Epidemiology and treatment of psychiatric conditions that develop after critical illness

As a greater number of patients survive critical illness, there is increasing interest in accelerating patients' recovery after intensive care unit discharge. There is compelling evidence that psychiatric illnesses such as depression impair functional status in patients with chronic medical illnesses. Therefore, psychiatric conditions that develop after critical illness are a logical target for treatment or prevention strategies to improve recovery after critical illness.

This is a new area of investigation for intensive care unit researchers. To date, most studies have focused on descriptive epidemiology of psychiatric conditions at varying times after intensive care unit discharge. Small randomized trials have shown that depression and posttraumatic stress symptoms can be reduced by interventions during or after mechanical ventilation, although the causal mechanisms leading to these improved outcomes are obscure. Promising results must be confirmed in additional trials. After acute myocardial infarction, large trials have found that psychosocial interventions started after hospital discharge are ineffective at preventing psychosocial impairment.

Psychiatric symptoms and disorders affect 15%-35% of patients months after intensive care unit discharge. There is no consistent evidence that antidepressant medications are safe or effective in critically ill patients. Understanding the causal pathways that lead from acute medical stress to neuronal alterations and subsequent psychiatric symptoms will allow more precise targeting of preventive interventions.