The course of neuropsychological functioning in young people with attenuated vs discrete mental disorders

Clinical staging of mental disorders is designed to facilitate the selection of stage-appropriate interventions, early in the course of illness. Neuropsychological performance, particularly at early stages of mental disorder, is a strong predictor of medium-term functional outcomes. Despite this, the longitudinal examination of neuropsychological profiles in early stages of illness is poorly researched. Thus, we examined baseline and longitudinal neuropsychological profiles of young patients with attenuated syndromes vs those with discrete disorders.

Neuropsychological testing of 497 help-seeking young people (21.2 ± 3 years; 56% female). Clinical staging, assigned separately from testing, rated 262 individuals as "attenuated syndrome" (stage 1b) and 235 as "discrete" or "persistent" disorder (stage 2+). Follow-up testing was undertaken in 170 individuals (54% at stage 1b) after 19.8 ± 9 months (range: 3 to 51 months).

At baseline, attenuated and discrete/persistent disorders significantly differed in 4 of the 9 neuropsychological measures (verbal learning, verbal memory, visual memory and set shifting). Despite this, both groups showed similar improvement in neuropsychological functioning at follow-up, particularly in processing speed, sustained attention and visual memory. Longitudinal improvement in cognition corresponded with increases in socio-occupational functioning.

The degree of baseline neuropsychological dysfunction discriminates those with attenuated syndromes from those with a discrete/persistent disorder. Furthermore, improvement in neuropsychological functioning corresponded with improvement in clinical and functional status, despite stage of illness. This suggests that neuropsychological functioning remains relatively stable in young people with a mental illness and may be a critical window for intervention.