At least 5 million patients are admitted to medical or surgical intensive care units (ICUs) in North America every year—more than the number of patients who are diagnosed with cancer. Of the 80% who survive and are discharged from the ICU, improvement in their physical status may be complicated by lingering depression, post-traumatic stress disorder (PTSD), and a loss in functional abilities. Understanding the incidence of these outcomes brings us a step closer to treating—and perhaps preventing—them.
Medical and technological advances have significantly increased the survival rate of ICU patients but poor mental health outcomes and functional disabilities after discharge from the ICU continue to be common in these patients. Zeroing in on the association between critical illness and mental health outcomes, such as depression and PTSD, has become a focus for research. A recent study suggests that 30% of ICU patients experience some level of depression a year after discharge and that depression is five times more prevalent than PTSD in ICU survivors.
The study, published in The Lancet, was conducted by Dr. James Jackson, a psychologist, and his colleagues as part of the ongoing BRAIN-ICU study conducted under the auspices of the National Institutes of Health. The Brain-ICU study seeks to identify risk factors of long-term cognitive impairment in ICU patients with the goal of shedding light on preventive and treatment strategies that may reduce their incidence, severity, and duration. Researchers measured the incidence of depression, PTSD, and functional disability in survivors of critical illness at 3 months and 12 months post-discharge from the ICU with a focus on a possible correlation with the patient’s age and duration of delirium. The study also probed the question of whether post-ICU depression is most frequently somatic (physical complaints) versus cognitive (thought- or mood-related) in nature.
Funding for the study was provided by the National Institutes of Health and by the Geriatric Research, Education, and Clinical Center (GRECC) of the Department of Veterans Affairs.
Subjects in this study were 821 patients undergoing treatment for respiratory failure or shock in medical or surgical intensive care units in Nashville. The median age of these patients was 61. Patients were assessed for depression using the Beck Depression Inventory II, for post-traumatic stress disorder (PTSD) using the Post-Traumatic Stress Disorder Checklist—Event Specific Version, and for functional disability measured by the activities of daily living scales, the Pfeffer Functional Activities Questionnaire, and the Katz Activities of Daily Living Scale.
At 3 months post-discharge, 37% of the patients showed signs of some level of depression; at 12 months post-discharge, 33% showed signs of depression. Study findings suggest that those patients who experienced more severe depression in the 3 months after critical illness experienced persistent, although perhaps less severe, depressive symptoms at 12 months. Depression occurred even in patients with no previous history of depression.
Depression was almost five times more prevalent than PTSD in these post-critically ill patients with only 7% of the patients exhibiting symptoms of PTSD. Functional inabilities to perform basic activities of daily living were evident in 32% of the patients at 3 months post-discharge and in 27% of patients at 12 months post-discharge.
Although delirium and functional disabilities are commonly linked to increased age, researchers found no consistent correlation between delirium and depression, PTSD, or functional disabilities. These outcomes occurred across the spectrum of patient ages.
This study joins a growing body of evidence that links critical physical illness to mental health outcomes, supporting the mind-body connection. Moreover, those ICU patients who showed signs of depression exhibited somatic symptoms, such as weakness, change in appetite, and fatigue, rather than cognitive symptoms such as feelings of hopelessness or loss of interest in daily life. These findings suggest that ICU survivors may benefit from gearing therapies toward physical rather than cognitive symptoms. Doing so could open the door for nonpharmacological interventions that include physical and occupational rehabilitation to improve the recovery of critically ill patients.