A break in shared reality, the mind narrating a world the body alone can see.
Overview
Psychosis is a state, not a diagnosis. It describes a temporary or sustained loss of contact with consensus reality, and it can arise from many different underlying conditions. The hallmark features are hallucinations (perceiving what isn't there, voices being the most common), delusions (fixed false beliefs that resist contradicting evidence), and disorganized thought (speech and reasoning that derail, loosen, or fragment). What makes it disorienting is precisely that it feels certain from the inside; the break is invisible to the one experiencing it.
A State Across Many Conditions
Because psychosis is a state, it shows up wherever brain chemistry tips far enough. It is the defining feature of schizophrenia, a recurring component of schizoaffective disorder, and appears during the manic or depressive extremes of bipolar disorder. Severe major depression can carry psychotic features, and substances, stimulants, cannabis, alcohol withdrawal, hallucinogens, can trigger episodes directly. This is why "psychotic" describes what is happening, while the diagnosis describes why.
The Dopamine Hypothesis
The leading neurochemical account is the dopamine hypothesis: psychosis is associated with excess dopamine signaling, particularly in mesolimbic pathways, which over-tags ordinary perceptions and thoughts with significance and salience. The static of daily life becomes meaningful, threatening, or revelatory. The model is incomplete, glutamate and other systems matter too, but dopamine remains the practical target.
Treatment
Antipsychotics work by blocking or modulating dopamine (mainly D2 receptors). Older "typical" agents block forcefully; newer "atypical" ones modulate more selectively across dopamine and serotonin. They reliably dampen acute psychosis, and maintenance dosing holds it at bay.
A Continuum, Not a Switch
Psychosis sits on a continuum. Subtle forms: fleeting paranoia, a half-heard name, a too-perfect coincidence, are surprisingly common in the general population.
Related
- Schizoaffective Disorder, the condition where psychosis is one of two halves
- Dopamine, the neurotransmitter at the center of the hypothesis
- Dissociation, a related but distinct break in continuity of self
- Psychology: domain index