Young Offspring at Genetic Risk of Adult Psychoses: The Form of the Trajectory of IQ or Memory May Orient to the Right Dysfunction at the Right Time

Abstract

ObjectiveNeurocognitive dysfunctions analogous to those of adult patients have been detected in children at risk of schizophrenia and bipolar disorder. This led to the following developmental question: Do IQ and memory impairments exhibit different developmental courses from childhood to young adulthood in terms of stability or fluctuations?MethodsIn a high risk sample, we used a step by step sampling approach to narrow-down the early disease mechanisms. Upstream, we started with a 20-year follow-up of 48 densely affected multigenerational kindreds, including 1500 clinically characterized adult members. We then identified 400 adult members affected by a DSM-IV schizophrenia or bipolar disorder. Downstream, we finally focused on 65 offspring (of an affected parent) aged 7 to 22, who were administered a neuropsychological battery. We then constructed cross-sectional trajectories that were compared to those of controls.ResultsThe childhood IQ deficit displayed a stability until young adulthood. The delay in visual memory exhibited a non-linear two-stage trajectory: a lagging period during childhood followed by a recuperation period from adolescence until adulthood, as supported by a significant Group x Age Periods interaction. No data suggested deterioration between 7 and 22.ConclusionIn these offspring at genetic risk, the developmental trajectory of global IQ impairment may not apply to specific domains of cognition such as episodic memory. Different cognitive dysfunctions would mark different developmental courses. The shape of the trajectories might itself have a meaning and provide empirical leads for targeting the right dysfunction at the right time in future prevention research.

Childhood abuse and neglect may induce deficits in cognitive precursors of psychosis in high-risk children

“…49 Correspondingly, we previously reported a dynamic changing course of visual memory impairments from childhood until adulthood that contrasted with the more stable or static course of verbal memory in high-risk offspring. 50 Our observation that exposure in the young offspring of parents with schizophrenia or BD would induce similar cognitive dysfunctions is consistent with observations that these 2 adult disorders share many genetic, phenotypic and endophenotypic characteristics 15,51 and that the young offspring of parents with schizophrenia or BD display common cognitive impairments. 9,16,27 The offspring of parents with schizophrenia or BD are likely to carry a genetic vulnerability expressed in greater biological sensitivity to stress, 52 thus sensitizing them to abuse and neglect.…”

“…Third, our instrument did not allow us to assess how much of the exposure to abuse or neglect was subjectively traumatic to the child -a factor known to be associated with outcome. 59 Fourth, although our sample size of 66 participants was rather large in comparison to most prior studies of young high-risk offspring, 50,60 a larger sample would be needed to eliminate type 2 errors and to clarify potential specific effects of different types of trauma. Fifth, our research highlighted an association between maltreatment in childhood/adolescence and performance in cognitive precursors of psychosis.…”

Revisiting visual dysfunctions in schizophrenia from the retina to the cortical cells: A manifestation of defective neurodevelopment

“…An early neurodevelopmental origin might explain such an alteration of the whole visual system, congruent with the neurodevelopmental theory underlying schizophrenia (Fatemi & Folsom, 2009;Lewis & Levitt, 2002;Maziade et al, 2011;Rapoport et al, 2005). The visual nervous system originates mainly from the neuroectoderm.…”

Neuropsychological Profile of Children, Adolescents and Adults Experiencing Maltreatment: A Meta-analysis

“…These young people also demonstrate cognitive deficits relative to youth that have not been maltreated (Beers & De Bellis, 2002). Specific cognitive impairments at a specific time in development could potentially shape the cognitive trajectory of young people and adversely affect their mental health (Maziade et al, 2011). Cognitive deficits in victims of maltreatment may result from chronic stress caused by abuse.…”