Information travels through the brain as electrical signals along a complex network of interconnecting nerve cells called neurons.

Neurons connect to each other at synapses, small gaps where chemicals called neurotransmitters amplify or muffle the electrical signals.

The reward pathway determines our experience of pleasure and many psychoactive drugs work by over-stimulating this pathway.

After using psychoactive drugs, the brain needs time to recover. This is often experienced as a psychological ‘crash’ or ‘come down’.

If a drug is used regularly, the desired effects become harder to achieve – a process called tolerance.

People who use drugs often increase the amount of drug they take over time in an attempt to overcome tolerance. This increases the risk of drug-related harm.

Regular psychoactive drug user ends up altering brain functioning, making it much harder to enjoy non-drug experiences. The world can become joyless.