Psychosis changes how a person perceives reality. It can involve hearing or seeing things that aren’t there, holding beliefs that don’t match the evidence, speaking in ways that are hard to follow, or losing motivation and emotional expression almost entirely. About 0.3% of the global population experiences schizophrenia alone, and psychosis itself appears across many conditions, from severe depression to substance use to medical illness. What makes psychosis difficult to recognize is that it rarely looks like the dramatic portrayals in movies. More often, it builds gradually, and the person experiencing it may not realize anything has changed.
Hallucinations: Sensing Things Others Can’t
Hallucinations are false perceptions that feel completely real. They can affect any sense: sight, sound, smell, touch, or taste. Hearing voices is the most common type in people with psychotic disorders. These voices might comment on what the person is doing, argue with each other, or issue commands. They can be neutral, encouraging, or hostile. Some people hear footsteps, music, or doors slamming instead of speech.
Visual hallucinations are also possible. People commonly see moving patterns, shapes, vivid faces, animals, or full scenes. Others experience tactile hallucinations like the feeling of insects crawling on their skin, or smell odors no one else can detect. What matters is that these experiences are involuntary and feel indistinguishable from real sensory input. A person having a hallucination isn’t imagining something on purpose. Their brain is generating a perception as convincing as anything coming through their actual senses.
Delusions: Beliefs That Won’t Budge
Delusions are fixed beliefs that persist even when there’s clear evidence against them. They come in several patterns. Persecutory delusions are the most common: the person believes they’re being followed, spied on, poisoned, or conspired against. Grandiose delusions involve believing you have special powers, a secret identity, or a personal relationship with a famous or powerful figure. Somatic delusions center on the body, such as the conviction that you have a serious disease or that something is physically wrong despite normal medical tests.
From the outside, delusions can look like stubbornness or conspiracy thinking, which is part of why they’re easy to miss early on. The key difference is rigidity. A person with a delusion isn’t just skeptical or misinformed. They cannot update the belief when confronted with contradictory evidence, no matter how persuasive. Trying to argue someone out of a delusion typically doesn’t work and can damage trust.
Disorganized Thinking and Speech
Psychosis often disrupts the ability to organize thoughts into a logical sequence. You might notice this in how someone speaks: they jump between unrelated topics mid-sentence, give answers that don’t match the question, or string words together in ways that sound like they should make sense but don’t. Sometimes the connections between ideas are so loose that conversation becomes nearly impossible to follow.
This isn’t the same as being distracted or scatterbrained. The person’s internal logic has genuinely fractured. They may not realize their speech sounds incoherent to others, because to them, the connections between ideas feel natural.
Disorganized and Unusual Motor Behavior
Some people in psychosis display physical behavior that seems unpredictable or out of context. This ranges from restless pacing and agitation with no obvious trigger to exaggerated, theatrical movements that mimic normal gestures but look “off.” In more severe cases, a person might mimic the movements or speech of people around them, or act aggressively without any situation prompting it.
At the other extreme is catatonia, where a person becomes physically unresponsive. They may hold a rigid posture for hours, resist any attempt to move their limbs, or stop speaking entirely. Some people in a catatonic state have a waxy quality to their muscles, where a limb can be gently repositioned and will stay in whatever position it’s placed in before slowly drifting back. Catatonia can also swing the other direction into constant, purposeless movement. Both ends of this spectrum are medical emergencies.
Negative Symptoms: What Disappears
The symptoms above involve something being added to a person’s experience: voices, beliefs, unusual behavior. But psychosis also takes things away, and these “negative” symptoms are often the hardest to recognize because they look like depression, laziness, or withdrawal. The word “negative” here doesn’t mean bad. It means a loss or reduction of normal function.
Reduced emotional expression is one of the most visible. A person’s face may become flat, showing little reaction to good or bad news. Their voice loses its normal rise and fall. They make less eye contact. Alogia, or poverty of speech, means the person talks less, uses fewer words, and may only respond when directly spoken to rather than initiating conversation. Avolition is a deep loss of motivation: not just feeling unmotivated, but being unable to start or sustain basic activities like showering, cooking, or leaving the house. These symptoms tend to be more persistent and harder to treat than hallucinations or delusions, and they take a significant toll on relationships and daily functioning.
Early Warning Signs Before a Full Episode
Psychosis rarely arrives overnight. Most people go through a prodromal phase, a period of weeks or months where subtle changes accumulate before a full psychotic episode develops. Recognizing these early signs is one of the most valuable things a family member or friend can do.
Early changes in thinking might include feeling suspicious that others are trying to cause harm, believing that everyday events hold special personal meaning (a song on the radio was meant specifically for them, a stranger’s glance was a signal), or sensing that others can read their thoughts. Some people feel confused about whether an experience was real or imagined. They might describe their thoughts as being so loud that other people should be able to hear them.
Behavioral changes are often easier to spot from the outside. The person may withdraw from friends and activities they used to enjoy, spend much more time alone, struggle with concentration or memory at school or work, let personal hygiene decline, or have trouble organizing their speech. Mood shifts are common too: new or worsening anxiety, depression, irritability, or dramatic swings in energy and emotion. No single sign confirms anything, but a cluster of these changes, especially in a teenager or young adult, warrants attention.
What Causes Psychosis
Psychosis is not a single disease. It’s a set of symptoms that can arise from many different sources. Schizophrenia is the condition most associated with psychosis, but severe depression, bipolar disorder, extreme sleep deprivation, and postpartum hormonal shifts can all trigger psychotic episodes.
A number of medical conditions are known to cause psychosis as well, including Alzheimer’s disease, Parkinson’s disease, brain tumors, HIV, lupus, multiple sclerosis, dangerously low blood sugar, high fevers, and head injuries. Substance use is another major trigger. Cocaine, methamphetamine, amphetamines, MDMA, cannabis, LSD, psilocybin mushrooms, and ketamine can all provoke psychotic episodes. So can alcohol, particularly during withdrawal after heavy, prolonged use. In rare cases, certain prescription medications can cause psychosis as a side effect or in overdose.
At a biological level, psychosis involves disrupted signaling in the brain’s dopamine system. Dopamine normally helps the brain tag which stimuli in the environment are important and worth paying attention to. In psychosis, this signaling becomes erratic: irrelevant sights, sounds, or thoughts get flagged as deeply meaningful. This helps explain why a person in psychosis might interpret a passing car or a television broadcast as a personal message. Research published in Trends in Neurosciences suggests that dopamine dysfunction in brain regions involved in habit formation may also contribute to the rigid, unshakeable quality of delusional thinking.
What to Do If You See These Signs in Someone
If someone you know is showing signs of psychosis, the most important thing is to stay calm and avoid arguing with their perceptions. Telling someone their hallucinations aren’t real or their beliefs are wrong is unlikely to help and can feel threatening to them. Instead, focus on their emotions: “That sounds really frightening” is more useful than “That’s not happening.”
Take any mention of self-harm or harm to others seriously. If the person seems at risk of hurting themselves or someone else, they need to be evaluated by a medical or mental health professional immediately. If their behavior escalates to the point where you feel unsafe, remove yourself from the situation and call emergency services. Outside of a crisis, know that a person experiencing psychosis generally cannot be forced into treatment unless they meet specific legal criteria for involuntary commitment, which vary by location. Gentle, persistent encouragement toward professional help is typically the most effective approach.