Been a drug addict for over 30 years is your brain fried?

Answer 1

That depends on what drugs you've been taking, how much, and how often. Some drugs don't cause any permanent brain damage.

Brain Damage with Every Use:

Amphetamine and Methamphetamine (speed)

PCP

MDMA / Ecstasy (maybe)

Brain Damage with Excessive Use:

Alcohol

Cocaine

Benzodiazapines (maybe)

SSRI Antidepressants

Antipsychotics / Major Tranquilizers

Drugs that Don't Cause Brain Damage:

Cannabis

Serotonergic Hallucinogens (LSD, Mushrooms, Peyote, etc..)

Opiates (Heroin, Oxys, Vicodin, etc..)

Methamphetamine is probably the worst of these, followed by PCP. Alcohol causes a lot of damage if abused.

Even drugs that don't cause brain damage will sometimes cause changes in the brain if they are over-used. The brain tries to adjust to the presence of the drug, and when you stop you go into withdrawal. This sort of change reverses over time.

The Hallucinogens are a special case. They don't cause brain damage, even in very high doses, but in a small percentage of users (less than 1%) they cause permanent changes in vision. These changes typically happen after the first use and can last for years.