Letter. Understanding the mechanism of psychogenic non-epileptic seizures (PNES) is challenging. A recent review grouped currently hypothesised psychological models into four: (1) traumatic dissociation, (2) hard-wired anxious-arousal responses, (3) conversion defences and (4) conditioned behaviours, but concluded that determining which of these was correct, if any, went far beyond the available evidence.1 . To read the full article, log in using your NHS OpenAthens details.