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[[File:Ritalin-SR-20mg-full.jpg|250px|thumb|right|[[Methylphenidate|Ritalin]] sustained-release (SR) 20 mg tablets.]] '''Stimulants''' (also known as '''psychostimulants''' and colloquially as '''"uppers"''') are a class of [[psychoactive substances]] that activate the nervous system to increase alertness, arousal, and motor activity.{{citation needed}} Stimulants represent one of the three major classes of psychoactive substances: the other two are [[depressants]] (also known as '''"downers"'''), and [[hallucinogens]]. Primary effects include [[wakefulness]], [[focus enhancement]], [[appetite suppression]], [[thought acceleration]], [[ego inflation]], and [[euphoria]].
'''Stimulants''' (also known as '''psychostimulants'''; colloquially as '''"uppers"''') are a major class of [[psychoactive substances]] that increase activity of the nervous system to promote alertness, arousal, and motor activity.<ref>{{cite book | vauthors=((Venable, S. J.)), ((Gilreath, J.)) | date= November 2012 | title=Drugs stimulating the central nervous system | pages=381–401}}</ref> Stimulants represent one of the three major classes of psychoactive substances alongside [[depressants]] ("downers") and [[hallucinogens]]. [[Subjective effects]] can vary but generally include [[wakefulness]], [[focus enhancement]], [[appetite suppression]], [[thought acceleration]], [[ego inflation]], and [[euphoria]].
Stimulants exert their effects through a number of pharmacological mechanisms, the most prominent of which are increasing concentrations of the [[neurotransmitters]] [[dopamine]] and [[norepinephrine]] by either promoting release (e.g. amphetamine, methamphetamine) or by blocking reuptake (e.g. cocaine, methylphenidate). Prominent examples of dopaminergic stimulants include [[amphetamine]], [[cocaine]], [[methylphenidate]], and [[methamphetamine]]. Some stimulants also have an additional significant effect on [[serotonin]], such as [[MDMA]], [[MDA]], and [[methylone]]. These substances are sometimes separately categorized and referred to as [[entactogens]].
Since being discovered in the early 20th century, stimulants have been adopted throughout some parts of the world as prescription medicines for attention deficit hyperactivity disorder (ADHD), narcolepsy, and obesity.{{citation needed}} They have also gained widespread illicit use as recreational substances, despite the efforts of various governments.{{citation needed}}
Since their discovery in the early 20th century, stimulants have been adopted throughout the world as prescription medicines for attention deficit hyperactivity disorder (ADHD), narcolepsy, and obesity and illicitly as recreational substances.
Stimulants produce their effects through a number of pharmacological mechanisms, the most prominent of which are increasing concentrations of the [[neurotransmitters]] [[dopamine]] and [[norepinephrine]] by either promoting release (e.g. [[amphetamine]], [[methamphetamine]]) or by blocking reuptake (e.g. [[cocaine]], [[methylphenidate]]). Some stimulants also have an additional significant effect on [[serotonin]], such as [[MDMA]], [[MDA]], and [[methylone]]; these substances are sometimes separately categorized and referred to as [[entactogens]].
In addition to intended therapeutic use, many stimulants have significant abuse potential. They can also induce tolerance, psychological dependence, and possibly physical dependence (although not by the same mechanism(s) as [[opioids]] or [[depressants]]). The toxicity of stimulants can vary widely based on the individual properties of each chemical. It is strongly advised to use [[harm reduction practices]] when using these substances.
==Chemistry==
==Chemistry==
{{chemistry}}
{{chemistry}}
Stimulants may be divided into different subgroups based on shared chemical and pharmacological features. Prominent groups include [[amphetamines]], [[phenidates]], and [[cathinones]].
==Pharmacology==
==Pharmacology==
{{pharmacology}}
{{pharmacology}}
Stimulants may be divided into different subgroups based on shared chemical and pharmacological features. Prominent groups include [[amphetamines]], [[phenidates]], and [[cathinones]].
Stimulants include substances with various mechanisms of action that generally, but not necessarily, increase catecholaminergic transmission in the brain. Stimulants that work by directly modulating catecholaminergic signalling act as [[Reuptake inhibitor|reuptake inhibitors]] (NDRIs, e.g. [[methylphenidate]]), [[Releasing agent|releasing agents]] (NDRAs, e.g. [[amphetamine]]) or receptor ligands (e.g yohimbine). Stimulants that work by indirectly enhancing catecholaminergic signalling include adenosine antagonists (e.g. [[caffeine]]) and [[nicotine]]. Stimulants that work independently of catecholaminergic transmission include ampakines and convulsants (e.g. strychnine).
==Subjective effects==
==Subjective effects==
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Alongside of these a variety of non-essential secondary effects are often present. These generally include but are not limited to:
Alongside of these a variety of non-essential secondary effects are often present. These generally include but are not limited to:
*'''[[Focus enhancement]]'''
*'''[[Focus enhancement]]'''
*'''[[Physical euphoria]]'''
*'''[[Physical euphoria]]'''
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*'''[[Increased music appreciation]]'''
*'''[[Increased music appreciation]]'''
*'''[[Ego inflation]]'''
*'''[[Ego inflation]]'''
*'''[[Time distortion]]''' - This can be described as the experience of time speeding up and passing much quicker than it usually would when sober.
*'''[[Pupil dilation]]'''
*'''[[Time distortion]]''' - This can be described as the experience of time speeding up and passing much quicker than it usually would when sober.
===After effects===
===After effects===
The effects which occur during the [[offset]] of a [[stimulant]] experience generally feel negative and uncomfortable in comparison to the effects which occurred during its [[peak]]. This is often referred to as a "comedown" and occurs because of [[neurotransmitter]] depletion. Its effects commonly include:
The effects which occur during the [[offset]] of a [[stimulant]] experience generally feel negative and uncomfortable in comparison to the effects which occurred during its [[peak]]. This is often referred to as a "comedown" and occurs because of [[neurotransmitter]] depletion. Its effects commonly include:
The compounds listed below have a varying degree of stimulant effects. Some of them have a minimal stimulant effect while others may have a strong one. Many of these substances possess other qualities including [[Entactogens|entactogenic]] or [[nootropic]] effects.
==Compounds==
The compounds listed below have been included on the basis of possessing varying degrees of stimulant effects. Some of them have a minimal stimulant effect while others may have a strong one. Many of these substances possess other qualities including [[Entactogens|entactogenic]] or [[nootropic]] effects.
Since being discovered in the early 20th century, stimulants have been adopted throughout some parts of the world as prescription medicines for attention deficit hyperactivity disorder (ADHD), narcolepsy, and obesity.[citation needed] They have also gained widespread illicit use as recreational substances, despite the efforts of various governments.[citation needed]
Stimulants produce their effects through a number of pharmacological mechanisms, the most prominent of which are increasing concentrations of the neurotransmittersdopamine and norepinephrine by either promoting release (e.g. amphetamine, methamphetamine) or by blocking reuptake (e.g. cocaine, methylphenidate). Some stimulants also have an additional significant effect on serotonin, such as MDMA, MDA, and methylone; these substances are sometimes separately categorized and referred to as entactogens.
In addition to intended therapeutic use, many stimulants have significant abuse potential. They can also induce tolerance, psychological dependence, and possibly physical dependence (although not by the same mechanism(s) as opioids or depressants). The toxicity of stimulants can vary widely based on the individual properties of each chemical. It is strongly advised to use harm reduction practices when using these substances.
Stimulants may be divided into different subgroups based on shared chemical and pharmacological features. Prominent groups include amphetamines, phenidates, and cathinones.
Stimulants include substances with various mechanisms of action that generally, but not necessarily, increase catecholaminergic transmission in the brain. Stimulants that work by directly modulating catecholaminergic signalling act as reuptake inhibitors (NDRIs, e.g. methylphenidate), releasing agents (NDRAs, e.g. amphetamine) or receptor ligands (e.g yohimbine). Stimulants that work by indirectly enhancing catecholaminergic signalling include adenosine antagonists (e.g. caffeine) and nicotine. Stimulants that work independently of catecholaminergic transmission include ampakines and convulsants (e.g. strychnine).
Subjective effects
Disclaimer: The effects listed below cite the Subjective Effect Index (SEI), an open research literature based on anecdotal user reports and the personal analyses of PsychonautWikicontributors. As a result, they should be viewed with a healthy degree of skepticism.
It is also worth noting that these effects will not necessarily occur in a predictable or reliable manner, although higher doses are more liable to induce the full spectrum of effects. Likewise, adverse effects become increasingly likely with higher doses and may include addiction, severe injury, or death ☠. These effects are listed and defined in detail within their own dedicated articles below:
Time distortion - This can be described as the experience of time speeding up and passing much quicker than it usually would when sober.
After effects
The effects which occur during the offset of a stimulant experience generally feel negative and uncomfortable in comparison to the effects which occurred during its peak. This is often referred to as a "comedown" and occurs because of neurotransmitter depletion. Its effects commonly include:
The compounds listed below have been included on the basis of possessing varying degrees of stimulant effects. Some of them have a minimal stimulant effect while others may have a strong one. Many of these substances possess other qualities including entactogenic or nootropic effects.
