Short answers, pulled from the story.
Psychosis is the inability to distinguish what is or is not real, characterized by symptoms such as hallucinations, delusions, and disorganized thought. It is a description of a person's state or symptoms, not a particular mental illness. Psychopathy is a separate personality construct characterized by impaired empathy and remorse, along with bold, disinhibited, and egocentric traits; the two conditions are unrelated.
Auditory hallucinations, particularly hearing voices, are the most common and often prominent feature of psychosis. Other core symptoms include delusions, such as persecutory beliefs or thought broadcasting, disorganized speech and thought, and negative symptoms like reduced emotional expression, decreased motivation, and anhedonia. When voices are present, the average number has been estimated at three.
Psychosis can be caused by psychiatric disorders such as schizophrenia and bipolar disorder, traumatic life events, substance use including cannabis and methamphetamine, severe sleep or sensory deprivation, and a wide range of medical conditions including autoimmune disorders, nutritional deficiencies, thyroid disease, and electrolyte disturbances. Individuals with psychotic symptoms are three times more likely than the general population to have experienced childhood trauma.
Cannabis use is associated with increased risk of psychotic disorders, and more frequent use correlates with higher risk. Cannabis use before age 15 may increase the risk of psychosis in adulthood. THC, one of the active compounds in cannabis, can induce psychotic symptoms in healthy individuals, while limited evidence suggests that CBD, another active compound, may have antipsychotic effects.
The first clinical trial of antipsychotics for the treatment of psychosis took place in 1952. Chlorpromazine, sold under the brand name Thorazine, became the first antipsychotic medication approved for the treatment of both acute and chronic psychosis. Its mechanism of action as a dopamine antagonist was not understood until 1963.
Cross-cultural studies show that the content and emotional character of psychotic experiences vary significantly by cultural context. In the United States, people with psychosis tend to describe hallucinations as violent and self-identify as crazy. In Accra, Ghana, voices are more often described as spiritually meaningful and positive. In Chennai, India, hallucinations are frequently described as family members or friends offering guidance. Researchers attribute these differences to social kindling, in which a person's social context shapes how they interpret and experience unusual sensations.