The delusional dimension of anorexia nervosa: phenomenological, neurobiological and clinical perspectives

Background Delusional characteristics have been largely ignored in patients suffering from anorexia nervosa (AN). Objectives To review the literature on delusional features in AN from phenomenological, neurobiological, and clinical viewpoints. Methods Data were obtained through searches of Medline, PubMed, SciELO and Cochrane Library. Results Distorted beliefs in AN may range from an overvalued idea to an overt delusion, involving affective, personality and/or psychotic disorders. Studies confirm alterations in monoaminergic systems. It has also been seen a decreased integration of visual/proprioceptive information, and alterations in neural networks involved in body processing. It is known that body image distortion may present “delusional proportions” as a consequence of great concern about body. Concomitantly, “embodied defence hypothesis” has been proposed. Restrictive AN exhibits higher levels of delusionality, and a particular delusional type of AN has been suggested, associated with a worse long-term outcome. Low doses of atypical antipsychotics are recommended combined with cognitive techniques. Discussion Delusional thinking in AN is likely a dynamic and dimensional phenomenon that can vary, both in nature and/or severity, whereas high insight levels, before and after refeeding, result in positive outcomes. Neurobiological research on this topic must be encouraged, since clinical and phenomenological approaches are comparatively more frequently reported

The delusional dimension of anorexia nervosa: phenomenological, neurobiological and clinical perspectives

Background: Delusional characteristics have been largely ignored in patients suffering from anorexia nervosa ( AN). Objectives: To review the literature on delusional features in AN from phenomenological, neurobiological, and clinical viewpoints. Methods: Data were obtained through searches of Medline, PubMed, SciELO and Cochrane Library. Results: Distorted beliefs in AN may range from an overvalued idea to an overt delusion, involving affective, personality and/or psychotic disorders. Studies confirm alterations in monoaminergic systems. It has also been seen a decreased integration of visual/proprioceptive information, and alterations in neural networks involved in body processing. It is known that body image distortion may present "delusional proportions" as a consequence of great concern about body. Concomitantly, "embodied defence hypothesis" has been proposed. Restrictive AN exhibits higher levels of delusionality, and a particular delusional type of AN has been suggested, associated with a worse long-term outcome. Low doses of atypical antipsychotics are recommended combined with cognitive techniques. Discussion: Delusional thinking in AN is likely a dynamic and dimensional phenomenon that can vary, both in nature and/or severity, whereas high insight levels, before and after refeeding, result in positive outcomes. Neurobiological research on this topic must be encouraged, since clinical and phenomenological approaches are comparatively more frequently reported

Towards a neurobiological understanding of alexithymia

Resumen Si bien la literatura especializada sobre la etiología de la alexitimia es controvertida, la investigación neurobiológica sobre el fenómeno ha demostrado importantes avances. El objetivo de esta revisión es analizar la evidencia disponible en relación a las bases neurofisiológicas de la alexitimia. Se realizó una revisión exhaustiva de artículos disponibles en MEDLINE/PubMed, EBSCO y SciELO. Inicialmente, se vinculó a la alexitimia con una conexión cerebral interhemisférica reducida. Desde la perspectiva traumática infantil, la corteza prefrontal derecha y la red neuronal por defecto experimentarían alteraciones, primero hipermetabólicas (desregulación dopaminérgica y glutamatérgica) y luego hipometabólicas-disociativas (desregulación serotoninérgica y opioide), resultando en una consciencia interoceptiva y emocional distorsionada. Las neuronas espejo son el sustrato neurobiológico fundamental de la teoría de la mente y la cognición social, intrínsecamente vinculadas con la alexitimia, involucrando cortezas como la parietal, la temporal, la premotora, la cingulada y el giro frontal inferior. Otras estructuras involucradas son amígdala (expresión facial y reactividad emocional), ínsula (interocepción, integración emocional y empatía) y cerebelo (cerebelo límbico y consciencia somatosensorial). La genética molecular ha detectado polimorfismos en el gen del transportador de serotonina, en los genes de las enzimas del metabolismo dopaminérgico y del factor neurotrófico derivado del cerebro, mientras que el rol de la oxitocina es controvertido. En conclusión, numerosos estudios demuestran contundentemente la existencia de una neurobiología subyacente a la alexitimia. Sin embargo, la investigación es aún poco concluyente y debe considerar los factores ambientales, traumáticos, sociales y psicológicos que contribuyen al origen del fenómeno

Brief psychosis induced by methylphenidate in a child with attention deficit disorder: a case report and literature review

Resumen La psicosis inducida por metilfenidato ha sido escasamente estudiada debido a los problemas bioéticos y neurobiológicos relacionados con su investigación. Si bien evidenciaría una vulnerabilidad a largo plazo para el desarrollo de un trastorno psiquiátrico mayor, no hay consenso sobre su valor predictivo en la población infanto-juvenil, mientras que su origen es incierto. Se ha sugerido que los mayores niveles de dopamina en ciertas zonas cerebrales y el antecedente familiar de algunos trastornos mentales, aumentaría el riesgo de presentar psicosis secundaria a psicoestimulantes. Presentamos el caso de un niño de nueve años de edad, con diagnóstico de trastorno por déficit de atención comórbido a una oposición desafiante, que durante el tratamiento con metilfenidato presentó alucinaciones visuales y auditivas e ideas deliriosas de daño que cedieron con la suspensión del fármaco. Se discuten los principales aspectos relacionados con el origen, la causalidad, el manejo y el pronóstico de la psicosis inducida por psicoestimulantes

Proteostasis and Mitochondrial Role on Psychiatric and Neurodegenerative Disorders: Current Perspectives

Proteostasis involves processes that are fundamental for neural viability. Thus, protein misfolding and the formation of toxic aggregates at neural level, secondary to dysregulation of the conservative mechanisms of proteostasis, are associated with several neuropsychiatric conditions. It has been observed that impaired mitochondrial function due to a dysregulated proteostasis control system, that is, ubiquitin-proteasome system and chaperones, could also have effects on neurodegenerative disorders. We aimed to critically analyze the available findings regarding the neurobiological implications of proteostasis on the development of neurodegenerative and psychiatric diseases, considering the mitochondrial role. Proteostasis alterations in the prefrontal cortex implicate proteome instability and accumulation of misfolded proteins. Altered mitochondrial dynamics, especially in proteostasis processes, could impede the normal compensatory mechanisms against cell damage. Thereby, altered mitochondrial functions on regulatory modulation of dendritic development, neuroinflammation, and respiratory function may underlie the development of some psychiatric conditions, such as schizophrenia, being influenced by a genetic background. It is expected that with the increasing evidence about proteostasis in neuropsychiatric disorders, new therapeutic alternatives will emerge