Comorbid physical illnesses in adult outpatients with psychotic disorders: risk factors, psychological functioning, and quality of life outcomes

Purpose In contrast to global research, where physical comorbidity in psychotic disorders is established, only a few studies have been conducted in Southeast Asia. With a concerning trend of chronic physical illnesses emerging in adults below the age of 65, an investigation into comorbid chronic physical illnesses in adults diagnosed with psychotic disorders is necessary. This study aims to explore the risk factors, psychological functioning, and quality of life outcomes associated with comorbidity in adults below the age of 65, diagnosed with psychotic disorders, in a multi-ethnic non-Western setting. Methods Electronic medical records of 364 patients with psychotic disorders who had provided written consent to participate were screened for co-occurring physical conditions. The majority of participants were female (53.7%), Chinese (69%), single (74.5%), and had tertiary and above education (43%). They were approximately 35 years old on average and the mean age of onset for psychosis was 26.7 years old. Results Comorbid physical illnesses were present in approximately a third of adults with psychotic disorders (28%). They typically reported cardiovascular-related diseases, respiratory, and skin conditions. Comorbidity was significantly related to lower physical quality of life. As compared to other types of psychotic disorders, schizophrenia was significantly related to a greater frequency of comorbid physical conditions. Multinomial regression analyses revealed that age, age of onset, Malay and Indian ethnicities were significant factors. Conclusion Physical comorbidity in adults below the age of 65 is common, signifying an emerging need to place greater attention into the screening and emphasis on the physical care needs of this age group. Finally, more research is needed to understand the impact of common co-occurring acute and chronic cardiovascular, skin, and respiratory diseases locally.