[The delusion of world catastrophe. Is this classic symptom still relevant today?].

Background: The delusion of world catastrophe was conceptualised by classic authors such as Jaspers and Conrad as a specific expression of acute psychosis that deserved special attention in psychiatric diagnosis. We need to find out whether this approach is still relevant today.

Aim: To provide an overview of the literature about the delusion of world catastrophe.

Method: The literature was searched and historical literature was also consulted.

Results: A patient's delusion of world catastrophe often begins with a phase known as the 'Wahnstimmung' which may be accompanied by subtle positive disorders of perception. This is followed by frank psychosis, with hallucinations, formal thought disorders, and, in exceptional cases, can lead to suicidality and/or homicidality. Prevalence rates derived from populations of patients diagnosed with a schizophrenia spectrum disorder vary from 1% to 8%, with a single outlier of 63.5%. Wetzel was the first to conceptualise the delusion of world catastrophe as an attempt of the brain to make sense of a world on which it had lost its grip due to the psychotic process. The link Wetzel established between subtle disorders of perception and possible organic causes is still relevant today.

Conclusion: Patients who are beginning to have delusions of world catastrophe deserve not only to get an early diagnosis of the neurobiological correlates of their perceptual disorders, but also to receive adequate treatment for their psychosis.