Disparities in Longevity: Increased Morbidity Among Individuals with Serious Mental Illness

Background and Purpose: People with serious mental illness (SMI) are a vulnerable population with high rates of morbidity and mortality.  Studies show a staggering 25 year difference in mortality among SMI individuals compared to those in the general population. An important consideration is the burden of co-morbid disease that impede upon individuals’ life course and recovery. Little is known about distinguishing characteristics of SMI, in particular, schizophrenia and bipolar disorder, in community epidemiologic samples because much of the research comparing these two SMI’s has stemmed from clinical samples. The aim of this study was to compare clinical status of individuals with psychosis, bipolar disorder, and neither condition to understand patterns of comorbidity in an epidemiologic sample. 

Methods: We use data from the 2001-2002 National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) to examine differences in sociodemographic characteristics, and medical, psychiatric, and substance use comorbidities individuals with a lifetime history of schizophrenia or psychotic episode (SPE; n = 386) in comparison to individuals with a history of bipolar disorder (BPD) but no psychosis (n = 1,276) and to the general population without one of these conditions (n = 41,431).   NESARC was designed to examine alcohol use disorder and associated disabilities in the general population and to observe changes over time. Chi-square analyses were used to compare differences across groups for categorical variables. Odds ratios were calculated to assess associations between sociodemographic characteristics, employment status, perceptions of health, psychiatric, medical and alcohol and substance use comorbidities among individuals with SPE, bipolar disorder, and the general population.

Results: In this national community sample, people with a history of SPE or BPD had more medical (e.g. cardiovascular disease: (OR=3.77; CI 2.63, 5.41 & OR= 2.7; CI 2.10,3.53) respectively), substance use (OR=2.80; CI 2.11,3.73 & OR=3.47; CI 2.96,4.06, respectively), and psychiatric comorbidities (e.g. any anxiety: OR=4.57; CI 3.40,6.14 & OR=6.53; CI 5.59,7.62, respectively) than the general population.  In comparison to adults with BPD but no psychosis, those with SPE functioned more poorly on several measures.  Specifically, although educational achievement was similar between these groups, people with SPE were more likely to be unemployed (OR=2.18; CI 1.43, 3.32) and permanently disabled (OR=7.24; CI 4.21, 12.47). Personal income was far lower in the SPE group as was the rate of current marriage (40.31% vs. 51.73%, respectively). 

Conclusion and Implications: The goal of the study was to provide a better understanding of the disease burden of individuals with SMI to inform clinicians who recommend treatments and other decision makers who develop or allocate services and treatment resources. SMI has a substantial adverse impact on the lives and longevity of affected individuals.  Individuals with a history of SPE and BPD experience a significant number of medical and psychiatric comorbidities and report markedly worse functioning compared to individuals without these disorders.  Extensive prevention and intervention efforts to treat medical and psychiatric conditions, limit disability, and promote recovery are warranted in order to bridge the longevity disparities that currently exist.