs and brain.
Weed side effects. "smoked marijuana damages the brain, heart, lungs, and immune system. It impairs learning and interferes with memory, perception, and judgment. Smoked marijuana contains cancer-causing compounds and has been implicated in a high percentage of automobile crashes and workplace accidents.".