In case of involutional paranoid, the leading one is paranoid syndrome in the form of interpretative delusions of pursuit of “small scope”, paranoid ideas of harm, jealousy, poisoning, attitude and influence. Delusions are characterized by a gradual development and, as a rule, a connection with premorbid personality traits. The onset of a mental illness is usually preceded by a prolonged overfatigue caused by family or domestic circumstances, somatic distress, but the massive trauma and severity of somatic diseases that patients with presenile depression do not occur. The nonsense does not have a generalizing, worldview character, does not completely isolate the patient from the usual concerns and interests, and does not fundamentally change the social and ethical attitudes of the person. Often before the occurrence of delirium, an increase in suspicion with respect to everyday phenomena is observed, as if an aggravation of sensitivity to various noises, sounds, unusual phrases said by someone from others occurs. The nonsense develops slowly, at first ideas of attitude and interpretation appear, then – persecution. The delusional plot is ordinary, petty, concrete, not prone to overgrowth. Therefore, at first, the patient’s statements do not raise doubts about their authenticity or are explained by the characteristics of their character and relations in the family, apartment, and workplace. Subsequently, the complaints of patients become more and more ridiculous, they begin to stubbornly assert that relatives, acquaintances, neighbors, employees get into their room, spoil things, steal objects, clothes, jewelry, and food. They “notice” suspicious stains on a tablecloth or blanket, “tightening” the threads on clothes, they say that the table or chairs are not in place. Patients explain the unpleasant sensations in the internal organs by the fact that in writing someone threw poison. Confirmation of this is considered the appearance or intensification of pain, if someone from the “ill-wishers” is nearby. Systematic, small-scale, with a specific content, delusional ideas of persecution, poisoning, jealousy and damage are usually emotionally saturated, accompanied by a violent expression of claims against “persecutors”. Patients’ behavior is active, they are not limited only to requests or exhortations to ill-wishers, they complain about them at the place of work or to the police, and, not having found support there, sometimes they themselves make an attempt to deal with them. Delusions are often accompanied by illusions and hallucinations: patients “hear” suspicious noise behind the wall, illegible voices, threats addressed to imaginary enemies, they feel an unpleasant smell or taste of food. In addition to the typical paranoid syndrome, with presenile delusional psychoses, depressive-paranoid, hallucinatory-paranoid are observed . and paraphrenic syndromes (R. G. Ilesheva, 1980; 10. E. Rakhalsky, 1980; E. A. Shcherbina, 1981). Patients with depressive-paranoid syndrome usually complain of a bad mood, express ideas of harm and poisoning, claim that they are allegedly accused of immoral behavior and various crimes, try to “rehabilitate themselves”, prove their innocence. They are restless, annoyingly complaining to others that they are undeservedly suspected, willingly talk about their fears, expecting sympathy from the interlocutor. Hallucinatory-paranoid syndrome is rare and is characterized by delusions of persecution and guilt, accompanied by auditory hallucinations, the intensification of which causes fear and anxiety and often leads to acts of auto-aggression. In paraphrenic syndrome, the ideas of persecution are joined by a delusion of greatness of a fantastic nature, accompanied by senestonatii, paresthesias and hallucinations. The course of presenile psychoses is often monotonous and long – from several months to several years. E. Ya. Sternberg (1979) considered their course without remission characteristic of presenile psychoses. According to other authors (E. A. Scherbina, 1981), many patients with presenile psychosis suffer 2-3 episodes of the disease. Most researchers agree that presenile psychoses, especially depressive forms, are characterized by either a single protracted state or a wave-like, remitting course with the subsequent disappearance of psychotic manifestations.