The classical authors associate the insanity with delusions, without delusions there was not insanity. This axiom has changed nowadays, and it's also accepted that insanity can exist without delusions.

We aim to know and describe which factors are involved in the development of the delusion. Use these conclusions to drive the patient to the comprehension and acceptance of the reality.

(a) Unravel the mechanism of delusion, (b) seek the causes, (c) find out an explanation about the origin and development of the delusional thematic.

Clinical biographic review, carried on in 2 steps: (a) review the delusions store in the Hermanas Hospitalarias Spanish hospitals (17 centres), (b) choose one of them, (c) use the inductive method for analyzing the details and for making conclusions in order to be apply in the delusional process.

(a) Understand the internal dynamic of delusion and how the delusion becomes the main axis of the patient life. (b) The patient finds on the delusion a life motive, which did not exist before.

Paraphrasing Dr.Castilla del Pino, “the delusion is a necessary mistake”. From the emotional point of view, it can be said “the delusion is a cry of a captured heart”.

The authors have not supplied their declaration of competing interest.