Centre Hospitalier Universitaire de Nimes

The transition between adolescence and adulthood (generally defined as ages 18 to 25) is a key developmental window for narrative identity and psychotic disorders. Narrative identity is positively associated with mental health. This study will focus on the acquisition of narrative identity in First Episode Psychosis (FEP) and its impact on multidimensional subjective well-being.
The study authors hypothesize that levels of the various components of narrative identity would be lower in the FEP group than in the "chronic" and control groups, and in the "chronic" group versus control group. Given the paucity contradictory nature of the published literature, no hypotheses have been formulated regarding these correlations and predictions. Instead, this study will remain an exploratory analysis in the different samples.

Psychogenic non-epileptic seizures (PNES) are functional paroxysmal motor disorders that may be clinically suggestive of epilepsy but are not associated with the electroencephysiological and electroencephalographic changes of epilepsy. Thus, hyper-connectivity of the regions of the default mode network (DMN) linked to executive control could be involved in the impairment of cognitive control capacities in patients suffering from PNES. Also, the HYCORE study (NCT02329626), showed that dysregulation of frontal regions involved in attentional and emotional regulation is correlated with motor symptoms in patients with functional neurological disorders.
The researchers of this study hypothesized that psilocybin would improve cognitive control in patients with PNES.

The study hypothesis is that the antidepressant effect of psilocybin is mediated by a normalization of the functioning of the positive valence system. Depressive states, especially moderate to severe depressions that associate a certain level of anhedonia, produce an overvaluation of the cost of efforts and an infra-evaluation of the possible rewards derived from an action. Psilocybin would reduce anhedonia and the cost of efforts, facilitating the anticipation of reward. Thus, the antidepressant effect of psilocybin would be mediated by a greater anticipation of rewards (reduction of anhedonia) and a more optimistic estimation of the results of efforts (increase in motivation). Psilocybin-induced changes in the positive valence system will be observable on brain MRI images, particularly in the effort evaluation circuits: basolateral amygdala, dorsal anterior cingulate cortex, ventral pallidum, ventral striatum (VS), ventral tegmental area (VTA). The mesolimbic circuit (VS, VTA) is the anatomical substrate of anticipation of rewarding stimuli (food, sex, drugs). The amygdala also fulfills an associative function between environmental cues and rewarding stimuli. Structural and functional alterations in this circuit are associated with depressive symptoms such as anhedonia or distortions in the perception and memories of rewards. This hypothesis will be tested on a population of patients with moderate or severe depressive symptoms who meet the criteria for TRD.