This paper reviews the literature related to the Intensive Care Unit (ICU) Syndrome. The intention of the paper is to explore the range of psychotic and affective phenomena that may be observed in practice, together with the management of contributory stressors. Patients experience a range of psycho-affective disturbances that may be triggered by drugs, the environment, dehumanizing practices and sleep deprivation. Symptoms do not always disappear following discharge and further research is required to determine the long-term psychological effects of an ICU. Comprehensive assessment of the patient's psychological state, using an appropriate tool, is necessary and should form an integral part of ongoing care. Interventions identified include eradication of dehumanizing behaviour, modification of environmental stimuli, effective communication and therapeutic touch. Where possible, communication needs should be addressed prior to admission, and patients and their families prepared for the unfamiliar world of the ICU.