Neuropsychiatric Disease and Treatment (Jan 2020)
The Relationship Between Course of Illness and β-Endorphin Plasma Levels in Patients with Schizophrenia
Abstract
Małgorzata Urban-Kowalczyk,1 Magdalena Kotlicka-Antczak,1 Dominik Strzelecki,1 Ewa Rudecka,2,3 Janusz Śmigielski4 1Department of Affective and Psychotic Disorders, Medical University of Łódź, Łódź, Poland; 2Babiński Memorial Hospital in Łódź, Łódź, Poland; 3Faculty of Human Nutrition and Consumer Sciences, Warsaw University of Life Sciences SGGW, Warsaw, Poland; 4State High Vocational School in Konin, Konin, PolandCorrespondence: Małgorzata Urban-KowalczykDepartment of Affective and Psychotic Disorders, Medical University of Łódź, Czechosłowacka 8/10, Lodz 92-216, PolandTel +48 42 675 73 71Fax +48 42 675 74 03Email [email protected]: Extensive investigations have been conducted into predictors of schizophrenia outcome. The heterogeneity of the illness implies that many factors should be taken into account. Some studies have reported the relationship between increased β-endorphin concentration and predominant negative symptoms.Methods: We included 77 outpatients with schizophrenia and 74 healthy controls. Data referring to duration and course of illness, hospitalization number and treatment were collected on the basis of clinical interviews and medical documentation analysis. The β-endorphin concentrations were assessed once in all participants, at the onset of the study.Results: A chronic course of illness was found in 44 of the 77 schizophrenics. Patients with schizophrenia, especially those with a chronic course of illness, revealed significantly higher β-endorphin concentrations than those with an episodic course and controls (mean 29.70 vs 19.86 pmol/L; p=0.0001). Increased levels of β-endorphin were related to longer duration of illness (R=0.294, p=0.009) and frequent psychiatric hospitalization (R=0.346, p=–0.002).Conclusion: Endorphins may be potential biological predictors of persistent negative symptoms and final outcome in schizophrenia.Keywords: β-endorphin, dopamine, opioid peptides, schizophrenia
