stimulantssubstances

Stimulant substances are a class of drugs that increase activity in the central nervous system, producing heightened alertness, energy, and attention. They differ from depressants by generally elevating mood and reducing fatigue, though effects can include anxiety, insomnia, and increased heart rate. Stimulants can be natural, prescription, or illicit. Natural examples include caffeine and nicotine. Prescription stimulants include amphetamine derivatives (dextroamphetamine, mixed amphetamine salts), methylphenidate, and wakefulness-promoting agents such as modafinil. Illicit stimulants include cocaine and methamphetamine.

Pharmacologically, most stimulants raise levels of monoamine neurotransmitters, especially dopamine and norepinephrine, in brain circuits involved in attention and reward. They may block reuptake, increase release, or both.

Applications vary: methylphenidate and amphetamines are commonly prescribed for attention-deficit/hyperactivity disorder and narcolepsy. Modafinil is used for excessive sleepiness. Cocaine and methamphetamine have no approved medical use in many countries and are controlled due to high abuse potential.

Effects include increased wakefulness and concentration, reduced appetite, heightened respiration and heart rate, and often euphoria or increased confidence. Adverse effects can include insomnia, anxiety, hypertension, cardiovascular events, dependence, and, with high doses or prolonged use, agitation or psychosis. Withdrawal can cause fatigue and dysphoria.

Regulation differs by country; caffeine is widely available, while many stimulants are controlled substances or require prescriptions. Harm reduction emphasizes avoiding excessive dosing, not mixing with alcohol or other depressants, seeking medical supervision for medical use, and recognizing signs of adverse effects.