![](https://cannabis.net/drive/1000/3743_KvV6_smokingweedeveryday30years.jpg?width=200&height=200)
According to Aaron Weiner, a cognitive behavioral therapist and addiction counselor in Lake Forest, Illinois, the severity of long-term marijuana usage is greatly influenced by the age of the user and the potency of the marijuana being consumed. The effects of marijuana use are worse the younger a person is when they first start using it and the stronger the THC concentration.