RESUMEN
OBJECTIVE: The authors investigated the associations between polygenic liability and progression to bipolar disorder or psychotic disorders among individuals diagnosed with unipolar depression in early life. METHODS: A cohort comprising 16,949 individuals (69% female, 10-35 years old at the first depression diagnosis) from the iPSYCH Danish case-cohort study (iPSYCH2012) who were diagnosed with depression in Danish psychiatric hospitals from 1994 to 2016 was examined. Polygenic risk scores (PRSs) for major depression, bipolar disorder, and schizophrenia were generated using the most recent results from the Psychiatric Genomics Consortium. Hazard ratios for each disorder-specific PRS were estimated using Cox regressions with adjustment for the other two PRSs. Absolute risk of progression was estimated using the cumulative hazard. RESULTS: Patients were followed for up to 21 years (median=7 years, interquartile range, 5-10 years). The absolute risks of progression to bipolar disorder and psychotic disorders were 7.3% and 13.8%, respectively. After mutual adjustment for the other PRSs, only the PRS for bipolar disorder predicted progression to bipolar disorder (adjusted hazard ratio for a one-standard-deviation increase in PRS=1.11, 95% CI=1.03, 1.21), and only the PRS for schizophrenia predicted progression to psychotic disorders (adjusted hazard ratio=1.10, 95% CI=1.04, 1.16). After adjusting for PRSs, parental history still strongly predicted progression to bipolar disorder (adjusted hazard ratio=5.02, 95% CI=3.53, 7.14) and psychotic disorders (adjusted hazard ratio=1.63, 95% CI=1.30, 2.06). CONCLUSIONS: PRSs for bipolar disorder and schizophrenia are associated with risk for progression to bipolar disorder or psychotic disorders, respectively, among individuals diagnosed with depression; however, the effects are small compared with parental history, particularly for bipolar disorder.
Asunto(s)
Trastorno Bipolar/genética , Trastorno Depresivo/genética , Herencia Multifactorial/genética , Trastornos Psicóticos/genética , Adolescente , Adulto , Niño , Dinamarca , Progresión de la Enfermedad , Femenino , Técnicas de Genotipaje , Humanos , Masculino , Factores de Riesgo , Esquizofrenia/genética , Adulto JovenRESUMEN
22q11.2 deletion syndrome (22q11.2DS) is one of the most common copy number variants and confers a markedly increased risk for schizophrenia. As such, 22q11.2DS is a homogeneous genetic liability model which enables studies to delineate functional abnormalities that may precede disease onset. Mismatch negativity (MMN), a brain marker of change detection, is reduced in people with schizophrenia compared to healthy controls. Using dynamic causal modelling (DCM), previous studies showed that top-down effective connectivity linking the frontal and temporal cortex is reduced in schizophrenia relative to healthy controls in MMN tasks. In the search for early risk-markers for schizophrenia we investigated the neural basis of change detection in a group with 22q11.2DS. We recorded high-density EEG from 19 young non-psychotic 22q11.2 deletion carriers, as well as from 27 healthy non-carriers with comparable age distribution and sex ratio, while they listened to a sequence of sounds arranged in a roving oddball paradigm. Despite finding no significant reduction in the MMN responses, whole-scalp spatiotemporal analysis of responses to the tones revealed a greater fronto-temporal N1 component in the 22q11.2 deletion carriers. DCM showed reduced intrinsic connection within right primary auditory cortex as well as in the top-down, connection from the right inferior frontal gyrus to right superior temporal gyrus for 22q11.2 deletion carriers although not surviving correction for multiple comparison. We discuss these findings in terms of reduced adaptation and a general increased sensitivity to tones in 22q11.2DS.
Asunto(s)
Percepción Auditiva/fisiología , Síndrome de DiGeorge/fisiopatología , Potenciales Evocados Auditivos/fisiología , Corteza Prefrontal/fisiopatología , Lóbulo Temporal/fisiopatología , Adolescente , Adulto , Corteza Auditiva/fisiopatología , Niño , Electroencefalografía , Femenino , Heterocigoto , Humanos , Masculino , Modelos Teóricos , Análisis Espacio-Temporal , Adulto JovenRESUMEN
Abnormality in neurodevelopment is one of the most robust hypotheses on the etiology of schizophrenia and has found substantial support from brain imaging and genetic studies. Neurodevelopmental processes involve several signaling pathways, including the Notch, but little is known at present regarding their possible involvement in schizophrenia. In the present study we investigated the link of non-synonymous variants of five genes of the Notch pathway (NOTCH2, NOTCH3, JAGGED2, ASCL1 and NUMBL) to schizophrenia in a group of 200 Brazilian patients and 200-paired controls. Also, we replicated the association of the NUMBL variant, our most promising finding, in an unrelated set of 684 Danish patients and controls. When the Brazilian and Danish cohorts were merged, a total of 1084 subjects, we found the allele 18 CAG of NUMBL (p=0.003, x2=8.88, OR=1.30, 95% CI 1.09-1.56) as well as the 18/18 CAG genotype (p=0.002, x2=9.46, OR=1.46, 95% CI 1.15-1.87) to be associated with schizophrenia. The consistency of this finding in two independent and unrelated populations reinforces the veracity of this association.