Link between cognitive polygenic risk scores and clinical progression after a first-psychotic episode

Background Clinical intervention in early stages of psychotic disorders is crucial for the prevention of severe symptomatology trajectories and poor outcomes. Genetic variability is studied as a promising modulator of prognosis, thus novel approaches considering the polygenic nature of these complex phenotypes are required to unravel the mechanisms underlying the early progression of the disorder. Methods The sample comprised of 233 first-episode psychosis (FEP) subjects with clinical and cognitive data assessed periodically for a 2-year period and 150 matched controls. Polygenic risk scores (PRSs) for schizophrenia, bipolar disorder, depression, education attainment and cognitive performance were used to assess the genetic risk of FEP and to characterize their association with premorbid, baseline and progression of clinical and cognitive status. Results Schizophrenia, bipolar disorder and cognitive performance PRSs were associated with an increased risk of FEP [false discovery rate (FDR) ⩽ 0.027]. In FEP patients, increased cognitive PRSs were found for FEP patients with more cognitive reserve (FDR ⩽ 0.037). PRSs reflecting a genetic liability for improved cognition were associated with a better course of symptoms, functionality and working memory (FDR ⩽ 0.039). Moreover, the PRS of depression was associated with a worse trajectory of the executive function and the general cognitive status (FDR ⩽ 0.001). Conclusions Our study provides novel evidence of the polygenic bases of psychosis and its clinical manifestation in its first stage. The consistent effect of cognitive PRSs on the early clinical progression suggests that the mechanisms underlying the psychotic episode and its severity could be partially independent

Estimulación cerebral profunda en esquizofrenia resistente

La esquizofrènia és un trastorn psiquiàtric altament incapacitant, amb un 20-30% dels pacients que no responen als tractamnets disponibles actualment. Les tècniques de neuroimatge més recents han sigut capaces d'avançar en el coneixement de la fisiopatologia del trastorn, implicant el sistema dopaminèrgic i glutamatèrgic de diferents àrees del circuit que connecta el còrtex amb els ganglis basals. L'evidència més robusta apunta al nucli estriat com el principal protagonista de la disregulació d'aquests sistemes de neurotransmisió, que per les seves connexions recíproques amb el còrtex i el tronc de l'encèfal, produiria una alteració dels diversos circuits cortico-estriatals que podrien justificar els símptomes positius, negatius i cognitius en la esquizofrènia. Altres trastorns neuropsquiàtrics resistents al tractament convencional, com el trastorn obsessiu-comulsiu o el trastorn depressiu major, que també han mostrat alteracions d'aquest circuit, han estat tributaris de beneficiar-se de noves tècniques de neuromodulació, com la estimulació cerebral profunda (ECP). Per tant, es planteja que la ECP també seria una opció de tractament vàlida per pacients que pateixen una esquizofrènia resistent al tractmaent. A aquesta tesi es presenta el primer assaig clínic aleatoritzat i creuat al que es van incloure vuit pacients amb esquizofrènia resistent al tractament, als quals es va aleatoritzar a una de les dues dianes terapèutiques proposades: el còrtex prefrontal medial, -àrea subgenual del còrtex cingulat anterior Cg25 (sgACC)- o l'estructura límbica que forma part de l'estriat ventral, en nucli accumbens (NAc). Els resultats demostren que el 50% dels pacients intervinguts presenten una milloria de la clínica psicòtica tant positiva, con negativa i general, mesurada amb la variable principal d'eficàcia PANSS. Els resultats apuntaríen a una major eficàcia a aquells pacients estimulats al NAc que al sgACC. A més, la estimulació amb ECP comporta canvis en l'activitat metabòlica cerebral mesurada amb PET, tant al mateix lloc d'estimulacio com a àreas allunyades de la inserció dels electrodes. Els canvis metabòlics observats després de la ECP no responen a un patró homogeni, ni tan sols en aquells pacients intervinguts en la mateixa diana d'inserció de l'electrode. Tot i així, hi hauria una tendència en els pacients estimulats al NAc, que mostra un patró d'activació metabòlica a zones determinades del circuit cortico-estriatal-tàlam-cortical. Això confirmaria la seva implicació en la fisiopatologia de la malaltia i la seva potencial capacitat de neuromodulació amb ECP. Els resultats presenstats a aquesta tesi doctoral obren un nou horitzó de tractament per a alguns d'aquells pacients diagnosticats d'esquizofrènia que no han trobat benefici amb els tractaments disponibles actualment.La esquizofrenia es un trastorno psiquiátrico altamente incapacitante, con un 20-30% de pacientes que no responden a los tratamientos disponibles actualmente. Las técnicas de neuroimagen más recientes han sido capaces de avanzar en el conocimiento de la fisiopatología del trastorno, implicando el sistema dopaminérgico y glutamatérgico de diversas áreas del circuito que conecta el córtex con los ganglios basales. La evidencia más robusta apunta al núcleo estriado como el principal protagonista de la disregulación de estos sistemas de neurotransmisión, que por sus conexiones recíprocas con el córtex y el tronco del encéfalo, produciría una alteración de los diversos circuitos cortico-estriatales que podrían justificar los síntomas positivos, negativos y cognitivos en la esquizofrenia. Otros trastornos neuropsiquiátricos resistentes al tratamiento convencional, principalmente el trastorno oobsesivo-compulsivo o el trastorno depresivo mayor, que también han mostrado alteraciones en este circuito, han sido tributarios de beneficiarse de nuevas técnicas de neuromodulación, como la estimulación cerebral profunda (ECP). Por tanto, se plantea que la ECP también sería una opción de tratamiento válida para aquellos pacientes que padecen una esquizofrenia resistente al tratamiento. En esta tesis se presenta el primer ensayo clínico aleatorizado y cruzado en el que se incluyeron ocho pacientes con esquizofrenia resistente al tratamiento, a los cuales se aleatorizó a uno de los dos 'targets' propuestos: córtex prefrontal medial, -área subgenual del córtex cingulado anterior Cg25 (sgACC)- o la estructura límbica que forma parte del estriado ventral, el núcleo accumbens (NAc). Los resultados demuestran que el 50% de los pacientes intervenidos presentan una mejoría de la clínica psicótica tanto positiva, negativa como general, medida con la variable principal de eficacia PANSS. Los resultados apuntarían a una mayor eficacia de aquellos pacientes estimulados en NAc que en sgACC. Además la estimulación con ECP conlleva cambios en la actividad metabólica cerebral medida con PET, tanto en el mismo lugar de estimulación como en lugares alejados de la inserción de los electrodos. Los cambios metabólicos observados tras la ECP no responden a un patrón homogéneo, ni siquiera en aquellos pacientes intervenidos en la misma diana de inserción del electrodo. Aun así, habría una tendencia en aquellos pacientes estimulados en NAc, que muestra un patrón de activación metabólica en zonas determinadas del circuito cortico-estriatal-tálamo-cortical. Esto confirmaría su implicación en la fisiopatología de la enfermedad y su potencial capacidad de neuromodulación con ECP. Los resultados presentados en esta tesis doctoral abren un nuevo horizonte de tratamiento para algunos de aquellos pacientes diagnosticados de esquizofrenia que no han encontrado beneficio con los tratamientos disponibles actualmente.Schizophrenia is a highly disabling disorder, with a 20-30% of patients who do not respond to available treatments. Novel neuroimaging techniques have been able to improve knowledge of the pathophysiology of the disorder, involving dopaminergic and glutamatergic systems of several brain areas connecting the cortex with basal ganglia. The most robust evidence points towards the striatum to have a main rol in the dysregulation of those neurotransmission systems. Its reciprocal connections with the cortex and the brainstem, would lead to alterations in cortico-striatal circuits, that would justify the positive, negative and cognitive symptoms in schizophrenia. Other neuropsychiatric disorders, as the obsessive-compulsive disorder or the major depressive disorder, have shown impairments in the same circuitry and improvements with novel neuromodulation techiques, as the deep brain stmulation (DBS). Then, ECP may be a valid treatment option for treatment resistant schizophrenia. In this thesis is presented the first randomized controlled trial including eight patients with treatment resistant schizophrenia, who were randomized to one of the two proposed targets: the subgenual anterior cingulate cortex (sgACC), in the medial prefrontal cortex, or the the nucleus accumbens (NAc). The findings show that 50% of patients improved in their psychotic positive, negative and general symptoms, measured with PANSS scale. The results suggest a higher efficacy in those patients stimulated at NAc. Additionally, DBS generate PET metabolic brain changes in the area around the electrode and also in distal areas. These metabolic changes do not show an homogeneous pattern, even in those patients intervened in the same target. However, patients with NAc-DBS show a metabolic activation pattern in several areas of the cortico-striatal circuit. This would confirm its implication in the pathophysiology of the disorder and its potential capacity for neuromodulation with DBS. The results presented in this doctoral thesis open a new treatment horizon for some of those patients with schizophrenia that do no respond to current available treatment.Universitat Autònoma de Barcelona. Programa de Doctorat en Psiquiatri

Link between cognitive polygenic risk scores and clinical progression after a first-psychotic episode

Clinical intervention in early stages of psychotic disorders is crucial for the prevention of severe symptomatology trajectories and poor outcomes. Genetic variability is studied as a promising modulator of prognosis, thus novel approaches considering the polygenic nature of these complex phenotypes are required to unravel the mechanisms underlying the early progression of the disorder. The sample comprised of 233 first-episode psychosis (FEP) subjects with clinical and cognitive data assessed periodically for a 2-year period and 150 matched controls. Polygenic risk scores (PRSs) for schizophrenia, bipolar disorder, depression, education attainment and cognitive performance were used to assess the genetic risk of FEP and to characterize their association with premorbid, baseline and progression of clinical and cognitive status. Schizophrenia, bipolar disorder and cognitive performance PRSs were associated with an increased risk of FEP [false discovery rate (FDR) ⩽ 0.027]. In FEP patients, increased cognitive PRSs were found for FEP patients with more cognitive reserve (FDR ⩽ 0.037). PRSs reflecting a genetic liability for improved cognition were associated with a better course of symptoms, functionality and working memory (FDR ⩽ 0.039). Moreover, the PRS of depression was associated with a worse trajectory of the executive function and the general cognitive status (FDR ⩽ 0.001). Our study provides novel evidence of the polygenic bases of psychosis and its clinical manifestation in its first stage. The consistent effect of cognitive PRSs on the early clinical progression suggests that the mechanisms underlying the psychotic episode and its severity could be partially independent

Exploration of cannabis use and polygenic risk scores on the psychotic symptom progression of a FEP cohort

Cannabis use is highly prevalent in first-episode psychosis (FEP) and plays a critical role in its onset and prognosis, but the genetic underpinnings promoting both conditions are poorly understood. Current treatment strategies for cannabis cessation in FEP are clearly inefficacious. Here, we aimed to characterize the association between cannabis-related polygenic risk scores (PRS) on cannabis use and clinical course after a FEP. A cohort of 249 FEP individuals were evaluated during 12 months. Symptom severity was measured with the Positive and Negative Severity Scale and cannabis use with the EuropASI scale. Individual PRS for lifetime cannabis initiation (PRSCI) and cannabis use disorder (PRSCUD) were constructed. Current cannabis use was associated with increased positive symptoms. Cannabis initiation at younger ages conditioned the 12-month symptom progression. FEP patients with higher cannabis PRSCUD reported increased baseline cannabis use. PRSCI was associated with the course of negative and general symptomatology over follow-up. Cannabis use and symptom progression after a FEP were modulated by cannabis PRS, suggesting that lifetime initiation and use disorders may have partially independent genetic factors. These exploratory results may be the first step to identify those FEP patients more vulnerable to cannabis use and worse outcomes to ultimately develop tailored treatments