People who have been treated in an intensive care unit (ICU) are at risk of developing what many call post-intensive care syndrome (PICS). PICS symptoms can include depression, anxiety, and PTSD (post-traumatic stress disorder), a recognized mental health condition.

Most often, many people think of PTSD as something that happens after a traumatic event such as war, an assault, or a bad accident. What some people may not realize is that an event such as sepsis, a life-threatening illness, is also an assault on the body. And by extension, a stay in an ICU with its 24-hour per day hustle and bustle, can also be an assault on the system.

A study published in the journal Intensive Care Medicine in 2008 used a survey to evaluate 107 patients who had sepsis from peritonitis, an abdominal infection.

The results showed that 28 percent of the 107 patients scored with moderate signs of PTSD and 10 percent scored higher. That is a total of 38 percent who experienced PTSD symptoms.

An earlier study published in 2001 in the journal Anaesthesia, found that 38 (47%) of 80 patients who responded to a questionnaire after discharge from an ICU reported significant anxiety and/or depression following their hospitalization. Thirty people complained of PTSD symptoms and 12 had levels that were considered to be consistent with a diagnosis of full PTSD.

And yet another study in 2004, published in the journal Intensive Care Medicine, found similar results. Researchers contacted 78 patients three months after they had been discharged from an ICU. Several of the patients showed signs of PTSD. Interestingly, they were found more frequently among the younger patients.

PTSD is not something that’s immediately obvious in many cases. Some people can walk away from an event and not think about what happened, focusing on other issues at first. But PTSD can sneak up on you and because it doesn’t happen right away, it may not be noticed or seem related to the issue that caused it in the first place.