Substance Abuse Disorder 

Substance Abuse Disorder is the new term for addiction. 

What are the neuronal mechanisms underlying addiction?

Addiction is Dopamine mediated. Every addictive drug modulates dopamine. Why? Dopamine is used by the Limbic system. 

Why is addiction closely connected to the Limbic system?

(a) The Limbic system helps us learn and (b) the Limbic system does the reward mechanism. It’s the confluence of these two things, learning and rewarding, that drives addiction. Drugs not only give us pleasure, but they teach us how to find it again. 

What about Serotonin? 

Serotonin is complicated. But for one, it makes us satisfied. It doesn’t affect Limbic-learning. Not very relevant to addiction. 

What happens to the brain when one stops taking the addictive drug?

Drugs provide Dopamine. Dopamine makes our Limbic system happy. We get a reward signal. Then the drug wears off, the Dopamine disappears. We’re left in a hypodopaminergic state. That causes cravings. Some of the neuronal changes that occurred are permanent :(

Which drugs are addictive?

Most drugs are addictive. Opioids, Alcohol, Stimulants (meth, coke), Depressants (benzos, sedatives), Nicotine. 

Which drugs are not addictive?

Pretty much just Cannabis, LSD and magic mushrooms (the serotonergic hallucinogens). Maybe Peyote and Ketamine too, but I’m not 100% sure of that.

Does therapy work for addiction?

Group therapy is a great start (AA). Psychotherapy works too. Relapse is expected, it happens like 70% of the time. 

Can we treat addiction with medications?

Yes, the best tx is with therapy plus medications. Read onward for a more detailed explanation...

VOCABULARY

Addiction – the neuro-psychological need for a substance, despite it causing you a lot of problems

Tolerance – after a while, your usual dose no longer gets the job done, and you have to increase it

Dependence - synonym for tolerance

Withdrawal – the unpleasant syndrome that follows quitting a drug that you are dependent on