Types of drug

A drug is a substance taken into the body that modifies or affects chemical reactions in the body. Some drugs are beneficial, while others are harmful.

Type of drugEffect on bodyExample
DepressantSlows down nerve and brain activityAlcohol, solvents, temazepam
HallucinogenAlters what we see and hearLSD
PainkillerBlocks nerve impulsesAspirin, paracetamol
Performance enhancerImproves muscle developmentAnabolic steroids
StimulantIncreases nerve and brain activityNicotine, caffeine, ecstasy

Stimulants and depressants affect the synapses between neurones in the nervous system:

  • stimulants cause more neurotransmitter molecules to diffuse across the synapse
  • depressants stop the next neurone sending nerve impulses. They bind to the receptor molecules the next neurone that needs to respond to the neurotransmitter molecules.

Classification of drugs

Some drugs are illegal, or must only be prescribed by a doctor. Some prescription drugs are misused and taken for recreational use, rather than for medical reasons. They become illegal under these circumstances.

White pills

Illegal drugs are classified from Class A to Class C. Class A drugs are the most dangerous, with the most serious penalties for possession or dealing. Class C are the least dangerous, with the lightest penalties, but this does not mean they are safe to use.