Mental disorders after critical illness: depression, PTSD and functional disability in survivors of intensive care


Earlier this year I reported from the Woodland on the results of Wunsch’s Danish cohort study looking at the burden of psychiatric illness and psychoactive medication prescriptions prior to nonsurgical critical illness, as well as whether the risk of psychiatric illness and psychoactive medication use after nonsurgical critical illness was increased among patients with no prior psychiatric history.

Well mental disorders after critical illness seem to be a popular area of research, as Jackson et al have recently published the results of a longitudinal cohort study looking at depression, PTSD and functional disability in survivors of critical illness (BRAIN-ICU study).

At least 5 million individuals are admitted to medical or surgical critical care units in North America every year (more than are diagnosed with cancer) and about 80% survive. For these patients, critical illness can be a gateway to post-intensive care syndrome, which includes cognitive impairment, depression, post-traumatic stress disorder (PTSD), functional disabilities, and decrements in quality of life.

This study published in the Lancet Respiratory Medicine in May 2014 aimed to:

  • Characterise mental health outcomes and functional disabilities in a general ICU population and to explore the hypothesis that depressive symptoms after discharge are more often somatic (i.e. bodily complaints) than cognitive-affective (i.e. thought-related and mood-related complaints).
  • Test the effects of age across outcomes, with the hypothesis that younger patients have much the same symptoms of depression, PTSD, and functional disability as do older patients.
  • Determine if delirium is a risk factor for poor mental health and functional outcomes at 3 month and 12 month follow-up, testing the hypothesis that delirium is associated with depression, PTSD, and functional disabilities.
The BRAIN-ICU study is a prospective multi-centre cohort study from ICUs in Nashville, Texas.

The BRAIN-ICU study is a prospective multi-centre cohort study from ICUs in Nashville, Texas.


This was a prospective, multi-centre observational cohort study. They enrolled patients with respiratory failure or shock who were undergoing treatment in medical or surgical ICUs in Nashville, TN, USA.

They obtained data for baseline demographics and in-hospital variables, and assessed survivors at 3 months and 12 months with measures of:

  • Depression (Beck Depression Inventory II)
  • Post-traumatic stress disorder (PTSD, Post-Traumatic Stress Disorder Checklist – Event Specific Version)
  • Functional disability (activities of daily living scales, Pfeffer Functional Activities Questionnaire, and Katz Activities of Daily Living Scale)


Initial enrolment was 821 patients with a median age of 61 years (IQR 51–71):

  • 3 months assessment: 448 patients
  • 12 months assessment: 382 patients


  • At 3 months: 149 (37%) of 406 patients reported at least mild depression,
  • At 12 months: 116 (33%) of 347 patients reported at least mild depression; this depression was mainly due to somatic rather than cognitive–affective symptoms.
  • Depressive symptoms were common even among individuals without a history of depression (as reported by a proxy), occurring in 76 (30%) of 255 patients with data at 3 months and 62 (29%) of 217 individuals at 12 months.


  • Only 7% of patients (27 of 415 at 3 months and 24 of 361 at 12 months) had symptoms consistent with PTSD.

Activities of Daily Living

  • Disabilities in basic activities of daily living (ADL) were present in:
    • 139 (32%) of 428 patients at 3 months
    • 102 (27%) of 374 at 12 months

Mental health and functional difficulties were prevalent in patients of all ages. Although old age was frequently associated with mental health problems and functional disabilities, they observed no consistent association between the presence of delirium and these outcomes.

Poor mental health and functional disability is common in patients treated in intensive-care units

Critical illness may be improved but what other damage is left?

Critical illness may be improved but what other damage is left?


This was a large cohort study using a mixed ICU population and robust validated tests. The main results were:

 depression was five times more frequent than post-traumatic distress disorder in ICU survivors

It was noted that depression was driven by somatic symptoms, suggesting approaches targeting physical rather than cognitive causes could benefit patients leaving critical care. A third of intensive care patients develop depression that typically manifests as physical, or somatic, symptoms such as weakness, appetite change, and fatigue, rather than psychological symptoms.

Risks of psychiatric illness increase post ICU

Risks of psychiatric illness increase post-ICU

Second, it was noted that patients in this large cohort (including many with no reported history of psychiatric treatment) had mental health and functional deficits across the spectrum of age (although functional disability and mental health quality of life were worst with old age), and the authors did not observe a consistent association between delirium and long-term outcomes of interest.

The study also suggests that individuals with more severe depression in the early post-critical illness recovery period (3 months) tend to have persistent depressive symptoms at 12 months, although symptom severity might decrease slightly. Consistent with Wunsch’s reporting of higher level of symptoms at 3 months than 12 months.

Management of somatically depressed ICU survivors could present an opportunity for non-pharmacological intervention through physical and occupational rehabilitation

This paper continues to add weight to the evidence base with regards to the most extreme physical ill health increasing risk of onward mental health; helping to confirm that the body and mind really are connected; even in Texas…


Jackson JC, Pandharipande PP, Girard TD, Brummel NE, Thompson JL, Hughes CG, Pun BT, Vasilevskis EE, Morandi A, Shintani AK, Hopkins RO, Bernard GR, Dittus RS, Ely EW; Bringing to light the Risk Factors And Incidence of Neuropsychological dysfunction in ICU survivors (BRAIN-ICU) study investigators. Depression, post-traumatic stress disorder, and functional disability in survivors of critical illness in the BRAIN-ICU study: a longitudinal cohort study. Lancet Respir Med. 2014 May;2(5):369-79. 

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