The negative symptoms of schizophrenia primary and secondary, deficit syndrome, persistent negative symptoms

The diagnosis and treatment of the negative symptoms of schizophrenia belong to the most important challenges of modern psychiatry. In recent years, many attempts have been made to systematise our knowledge about their structure, pathogenesis, and clinical picture. Currently, blunted affect, alogia, social withdrawal, anhedonia, and avolition are recognised as the negative symptoms of schizophrenia. The negative symptoms can be divided into primary and secondary ones. Primary negative symptoms form an integral part of the schizophrenic process, have stable clinical course, and are resistant to treatment. Secondary negative symptoms result from additional symptoms and factors connected with schizophrenia, such as positive (psychotic) symptoms, depression, anxiety, side effects of medications, addictions, and social deprivation. Carpenter et al. introduced a concept of deficit schizophrenia (DS), used interchangeably with the term deficit syndrome, for patients with schizophrenia with primary and chronic negative symptoms. In research practice, the concepts of prominent negative symptoms and predominant negative symptoms are proposed to identify groups of clinically defined patients. In order to standardise diagnostic criteria, a concept of persistent negative symptoms (PNS) has been proposed.

The PNS are negative symptoms resistant to treatment, decreasing the ability of normal functioning, and present in periods of clinical stabilisation. In this article, in addition to a broader discussion of the above issues, current data on neurobiology of the deficit syndrome and persistent negative symptoms are also presented.