Social Isolation and Aging in Schizophrenia

Individuals diagnosed with schizophrenia and related psychotic disorders (SZ) exhibit a markedly elevated risk of premature mortality, with a 10-20-year shorter lifespan relative to the general population. Increased mortality rates in SZ are largely attributable to the early manifestation of medical conditions that normally occur later in life, a process known as 'accelerated aging'. While unhealthy lifestyle behaviors, such as smoking and unhealthy diet, account, in part, for accelerated aging in SZ, the excess of physical comorbidities cannot be solely attributed to these factors. Remarkably, the direct adverse health effects of key clinical characteristics of SZ have rarely been considered. In the general population, the absence of social contact is known to pose enormous challenges for physical health, especially at older ages. Given that social isolation is a persistent and disabling feature of SZ, it is possible that this behavior may contribute to the premature manifestation of health conditions in SZ. Building on rich pilot data pointing to significant associations between social isolation and long-term perceived health in SZ, the overarching goal is to test whether and how social isolation contributes to the health challenges of individuals with SZ as they age. With participants from Europe (EU-GEI) and the US (Olin Neuropsychiatry Research Center), the researchers will create a longitudinal database of 650 participants, including 500 individuals with SZ, and 150 of their unaffected siblings. The researchers will apply an accelerated longitudinal design by reassessing and by examining medical records of research participants who were first evaluated between the ages of 20-55 and are now 40-70 years of age, a period when many medical conditions and health problems tend to manifest. The researchers will determine the age-related association between social isolation and adverse health outcomes in SZ, test for familiality, directionality, and factors moderating this association, and determine the extent to which the COVID-19 pandemic and the resulting imposed lockdowns impacted health in SZ. The researchers will consider generalizability across countries, sexes, and race/ethnicities. The rationale for the proposed research is that in order to facilitate much-needed targeted therapies to prevent early mortality in SZ, the researchers need to better understand factors that contribute to the excess of medical comorbidities in SZ. The central hypothesis is that social isolation, a common and persistent characteristic of SZ, contributes to the excess of physical comorbidities in SZ. To meet the overall goal, the following aims are: (1) Determine the association between social isolation and adverse health outcomes in SZ; (2) Test for the directionality, and moderating factors, of the association between social isolation and health outcomes in SZ, and; (3) Examine whether the COVID-19 pandemic modified associations between social isolation and health outcome in SZ. This study will be the first to comprehensively examine the health impact of social isolation in SZ.