Propriété égolytique des psychédéliques et intérêts dans le traitement de la dépression

Approximately a third of depressive patients doesn’t respond to classical treatments and never experiences remission, justifying the need for novel therapeutic approaches. Research on the effect of psychedelics on consciousness and their therapeutic use is currently re-exploding. New data confirm that the psychedelic experience with psychological support is well-tolerated and diminishes immediately and durably the symptoms associated with anxiety and depression. This article gathers neurophysiological and psychological arguments which posit that psychedelics’ effect on depressive symptoms is due to their egolytic properties. Ego roles are adaptive by sustaining a sense of personal unity, continuity over time, and by guiding behavior in a coherent manner. However, ego dysfunctions can lead to cognitive biases and schemas involved in several psychopathological conditions, such as depression. Therefore, ego is a cornerstone of psychotherapy. It is proposed that default mode network functions and organization are somewhat consistent with the description of the ego. In major depression, hyperconnectivity of the default mode network's brain areas causes ego-focused and stereotyped symptoms such as ruminations and excessive tendency to self-judgment. On the contrary, psychedelics disrupt the functional connectivity of brain areas belonging to the default mode network, causing ego dissolution and releasing consciousness from its constrains. As a result, a flow of supplementary bottom-up limbic information can reach consciousness and the subject experiences a mystical sense of connectedness with what is usually seen as external. Even if the psychedelic state is transitory, its benefits on depressive symptoms persist over time. The reason is that the psychedelic experience leads to phenomena of insights and long-term perspective shifts. Thus, psychedelic-assisted psychotherapies appear as a promising option in the treatment of treatment-resistant depressions. Research on the effects of psychedelics in human is an exciting and promising field, which might continue to yield interesting results regarding their psychotherapeutic potentials and the link between brain and consciousness.