Introduction
Schizophrenia-spectrum and bipolar-spectrum disorders are severe mental illnesses (SMIs) characterized not only by profound psychiatric symptoms but also by a high burden of physical comorbidities. People living with these conditions have markedly reduced life expectancy, often attributable to co-occurring physical diseases. While numerous studies have documented individual physical comorbidities such as cardiovascular or metabolic disorders, less is known about the epidemiology of systemic physical multimorbidity—defined as the accumulation of multiple chronic physical diseases spanning different organ systems—among this population. Understanding patterns and timing of multimorbidity onset is crucial for guiding clinical management and preventive strategies.
