The state commonly referred to as being “high” is the subjective experience resulting from the introduction of a psychoactive substance into the body. These substances are chemicals that cross the blood-brain barrier and temporarily affect the central nervous system. The term describes a temporary shift from an individual’s normal state of consciousness, impacting perception, mood, and cognitive processes. The drug initiates a biological response by interfering with the brain’s natural communication systems, causing this temporary neurochemical alteration.
Defining the Altered State
The experience of being high is fundamentally an altered state of consciousness. This psychoactive shift manifests as changes in emotional, sensory, and cognitive processing. Individuals often report euphoria, a powerful feeling of well-being, though the experience can also include dysphoria, anxiety, or paranoia, depending on the substance and dose.
Perception often changes, with some substances heightening visual, auditory, or tactile experiences, while others dull the senses. Cognitive and motor functions are temporarily impaired, affecting judgment, coordination, and reaction time. This chemical disruption results in a noticeable change in mood and behavior.
The Neurochemical Mechanism of Alteration
The mechanism behind this altered state originates in the brain’s communication network, where neurons transmit signals using chemical messengers known as neurotransmitters. Psychoactive substances exert their effects by temporarily interfering with this normal signaling process at the synapse, the tiny gap between neurons. Drugs can act as agonists, mimicking a natural neurotransmitter to activate the neuron, or as antagonists, blocking the receptor site to prevent signal transmission.
Many substances hijack the brain’s reward system, which is primarily regulated by dopamine. Drugs can cause neurons to release an unnaturally large surge of dopamine into the synapses, or they can prevent its normal reabsorption. This flooding of the reward circuit reinforces the drug-taking behavior and is the basis for the intense pleasure associated with many highs.
Why Experiences Differ Among Substances
The vast differences in subjective experience, such as the energized feeling from a stimulant versus the sedation from an opioid, are due to the specificity of each substance’s target in the brain. Different classes of psychoactive drugs affect distinct neurotransmitter systems, leading to unique psychological and physical effects.
Stimulants, like cocaine and amphetamines, primarily block the reuptake of dopamine and norepinephrine. This leads to a buildup of excitatory chemicals, causing heightened alertness, increased energy, and feelings of confidence.
Conversely, depressants, such as alcohol, primarily enhance the activity of Gamma-Aminobutyric Acid (GABA), the brain’s main inhibitory neurotransmitter. Increased GABA activity slows down neural signaling, resulting in a calming effect, muscle relaxation, and reduced anxiety.
Opioids mimic the body’s natural pain-relieving chemicals by binding to opioid receptors, which reduces pain perception and induces euphoria. Hallucinogens, including LSD, largely target the serotonin system, particularly the 5-HT2A receptors, radically altering sensory processing and thought patterns.
Factors Influencing Intensity and Duration
The intensity and duration of the high are governed by pharmacokinetics, the process of how the body handles the substance until its elimination. The dose consumed directly correlates with the concentration of the drug that reaches the brain, affecting the magnitude of the experience. The route of administration also determines the speed of onset; inhaling or injecting a substance reaches the central nervous system faster than oral ingestion, increasing the initial intensity.
The body’s metabolism, mainly carried out by liver enzymes, breaks down the psychoactive substance into inactive compounds. The drug’s half-life dictates the duration of the effects. Individual factors, such as body composition and genetic variations, also modify the experience. Furthermore, tolerance from repeated use requires a larger dose to achieve the same effect, altering the drug’s effective intensity over time.