If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

Main content


Visit us (http://www.khanacademy.org/science/healthcare-and-medicine) for health and medicine content or (http://www.khanacademy.org/test-prep/mcat) for MCAT related content. These videos do not provide medical advice and are for informational purposes only. The videos are not intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of a qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read or seen in any Khan Academy video. Created by Tanner Marshall.

Want to join the conversation?

Video transcript

- [Voiceover] When someone has psychosis, they have some kind of disturbance in their sense of reality, which could be having some kind of beliefs that simply aren't true, or it could be seeing or hearing things that aren't there, and they're unable to tell the difference between what's real and what's not real. When they have these false beliefs, they often feel very strongly about them, and will not change their mind, even if there's a lot of evidence against it. These thoughts are also known as delusions, and these delusions are usually compared to other people of the same culture, and that last bit's really important because what's considered unusual in one culture might be a completely normal belief in another. So, there are several different types of delusional thinking to distinguish between. The first type is delusions of reference, which is believing that certain events aren't random or neutral, but instead, something that's aimed at the person. So an example of this could be like if somebody thought that some article in the newspaper was written for them, that the writer was trying to send them a personal message of some kind. And this would be considered a delusion of reference. Another type of delusion, though, is a grandiose delusion, or maybe more commonly heard as delusions of grandeur. These are based around the person believing that they have some sort of unique significance or power. For example, believing that they're actually a ruling king or queen that deserves to be treated like royalty. Now a third type is paranoid delusions, and these are based around paranoia, and the belief that they're being harmed or watched by someone or some group of people. For example, thinking that the van parked outside the house is actually filled with people trying to spy on them. And this type is of particular concern, because it can sometimes lead to patients not taking their medications or treatments due to paranoid beliefs about the treatment. Now there also could be delusions of control, which is believing that another person or group or force controls their thoughts, feelings or actions. So this could be like thinking that aliens are controlling the way they think or their actions. And finally, there's erotomanic, where they incorrectly believe that someone else, usually a stranger, or maybe someone famous or of high-status is in love with them. So, for example, thinking that a famous singer is actually in love with them, and this one's of also particular importance because it can sometimes lead to legal issues like restraining orders because the so-called relationship is one-sided. Now sometimes a further way to categorize these delusions is by their apparent plausibility or how reasonable they are. We'll either say they're bizarre or non-bizarre, and non-bizarre delusions are those that are technically within the realm of possibility, so they could be true, technically, but they're usually pretty exaggerated, like the example of the singer being in love with them. But bizarre delusions are those that are clearly implausible and really not taken from any sort of ordinary life experiences, so like the delusion of control where the aliens were controlling their actions and their thoughts. That would be considered a bizarre delusion. So those were all delusions, which had to do with the thoughts and beliefs people had, but people diagnosed with psychosis may also have hallucinations, and these aren't necessarily only visual hallucinations, they could also be other sensations, like hearing things, and these are usually vivid and detailed, and they seem very real, but, in fact, they aren't. The most common is actually auditory hallucinations, often in the form of voices, which could be like spoken commands or a running commentary, which would just be like voices in the background always talking, rather than directly at the person, or they could just be other sounds in general. Besides that, you could have visual hallucinations as well, and those are typically simple things like flashes of color, but some experience clear and identifiable objects like people or faces. And you can also extend this to other senses, like touch, smell and taste, but usually auditory and visual are the most common. So another symptom of psychosis besides delusions and hallucinations are those of disorganized behavior, which can be directly observed, and disorganized thinking, which can be indirectly observed through someone's speech, and there are several common types of speech that can suggest symptoms of psychosis. One is called poverty of content, where they don't actually give much information or don't say anything substantive when they're talking, or maybe they just say way more than what's needed to actually convey the message. Another speech pattern that can come about is getting off-topic when answering a question, which is called tangential speech, like the saying going off on a tangent. Sometimes they actually do answer the question, but it's in a totally roundabout way. Another pattern is thought blocking, where they've just suddenly lose their train of thought, and this can happen especially when there is a sudden interruption in what they're saying. There's also what's known as a word salad, where words are just put together and there's no sense or meaning in what's said, like, for example, dog sleep chicken pencil trees. The words are just jumbled together like they've been tossed in a salad bowl and then served out randomly. Finally there's preservation, where words or ideas are repeated, even after a particular topic has been switched. So, they're like preserving the last topic and then continuing to talk about it in the next topic. Finally, the patient might have symptoms of agitation and aggression, where if psychosis is left untreated, anxiety, heightened emotions, and heightened motor activity can all start to manifest. If someone has psychotic symptoms, though, there may be several underlying causes, and one might be simply other psychiatric conditions like schizophrenia or a brief psychotic disorder or others. But they might also have another medical condition like delirium, which is a state of mental confusion that's often accompanied by psychotic symptoms. But another culprit are things like substances like alcohol or hallucinogenic drugs like LSD, and finally, certain medications can also cause psychotic symptoms like anti-parkinsonism medications like Levodopa, and some anti-viral medication can also bring about psychotic symptoms.