Stimulant
Other stimulants work by binding to the receptors of excitatory neurotransmitters (e.g., nicotine) or by blocking the activity of endogenous agents that promote sleep (e.g., caffeine).
[2][3][4] Simulants have potential risks and side effects, such as addiction, tolerance, withdrawal, psychosis, anxiety, insomnia, cardiovascular problems, and neurotoxicity.
Stimulants can activate the same receptors as the natural chemicals released by the sympathetic nervous system (namely epinephrine and norepinephrine) and cause similar effects.
[7] Stimulants in therapeutic doses, such as those given to patients with attention deficit hyperactivity disorder (ADHD), increase ability to focus, vigor, sociability, libido and may elevate mood.
Acute toxicity has been reportedly associated with hyperhydrosis, panic attacks, severe anxiety, mydriasis, paranoia, aggressive behavior, excessive motor activity, psychosis, rhabdomyolysis, and punding.
[17] A review of a year long period of prescription stimulant use in those with ADHD found that cardiovascular side effects were limited to transient increases in blood pressure only.
[18] However, a 2024 systematic review of the evidence found that stimulants overall improve ADHD symptoms and broadband behavioral measures in children and adolescents, though they carry risks of side effects like appetite suppression and other adverse events.
Abuse of methamphetamine produces similar effects as well as marked degeneration of dopaminergic neurons, resulting in an increased risk for Parkinson's disease.
[39] Stimulants such as epinephrine,[40] theophylline and salbutamol[41] orally have been used to treat asthma, but inhaled adrenergic drugs are now preferred due to less systemic side effects.
[48] Although the efficacy for depression with continuous administration is modest, it may still reach statistical significance over placebo and provide benefits similar in magnitude to those of conventional antidepressants.
Many drugs in this class work primarily by activating trace amine-associated receptor 1 (TAAR1);[71] in turn, this causes reuptake inhibition and effluxion, or release, of dopamine, norepinephrine, and serotonin.
Physicians sometimes prescribe amphetamine to treat major depression, where subjects do not respond well to traditional SSRI medications,[citation needed] but evidence supporting this use is poor/mixed.
[48] Notably, two recent large phase III studies of lisdexamfetamine (a prodrug to amphetamine) as an adjunct to an SSRI or SNRI in the treatment of major depressive disorder showed no further benefit relative to placebo in effectiveness.
[73] Numerous studies have demonstrated the effectiveness of drugs such as Adderall (a mixture of salts of amphetamine and dextroamphetamine) in controlling symptoms associated with ADHD.
[77][78][79][80][81] Amphetamine is a potent central nervous system (CNS) stimulant of the phenethylamine class that is approved for the treatment of attention deficit hyperactivity disorder (ADHD) and narcolepsy.
[83][84][85][86] Although it is a prescription medication in many countries, unauthorized possession and distribution of amphetamine is often tightly controlled due to the significant health risks associated with uncontrolled or heavy use.
[82][94][95] Caffeine is a stimulant compound belonging to the xanthine class of chemicals naturally found in coffee, tea, and (to a lesser degree) cocoa or chocolate.
In the United States, the FDA has banned the sale of pure and highly concentrated caffeine products for personal consumption, due to the risk of overdose and death.
The herb má huáng (Ephedra sinica), used in traditional Chinese medicine (TCM), contains ephedrine and pseudoephedrine as its principal active constituents.
[124] Briefly used by some psychotherapists as an adjunct to therapy, the drug became popular recreationally and the DEA listed MDMA as a Schedule I controlled substance, prohibiting most medical studies and applications.
Products labeled as bath salts containing MDPV were previously sold as recreational drugs in gas stations and convenience stores in the United States, similar to the marketing for Spice and K2 as incense.
[135][136][137] Methamphetamine (contracted from N-methyl-alpha-methylphenethylamine) is a potent psychostimulant of the phenethylamine and amphetamine classes that is used to treat attention deficit hyperactivity disorder (ADHD) and obesity.
[142] Although rarely prescribed due to the potential risks, methamphetamine hydrochloride is approved by the United States Food and Drug Administration (USFDA) under the trade name Desoxyn.
[139] Also, the production, distribution, sale, and possession of methamphetamine is restricted or illegal in many other countries due to its placement in schedule II of the United Nations Convention on Psychotropic Substances treaty.
[148] Unlike amphetamine and cocaine, methamphetamine is neurotoxic to humans, damaging both dopamine and serotonin neurons in the central nervous system (CNS).
[155] Phenylpropanolamine (PPA; Accutrim; β-hydroxyamphetamine), also known as the stereoisomers norephedrine and norpseudoephedrine, is a psychoactive drug of the phenethylamine and amphetamine chemical classes that is used as a stimulant, decongestant, and anorectic agent.
In 1980, the World Health Organization (WHO) classified it as a drug of abuse that can produce mild to moderate psychological dependence (less than tobacco or alcohol),[165] although the WHO does not consider khat to be seriously addictive.
Common effects may include increased alertness, awareness, wakefulness, endurance, productivity, and motivation, arousal, locomotion, heart rate, and blood pressure, and a diminished desire for food and sleep.
Until the body reestablishes its normal state, once the effect of the ingested stimulant has worn off the user may feel depressed, lethargic, confused, and miserable.
[186] Research on a progressive ratio self-administration protocol has found amphetamine, methylphenidate, modafinil, cocaine, and nicotine to all have a higher break point than placebo that scales with dose indicating reinforcing effects.
