Neurocognitive deficits evident in adolescents with psychotic-like symptoms
MedWire News: Adolescents with psychotic-like symptoms have impairments in receptive language, motor function, and executive function/speed of processing, study results show.
"It is well-established that individuals with schizophrenia, as a group, demonstrate significant impairments across a broad range of cognitive domains," explain Mary Cannon (Beaumont Hospital, Dublin, Ireland) and team.
"These deficits are evident even at the time of the first episode of schizophrenia and are likely to have begun even earlier in the course of the disease."
To investigate whether adolescents at risk for psychosis show cognitive deficits, the researchers studied 277 children, aged 11-13 years, from five schools in Dublin.
Of these, 17 who tested positive for possible psychotic symptoms using the seven-item Adolescent Psychotic-Like Symptom Screener (APSS) and 20 without any such symptoms underwent a battery of tests to assess motor skills, memory, expressive language, receptive language, abstract reasoning, attention, executive function, and scholastic ability.
The researchers found that adolescents with psychotic-like symptoms scored worse on receptive language skills than controls, at 114.5 versus 124.8 on the British Picture Vocabulary Scale.
Adolescents with psychotic-like symptoms also performed worse on tests of motor function and executive function/speed of processing than controls, with scores of 12.9 versus 13.7 on the Pegboard test, and 41.7 versus 36.4 and 60.6 versus 48.9 on the Trail-Making A and B tests, respectively. Higher scores on the Trail-Making test indicate poorer performance.
There were no significant differences between the groups on other neurocognitive measures.
Cannon and team conclude in the journal Schizophrenia Research: "Taken together with the results from birth cohort, genetic high risk and prodromal studies, these findings are consistent with a neural inefficiency/disconnectivity hypothesis in those at risk for psychosis."
They add: "These results highlight the need to investigate developmental brain circuits subserving language and motor function and processing speed and how these change over time in at-risk adolescents."
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By Mark Cowen