Diurnal variation in Cotard's syndrome (copresent with Capgras delusion) following traumatic brain injury

Objective: The aim of this paper is to document regular nocturnal intensification of delusional nihilistic and persecutory ideas (Cotard delusion) linked with extreme depersonalisation and hypervivid dreaming. Clinical Picture: A 17-year-old man presented with Cotard and Capgras delusions after sustaining multiple cognitive impairments secondary to traumatic brain injury. Treatment and outcome: Delusional ideation fully resolved within 14 days of commencement of olanzapine 5 mg daily. Conclusion: This patient's experience of perceptual abnormalities and impairments in meta-abilities related to self-monitoring and critical inferencing lends support to multicomponent sensory processing accounts of brain injury related, content-specific delusional syndromes.