Trauma causing ongoing impairment or distress symptom clusters: re-experiencing (intrusive thoughts, trauma memories, nightmares), avoidance (of thoughts, memories, reminders/triggers), thinking/mood changes (blame/guilt, selective amnesia, numbing, loss of interest, disconnection from others) and arousal/reactivity (sleep and concentration difficulties, hypervigilance, heightened startle reflex, irritability, unprovoked aggression).