Stimulants are a class of drugs that increase activity in the brain and nervous system, making people feel more alert, energetic, focused, and awake.

What they’re used for
• Medical uses:
• Treat ADHD (improves focus and impulse control)
• Treat narcolepsy (excessive daytime sleepiness)
• Non-medical use:
• Boost energy, confidence, or performance (high risk when misused)

How they work

Stimulants increase levels of brain chemicals like dopamine and norepinephrine. This:
• Speeds up brain signaling
• Increases heart rate and blood pressure
• Reduces fatigue and appetite
• Enhances alertness and concentration

Common examples
• Prescription stimulants:
• Amphetamine (Adderall)
• Methylphenidate (Ritalin, Concerta)
• Illegal stimulants:
• Cocaine
• Methamphetamine
• Legal stimulants:
• Caffeine
• Nicotine

Effects

Short-term effects
• Increased energy and focus
• Elevated mood or euphoria
• Faster heartbeat
• Reduced appetite
• Restlessness or anxiety

High-dose or long-term risks
• Addiction and dependence
• Insomnia and extreme anxiety
• Heart problems (arrhythmia, high blood pressure)
• Paranoia or hallucinations
• Weight loss and malnutrition

Crash & withdrawal

After the effects wear off, users may feel:
• Extreme fatigue
• Depression or low mood
• Irritability
• Strong cravings

Safety notes
• Misusing stimulants can seriously damage the heart and brain
• Mixing stimulants with alcohol or other drugs increases overdose risk
• Prescription stimulants should only be used under medical supervision