Stimulants are a class of drugs that act on the central nervous system, increasing alertness, energy, and attention while elevating mood. They achieve these effects by enhancing the activity of neurotransmitters such as dopamine and norepinephrine in the brain.

Many stimulant-related hazards are linked to intensive, high-dose, or long-term usage. The mode of administration plays a significant moderating role; injecting stimulants and smoking crack cocaine or methamphetamine have been specifically associated with more problematic use behaviours. Even people who use stimulants sporadically or...