Your Brain Crack and Heroin

How Crack and Heroin affect your brain

How Crack and Heroin affect your brain

Brain Chemistry

The brain works by releasing a sort of ‘chemical e-mail’ to communicate between its billions of cells. These chemicals are called neurotransmitters and play an important role in mental illness.

Heroin is a pain killer (it reduces both pyhsical and emotional pain). It does this by boosting the level of neurotransmitters called endorphins - the body’s natural pain killers. Endorphines are released naturally when you excercise, they act on pain and probably also modulate mood. The release of endorphins can make you feel euphoric.

The stimulant effect of cocaine (crack is just smokable cocaine) is caused by the release of a neurotransmitter called noradrenaline. Like most other illegal drugs heroin and cocaine both cause the release of a neurotransmitter called dopamine.


Dopamine is the brain’s main reward or pleasure chemical. The release of dopamine is one reason why drugs feel pleasurable.

Heroin almost doubles the level of dopamine in your brain, while smoking or injecting crack increase it to four times normal levels. Injecting both drugs at the same time (known as a ‘speedball’) increases the levels of dopamine to ten times normal levels.

Repeating this intense feeling of pleasure is what drives speedballers to continue using, until avoiding the comedown, habit and addiction take over as the main reasons for use.

Although we don’t know everything about the relationship of dopamine to mental illness, we do know drugs used to treat schizophrenia type illnesses seem to work by reducing the levels of dopamine in the brain.

Progress - National Consortium of Consultant Nurses in Dual Diagnosis & Substance Use