La mythomanie constitutionnelle pose des problèmes diagnostique, étiopathogénique et médicolégal pour le médecin. Nous avons discuté ces aspects à partir de l’analyse d’une observation. Il s’agissait d’un homme de 43ans, qui a été examiné dans le cadre d’une expertise pénale à la suite de l’émission de chèques sans provision. À l’examen, il prétendait être, à la fois, médecin et avocat. Il a été poursuivi dans plusieurs des affaires d’escroquerie. Du point de vue psychodynamique, la mythomanie constitutionnelle entrerait dans le cadre des états limites. Elle reflète une grande faille narcissique. La théorie de Maleval pourrait également être transposée chez notre malade. Enfin, l’attitude de notre patient, comme celles de certains psychotiques, pourrait cadrer avec la création d’un mythe personnel afin de réduire la fragmentation du Moi. Sur le plan médicolégal, on pourrait a priori postuler que le mythomane perçoit suffisamment la réalité pour être considéré comme lucide au sens légal. En fait, il maîtrise avec peine la totalité de ses intentions, étant guidé par un automatisme irrépressible qui fait de la mythomanie une maladie « grave » handicapante dont la première victime est le sujet lui-même. Aucune mesure n’est à même de l’empêcher d’enfreindre la loi, sauf, peut-être, un contrôle administratif permanent, ce qui n’est pas sans poser de problèmes pratiques et éthiques.

Constitutional mythomania presents several diagnostic, aetiopathogenic and forensic problems for the doctor. We have discussed these aspects through the analysis of a case report.

The case report relates to a 43 year-old man, who was subjected to a penal expertise following the emission of cheques without provision. During the examination, he pretended being both a doctor and a lawyer at the same time. He was in charge, among other things, of sale contracts dealing sometimes with high value transactions, obviously without following the required legal procedure. He was pursued subsequently for many other affairs of swindle. Data collected from his medical file indicated that he was the only boy of his family. Since his father had suffered from psychotic episodes, his grandfather had reared him; which he did it in a strictly religious way. He spent his childhood isolated. He was 15 years old when his grandfather died. He had then expressed religious and megalomaniac ideas that had motivated psychiatric management. Later on, he expressed imaginative ideas evoking unsystematized delusion (he pretended to have made a trip to America and to have seen a fish flying and turning into a woman).

From a psychodynamic point of view, constitutional mythomania is considered as a borderline personality. It reflects an important narcissisic cleavage. The deceitfulness of the mythomaniac allows him to keep in touch with reality and to avoid mental disintegration. The recognition, by others, of these delusions allows the mythomaniac to have access to his proper level of existence. For a while, to the experts our patient appeared to be suffering from schizophrenia. Therefore, we can apply the Maleval theory to him, which identifies four periods as delusion structuring levels in psychosis : P0 (consequence of the phallic signification deficiency, it includes anxiety, annihilation, perplexity, interrogative attitude), P1 (stage of paranoid delusion), P2 (stage of paranoiac delusion) and P3 (ambitious stage evoking paraphrenia and squaring with mythomaniac behaviour). According to the Maleval theory, our patient would have experimented a repetitive cycle: he tried to escape instable and anxious positions (P0, P1) by committing sacrificial acting out (offence), or by reaching stable positions which are P2 and P3. The mythomaniac behaviour would appear during the latest period. The delusional decompensation would indicate a return to the first two periods. On the other hand, the personal myth might be seen as the result of the failure of the assimilation of actual experiences. Several psychoanalysts consider the use of myths by some psychotics as an attempt to reduce their ego disintegration. The mythomaniac may create his own myth in order to reduce the psychotic anxiety. The personal myth does not represent the pain of the patient but his remedy against his disorders. Therefore, identifying a personal myth may help the psychotic to turn his delusion into supportable logic of life. Myth may also be used in less deep pathologies such as borderline context, where it dominates the clinical picture.

On the forensic level, we could a priori postulate that the mythomaniac sufficiently perceives reality to be considered as lucid. In fact, he hardly masters the totality of his intentions, being guided by an irrepressible mechanism that makes mythomania a “serious” and handicapping illness; its prima victim being the patient him/herself. No measures could actually prevent the latter from infringing the law, except, perhaps, a permanent administrative control; but this would not be without practical and ethical problems.