Abstract
The observation that chronic disorders occur together frequently has become of increasing interest as it is now viewed as the norm and not the exception. Of concern is the increasing trend of comorbidity in younger populations especially in areas of socioeconomic deprivation and low income countries. There are reasons why comorbidity is of great importance not only in the context of diagnostic classification, aetiology and pathogenesis but also for models of health-care delivery, rationalisation of pharmacotherapy, patients’ self management and the complex simultaneous utilisation of health-care systems. There is a need, therefore, for a better understanding of the coexistence of various diseases in order to develop more effective and cost-effective interventions to improve health and social outcomes. Comorbidity in medicine is now viewed as one of the major challenges in the twenty-first century in terms of prevention and treatment. With comorbidity comes the increasing risk of mental health problems especially depression leading to potentially more complications and worse prognosis overall. It is already well established that those with severe mental illness suffer increased comorbid conditions and a reduced life expectancy due to predominantly comorbid cardiovascular problems. Fragmentation in the health-care system and the current single disease model only exacerbate the problem of effectively helping people experiencing comorbidities and especially comorbidities involving both mental and physical conditions. New ways of thinking are required to redesign healthcare systems for the development of effective early intervention and screening to treat coexisting conditions and enable clinicians to deliver more integrated person-centred care to improve health outcomes and quality of life for this population.