Shared psychotic disorder (also called folie à deux): This illness happens when one person in a relationship has a delusion and the other person in the relationship adopts it, too.
Substance-induced psychotic disorder: This condition is caused by the use of or withdrawal from drugs, such as hallucinogens and crack cocaine, that cause hallucinations, delusions, or confused speech.
Psychotic disorder due to another medical condition: Hallucinations, delusions, or other symptoms may happen because of another illness that affects brain function, such as a head injury or brain tumor.
Paraphrenia: This condition has symptoms similar to schizophrenia. It starts late in life, when people are elderly.
The main ones are hallucinations, delusions, and disordered forms of thinking.
Hallucinations means seeing, hearing, or feeling things that don’t exist. For instance, someone might see things that aren’t there, hear voices, smell odors, have a “funny” taste in their mouth, or feel sensations on their skin even though nothing is touching their body.
Delusions are false beliefs that don’t go away after even after they’ve been shown to be false. For example, a person who is certain his or her food is poisoned, even if someone has shown them that the food is fine, has a delusion.
Other possible symptoms of psychotic illnesses include:
- Disorganized or incoherent speech
- Confused thinking
- Strange, possibly dangerous behavior
- Slowed or unusual movements
- Loss of interest in personal hygiene
- Loss of interest in activities
- Problems at school or work and with relationships
- Cold, detached manner with the inability to express emotion
- Mood swings or other mood symptoms, such as depression or mania
People don’t always have the same symptoms, and they can change over time in the same person.