Xerostomia in Schizophrenia and Bipolar Patients: Is There Any Relation?

Psychiatric disorders such as bipolar disorder and schizophrenia cause vascular, neurological, and neurobiological changes. On other hand, salivary glands are influenced by changes in the autonomic nervous system. Therefore, this  hypothesis was formed that psychiatric disorders can affect salivary glands through neurological pathways. This study aimed to evaluate if schizophrenia and bipolar disorder can cause xerostomia and lip dryness in patients who are not using psychiatric drugs.

This study included 54 bipolar and 50 schizophrenia whose disorder was confirmed, and the control group included 60 healthy individuals whose mental health was evaluated through GHQ21 questionnaire and a psychiatrist. The FOX questionnaire was also completed to diagnose Xerostomia and lip dryness. Data were analyzed by SPSS version 22 using Chi-square, t-independent, logistic 
regression, ANOVA, Tukey test, Kruskal–Wallis, Mann–Whitney and Spearman 
correlation.

In this study, xerostomia was found in the bipolar group (57/40%), 
schizophrenia group (66%) and control group (18/33%). Xerostomia and dry lips were significantly higher in psychiatric patients than in the control group, but there was no significant difference between bipolar patients and schizophrenia patients. In this study, there was no significant relationship between Xerostomia and age and gender.

Neurological changes are factors that affect salivary secretions causing Xerostomia. Dentists must always consider psychological factors as a causative agent of Xerostomia.