Dataset Information

Course of Cognitive Development From Infancy to Early Adulthood in the Psychosis Spectrum.

ABSTRACT:

Importance

Most patients with psychotic disorders experience severe cognitive impairment, but the onset and course of this impairment remain unclear. Moreover, the course of cognitive functions in other psychiatric conditions remains largely unexamined.

Objective

To chart the course of general and specific cognitive functions in individuals with psychotic disorders, psychotic experiences, and depression.

Design, setting, and participants

The Avon Longitudinal Study of Parents and Children (ALSPAC) is a prospective cohort study comprising all live births between April 1, 1991, and December 31, 1992, in Avon, England. The dates of analysis were September 2015 to July 2016. Participants who underwent cognitive testing at ages 18 months and 4, 8, 15, and 20 years and psychiatric assessment at age 18 years were included.

Main outcomes and measures

Individuals with psychotic disorder, psychosis with depression, psychotic experiences, and depression were compared with controls. Outcomes were full-scale, verbal, and nonverbal IQ at ages 18 months and 4, 8, 15, and 20 years, as well as measures of processing speed, working memory, language, visuospatial ability, and attention at ages 8 and 20 years.

Results

The following numbers of individuals were available for analyses in this longitudinal birth cohort study: 511 (238 male [46.6%]) at age 18 months (mean [SD] age, 1.53 [0.03] years), 483 (229 male [47.4%]) at age 4 years (mean [SD] age, 4.07 [0.03] years), 3930 (1679 male [42.7%]) at age 8 years (mean [SD] age, 8.65 [0.29] years), 3783 (1686 male [44.6%]) at age 15 years (mean [SD] age, 15.45 [0.27] years), and 257 (90 male [35.0%]) at age 20 years (mean [SD] age, 20.06 [0.55] years). Individuals with psychotic disorder showed continually increasing deficits between infancy (18 months) and adulthood (20 years) in full-scale IQ (effect size of change [ESΔ] = -1.09, P = .02) and nonverbal IQ (ESΔ = -0.94, P = .008). The depression group showed a small, increasing deficit in nonverbal IQ (ESΔ = -0.29, P = .04) between infancy and adulthood. Between ages 8 and 20 years, the psychotic disorder group exhibited developmental lags (ie, slower growth) in measures of processing speed (ESΔ = -0.68, P = .001), working memory (ESΔ = -0.59, P = .004), and attention (ESΔ = -0.44, P = .001) and large, static deficits in measures of language (ES = -0.87, P = .005) and visuospatial ability (ES = -0.90, P = .001). There was only weak evidence for cognitive deficits in the psychosis with depression group and the psychotic experiences group.

Conclusions and relevance

The findings herein suggest that the origins of psychotic disorder involve dynamic developmental processes, affecting both verbal and nonverbal abilities throughout the first 2 decades of life and leading to increasing dysfunction. These developmental processes do not manifest in other psychiatric disorders, such as psychosis with depression and depression.

SUBMITTER: Mollon J

PROVIDER: S-EPMC5885954 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:Dopamine transporter deficiency syndrome due to SLC6A3 mutations is the first inherited dopamine 'transportopathy' to be described, with a classical presentation of early infantile-onset progressive parkinsonism dystonia. In this study we have identified a new cohort of patients with dopamine transporter deficiency syndrome, including, most significantly, atypical presentation later in childhood with a milder disease course. We report the detailed clinical features, molecular genetic findings and in vitro functional investigations undertaken for adult and paediatric cases. Patients presenting with parkinsonism dystonia or a neurotransmitter profile characteristic of dopamine transporter deficiency syndrome were recruited for study. SLC6A3 mutational analysis was undertaken in all patients. The functional consequences of missense variants on the dopamine transporter were evaluated by determining the effect of mutant dopamine transporter on dopamine uptake, protein expression and amphetamine-mediated dopamine efflux using an in vitro cellular heterologous expression system. We identified eight new patients from five unrelated families with dopamine transporter deficiency syndrome. The median age at diagnosis was 13 years (range 1.5-34 years). Most significantly, the case series included three adolescent males with atypical dopamine transporter deficiency syndrome of juvenile onset (outside infancy) and progressive parkinsonism dystonia. The other five patients in the cohort presented with classical infantile-onset parkinsonism dystonia, with one surviving into adulthood (currently aged 34 years) and labelled as having 'juvenile parkinsonism'. All eight patients harboured homozygous or compound heterozygous mutations in SLC6A3, of which the majority are previously unreported variants. In vitro studies of mutant dopamine transporter demonstrated multifaceted loss of dopamine transporter function. Impaired dopamine uptake was universally present, and more severely impacted in dopamine transporter mutants causing infantile-onset rather than juvenile-onset disease. Dopamine transporter mutants also showed diminished dopamine binding affinity, reduced cell surface transporter, loss of post-translational dopamine transporter glycosylation and failure of amphetamine-mediated dopamine efflux. Our data series expands the clinical phenotypic continuum of dopamine transporter deficiency syndrome and indicates that there is a phenotypic spectrum from infancy (early onset, rapidly progressive disease) to childhood/adolescence and adulthood (later onset, slower disease progression). Genotype-phenotype analysis in this cohort suggests that higher residual dopamine transporter activity is likely to contribute to postponing disease presentation in these later-onset adult cases. Dopamine transporter deficiency syndrome remains under-recognized and our data highlights that dopamine transporter deficiency syndrome should be considered as a differential diagnosis for both infantile- and juvenile-onset movement disorders, including cerebral palsy and juvenile parkinsonism.