Hallucinations and delusions are common aspects of psychotic episodes, according to National Alliance on Mental Illness. Psychosis is a symptom of mental or physical illness, trauma, extreme stress, or substance abuse. A psychotic episode may cause a person to appear unpredictably angry or to behave in a disorganized and incoherent manner.
Hallucinations are characterized by experiencing things that aren't really there, such as by seeing, hearing or feeling them, states NAMI. Some psychotic hallucinations include seeing people or things transform and take the shape of something else. Psychotic individuals may also feel things crawling on their skin or hear voices instructing them to cause harm to others or to themselves. Delusions are unlikely or irrational beliefs, such as believing that an external force has control over one's mind, emotions and behavior. A delusional person may think he has special powers or that random, everyday events have special meaning or significance.
Psychotic events may be preceded by warning signs, according to NAMI. Some early signs of psychosis include trouble concentrating or thinking clearly, a drop in overall performance at work or school, a decline in self-hygiene or self-maintenance, spending more time alone than usual, or having unfounded suspicion of others. Whether psychosis is due to brain tumor or infection, epilepsy, or mental illness, identifying, diagnosing and treating it early on can prevent the underlying illness from progressing.