Mood disorder diagnoses are known to be associated with poorer long-term outcomes for a range of disorders. Growing evidence suggests that SARS-CoV-2 may affect brain function directly or indirectly. This has given ground to concerns that interaction between preexisting disorders involving the central nervous system (CNS), including mood disorders, and adverse outcomes. In their study published in the American Journal of Psychiatry, Castro et al have shown that hospitalized individuals with a history of mood disorder may be at risk for greater COVID-19 morbidity and mortality and are at increased risk of need for postacute care.
While the pulmonary consequences of COVID-19 have contributed substantially to its morbidity and mortality, its extrapulmonary CNS manifestations like delirium, and stroke as well as other neurologic presentations have also been documented. But it remains unsettled whether these manifestations are a consequence to direct viral injury or indirect insult due to cytokine storm. The study by Castro et al sheds light on some of these questions.
They aimed to determine whether past diagnosis of mood disorder or current symptoms were associated with differential hospital outcomes, as a means of understanding clinical features that might inform clinical decision making and identify higher risk clinical subpopulations.
Associations between history of mood disorder and in-hospital mortality and hospital discharge home were examined using regression models among any hospitalized patients with COVID-19 positive tests.
Among 2,988 admitted individuals, 717 (24.0%) had a prior mood disorder diagnosis. In Cox regression models adjusted for age, sex, and hospital site, presence of a mood disorder prior to admission was associated with greater in-hospital mortality risk beyond hospital day 12. These risks were not entirely attributable to sociodemographic differences, nor to differences in burden of medical or neuropsychiatric comorbidity, BMI, or smoking history.
A mood disorder diagnosis was also associated with greater likelihood of discharge to a skilled nursing facility or other rehabilitation facility rather than home.
Most notable is the time dependence of elevated mortality risk, evident in the survival curves: while there was little or no difference in early hospitalization, there was marked divergence by week 2. It may reflect the commonly observed consequences of cytokine storm and broader immune-mediated effects among individuals who initially appeared to improve during hospitalization.
"Taken together, our results underscore the pressing need to better understand potential CNS effects of COVID-19 and how they may interact with preexisting psychiatric illness", noted the authors. Beyond the potential impact of hyperperfusion or hypoxia, the systemic immune response, particularly cytokine release syndrome, may contribute to CNS effects of COVID-19.
To date, most reports of so-called asymptomatic presentations focus on pulmonary symptoms or general symptoms of infection alone. This study underscores the importance of including symptoms of neurologic and psychiatric illness in COVID-19 surveillance efforts.
In aggregate, this large, multihospital retrospective cohort study suggests that psychiatric comorbidity, and mood disorders in particular, must be carefully considered in hospitalized COVID-19 patients.
Source: American Journal of Psychiatry: https://doi.org/10.1176/appi.ajp.2020.20060842