Psychosis is a general term for psychotic disorders. Psychotic disorders are mental disorders (mental illness), or brain disorders, which include schizophrenia, schizoaffective disorder, psychotic depression, psychotic mania, substance-induced psychosis, and psychosis due to a general medical condition. The core feature of psychosis is that the person has difficulty figuring out what is real, and what is not real.
People without psychosis take for granted that when they hear a voice, they can decipher where the voice is coming from: from the person standing next to them; from the radio; or from their own thoughts. People without psychosis also take for granted that they can check out if their belief about something is true or false; for example, if they hear a noise in their house late at night and this leads them to believe there is an intruder in the house, they can check and find out that the cat tipped over something, and not think any more of it. So basically, if you don’t have psychosis, you are able to tell what is real, and what is just your imagination.
A person with psychosis is not as fortunate. They have problems knowing what reality is. If they hear a voice, they think it is real, despite no one else around them that would be a logical source of the voice. If they hear a noise, they may think someone is after them, or trying to kill them, despite no other external evidence that this is the case. A person with psychosis lives life not knowing what is real, and what is not real. So this is called impaired reality testing, where you don’t have the ability to distinguish or to check out if something is real, or just your imagination.
If you have psychosis, you have impaired reality testing. You have hallucinations, which are sensory experiences from one of your senses which have no obvious external source. The most common hallucination in psychosis is auditory, or hearing voices. When you ask someone who has auditory hallucinations where the voice are coming from, from the inside or the outside of their head, they will say the voices come from outside their head. If it came from inside your head, this is most likely your own thoughts, but people with psychosis tend to say that their voices come from the outside.
If you have psychosis, you have impaired reality testing. You have delusions, which are fixed, false beliefs, which have no basis or evidence in being true. A common delusion in psychosis is paranoid delusions, or paranoia. A person who has paranoid delusions is not able to give you logical evidence that the delusion is true. They may believe the FBI or the CIA are trying to kill them, despite no concrete evidence that this is so.
If you can imagine, having impaired reality testing is highly distressful, and many people with psychosis have contemplated suicide to end the misery of psychosis. The good news is that psychosis is treatable, and you can lead a normal life again if you stay the course and do the work necessary to extinguish the psychotic symptoms, deal with the depressive symptoms, overcome the cognitive deficits, and work on activities of daily living. This seems like a lot of work, but with perseverance, time, and support, you can overcome these barriers and lead a normal life again.
In my years of experience treating hundreds of people with psychosis, the most devastating aspect of the illness is how it destroys the disordered person when they lament the loss of their previous life and functioning. This pain on reflection of their previous life comes about when their active psychotic symptoms are treated and they have an opportunity to reflect on their life lost. This is why it is important to instill hope into the disordered person, as they can regain much of their previous functioning through diligence and hard work in treatment and psychosocial rehabilitation.