The Science of Addiction & Healing Your Brain

What really separates a habit from a full-blown addiction?

In this powerful episode, Dr. Alex Tatem sits down with addiction medicine specialist Dr. Gretchen Johnson to unpack the science and humanity behind addiction. They dive deep into the difference between habits, dependency, and compulsive use — and how the brain changes during addiction and recovery.

From Adderall, caffeine, and alcohol to steroids and harm reduction, this episode explores the emotional, biological, and cultural sides of substance use that most people never talk about.

If you’ve ever asked yourself, “Is this a problem?” — this episode is for you.


0:00 – What is addiction? And how is it different from habits or dependency?
6:00 – Gretchen’s first experience with addiction patients that changed her career
9:15 – The beauty of recovery: Watching lives turn around completely
13:00 – Why addiction doctors must “practice what they preach” for their own mental health
16:00 – What daily care looks like in a full-scale addiction recovery center
20:00 – Why insurance companies, not doctors, often decide who gets treatment
24:00 – Understanding addiction as a chronic brain disease, not a moral failing
28:00 – Compulsive use explained: Why logic doesn’t work on addiction
33:00 – Dr. Tatem’s personal wake-up call with stimulant use
36:00 – “Addictive personalities” and why ADHD & trauma increase risk
45:57 – What harm reduction actually looks like (and why it works)
58:00 – The brain heals like a surgical wound — one layer at a time