## TL;DR

Addiction is a chronic brain disease characterized by compulsive substance use despite harmful consequences. It hijacks the brain's reward system (dopamine pathway). Addiction is not a moral failing — it has genetic (40-60% heritability), environmental, and neurobiological roots. Treatment: medication-assisted therapy, CBT, support groups.

## Core Explanation

Dopamine: the craving molecule — all addictive substances increase it. Tolerance: need more for same effect. Withdrawal: absence causes opposite of drug effect. Most addictive substances (ranking): heroin, cocaine, nicotine, alcohol, methamphetamine. MAT: methadone/buprenorphine for opioids. Harm reduction: needle exchanges, supervised injection sites. 'The opposite of addiction is connection' (Johann Hari).

## Further Reading

- [In the Realm of Hungry Ghosts (Gabor Maté)](https://drgabormate.com/book/in-the-realm-of-hungry-ghosts/)