In this paper I describe four different sources of acute acting-out behaviour as may be observed in long-term hospitalised patients suffering from severe personality disorders. I hope to demonstrate that acute psychological distress does not happen in a vacuum, but that specific intrapsychic and interpersonal dynamics within the hospital setting are at the root of what appears overtly as nonspecific emotional and behavioural disturbance. I argue that the hospital team's correct insight into the factors underlying acute acting-out is crucial to the implementation of therapeutic interventions aimed to decrease the patient's disturbed state of mind.