Autoimmune paraneoplastic encephalitis is a rare and newly described group of diseases involving autoantibodies directed against antigens on the surface of synaptic and neuronal cells. It contains a wide range of neuropsychiatric symptoms. Sensitive and specific diagnostic tests such as the cell test are fundamental for the detection of antibodies on the surface of neuronal cells in the cerebrospinal fluid or serum of the patient and determine treatment and monitoring. Since neurological symptoms are fairly well described in the literature, this paper focuses on the nature of psychiatric symptoms that occur at the onset or during the course of the disease. To aid in diagnosis, the main neurological symptoms of the most representative synaptic and neuronal cell surface autoantibodies are detailed. The investigation of these autoantibodies during almost a decade has allowed us to present an overview of the frequency of autoimmune encephalitis in psychiatric diseases and general guidelines for the management of psychiatric manifestations. For most autoimmune encephalitis, the prognosis depends on the speed of detection, identification and treatment of the disease. Since the presence of pronounced psychiatric symptoms leads patients to psychiatric institutions and can make it difficult to establish a diagnosis, the aim of this work is to provide indications that will help health professionals in earlier detection and thus provide better medical care to patients. For most autoimmune encephalitis, the prognosis depends on the speed of detection, identification and treatment of the disease.