Depression affects more than one out of three survivors of critical illness, according to a Vanderbilt study released in The Lancet Respiratory Medicine, and the majority of patients experience their symptoms physically rather than mentally.

It is one of the largest studies to investigate the mental health and functional outcomes of critical care survivors, according to lead author James Jackson, Psy.D., assistant professor of Medicine, and it highlights a significant public health issue, with roughly 5 million patients admitted to intensive care units (ICUs) in the United States each year.

Weakness, appetite change and fatigue — all signs of somatic, or physical, depression — were present in two-thirds of the patients, as opposed to cognitive symptoms such as sadness, guilt or pessimism.

“We need to pay more attention to preventing and treating the physical rather than psychological symptoms of depression in ICU survivors,” Jackson said. “The physical symptoms of depression are often resistant to standard treatment with antidepressant drugs, so we need to determine how best to enhance recovery with a new focus on physical and occupational rehabilitation.”

The BRAIN-ICU study observed 821 critically ill patients ages 18-90 with respiratory failure or severe sepsis (blood poisoning) admitted to medical or surgical ICUs at Vanderbilt University Hospital and Saint Thomas Hospital.

Vanderbilt researchers assessed survivors for depression, PTSD, functional disability and impact on quality of life at three-month and one-year intervals, reporting that 149 of the 407 patients (37 percent) assessed at three months had at least mild depression, while only 7 percent of patients experienced symptoms of PTSD.

“Depression symptoms were significantly more common than symptoms of PTSD,” Jackson said. “And they occurred to a large degree across the entire age range. People tend to have a vision of a frail, older patient who goes to the ICU and is at risk for adverse mental health and, in particular, functional outcomes. But what people don’t anticipate is someone in their 20s, 30s or 40s could go to the ICU and leave with functional disability, depression or PTSD. These problems are not really a function of old age.”

One-third of the survivors who developed depression still had depressive symptoms at their one-year assessment, a statistic that Jackson said could, in part, be due to high expectations they set for rehabilitation.

“They have some arbitrary timeline set and they reach that date and they’re still not better and, in some cases, not a lot better at all,” he said. “Then what can happen is that depression can really worsen because they set this expectation that was really unrealistic and they feel like they have missed the goal.

“So that’s a big challenge, recalibrating expectations. This is especially hard for the many high-achieving, type A, patients that we might see who leave the ICU and want to get back to work right away, want to compete in the triathlon right away. They tend to have the hardest time,” he said.

Jackson said study authors gained additional perspective on their patients by doing at-home assessments following discharge.

“Home visits were the really interesting part of this,” Jackson said. “What it enabled us to do was to see patients in their real-life surroundings in actual circumstances in which they were sometimes a little more willing, I think, to disclose their problems. When you see someone in a hospital, the situation is a little more sterile. When you get to know them in their homes, we felt like you really get to know them and that was often the context where they told us about their depression.

“One thing we learned was that if people don’t have significant social support, they are profoundly limited in their ability to access care or improve in key areas,” he added.

Vanderbilt is now following ICU patients after discharge through the Vanderbilt ICU Recovery Center, which opened in late 2012, Jackson said.

The study was led by members of Vanderbilt’s ICU Delirium and Cognitive Impairment Group, which includes senior author Wes Ely, M.D., professor of Medicine, and co-author Pratik Pandharipande, M.D., MSCI, professor of Anesthesiology and Critical Care.

The research is supported by grants from the National Institutes of Health (AG027472, AG035117, AG034257, AG031322, AG040157, HL111111, and 2 T32 HL087738-06), and the Veterans Affairs Tennessee Valley Geriatric Research, Education and Clinical Center and the VA Clinical Science Research and Development Service.