Paranoia - a rare type of chronic psychosis, usually beginning in adulthood, which is characterized by the gradual development of logically constructed monothematic systematized delusional ideas (sometimes at first — in contrast to schizophrenia, there is no progression of negative symptoms and personality changes (that is, there is no increase in apathy, abulia, a decrease in energy potential and an outcome in an emotional-volitional defect) and no perception disorders (illusions or hallucinations).Paranoid people are also distinguished from other psychotic patients by purposeful, orderly, consistent, and to some extent predictable behavior. Despite the persistent delusional symptoms, patients with paranoia are usually able to function in society, and, in comparison with patients with schizophrenia, have greater opportunities for "integration in life". In the classical view, paranoid sufferers are characterized by unhealthy suspicion, a tendency to see in random events the machinations of enemies, to build complex conspiracy theories against themselves, while maintaining logical thinking in the other. In paranoia, the content of pathological situations often includes many elements of reality that are formally plausible related to the patient's painful ideas, or are based on them.