Hysterical psychosis has never been part of the standard nomenclature. Janet postulated that a psychosis could be considered hysterical if its dissociative nature could be established. Breuer and Freud emphasized the traumatic origins and oneiroid form of the disorder. Hollender and Hirsch focused mainly on descriptive features: the dramatic onset, the temporal relation to an upsetting event, the short duration and the preponderance of females with histrionic behavior.

To demonstrate the traumatic origins and distinct features of hysterical psychosis.

A clinical case was followed and reviewed.

A 48-year-old female presented acutely with disorganized behavior, negativism, loosening of associations, delusions of demonic influence and a fluctuating level of consciousness. Symptom onset was temporally related to severe family stressors. A complete medical evaluation ruled out the presence of an underlying organic factor. Dissociative conversion disorder was chosen as our working diagnosis. Rapid clinical response was achieved on low dose paliperidone. After the abatement of symptoms, our patient provided a comprehensive history of her experience, describing an oneiroid state in which she transiently submerged in vivid fantasies based upon past traumatic life events. Pharmacotherapy was gradually withdrawn and psychodynamic psychotherapy was introduced as a means to help her abreact the past traumata and integrate them into a cohesive self.

This case supports Janet's formulation of hysterical psychosis and demonstrates the usefulness of the dissociative component in forming a diagnostic impression and treatment approach. It also underlines the need of distinctly classifying this clinical entity among dissociative disorders.