Course of intelligence deficits in early onset, first episode schizophrenia: a controlled, 5-year longitudinal study

Abstract

Only few prospective longitudinal studies have assessed the course of intelligence deficits in early onset schizophrenia (EOS), and these have used different age appropriate versions of Wechsler Intelligence Scales and age appropriate norms. The post-psychotic development of intelligence in EOS has predominantly been characterized as relatively stable in these studies. However, comparisons of IQs from different test versions based on the different norms may not permit unequivocal interpretations. The objective of the current study was to compare the development of intelligence in EOS patients (N = 10) from their first psychotic episode to 5 years of post onset with that of healthy controls (N = 35) and patients who at baseline had been diagnosed with other non-affective psychoses (N = 8). The same version of a Wechsler Intelligence Scale was administered at both baseline and follow-up assessments, and the same norms were used to derive IQs at baseline and followup. Significantly smaller change in mean full scale intelligence quotient (FSIQ) was found in diagnostically stable EOS patients compared with healthy controls during the follow-up period. However, no statistically significant difference in mean FSIQ change was observed between patients with EOS and patients with other non-affective psychoses, although this result must be interpreted with caution due to the small sample sizes. The results suggest abnormally slow acquisition of new intellectual information and skills in EOS patients during the first 5 years after full clinical presentation.

Profile of cognitive deficits and associations with depressive symptoms and intelligence in chronic early‐onset schizophrenia patients

“…One patient and one healthy control subject were too young for the WAIS, and their full scale intelligence quotient (FSIQ) was assessed using the Wechsler Intelligence Scale for Children – third version (WISC‐III) (Wechsler, ). This test battery was administered at the 5‐year follow‐up assessment only, and did not overlap with the previously reported test battery administered at both baseline and follow‐up in our longitudinal studies (Jepsen et al., , ). Thus, the current cognitive data are cross‐sectional and have not been reported previously.…”

“…Stable intelligence deficits have been found in patients with EOS and in patients with childhood onset schizophrenia (COS, onset by age 12) over several years (Frangou, Hadjulis & Vourdas, ; Gochman, Greenstein, Sporn et al ., ). However, an IQ decline has also been found in COS patients (Bedwell, Keller, Smith, Hamburger, Kumra & Rapoport, ), and subnormal acquisition of new intellectual information and skills has been observed in EOS patients between adolescence and young adulthood in the current sample (Jepsen, Fagerlund, Pagsberg et al ., ). A significant deterioration in verbal memory and attention as well as a maturational arrest in speed of information processing have been observed between late adolescent and adulthood (Frangou et al ., ; Oie & Hugdahl, ; Oie, Sundet & Rund, ).…”

Early detection and intervention of psychosis in children and adolescents: urgent need for studies

“…They can lead to delays in the maturation of neuropsychological functions in affected children and adolescents and longterm neuropsychological deficits [1,2] as well as significant impairments in psychosocial functioning [3]. This makes schizophrenia one of the six leading causes of years lived with disability [4].…”

Do clinical characteristics predict the cognitive course in early‐onset schizophrenia‐spectrum disorders?

“…A limitation of our study is the modest sample size, hence opening for the possibility that a larger sample might reveal more significant associations between clinical variables and long‐term cognition. The incidence of EOS is very low, and we included all potential participants in Norway over a period of 4 years and arrived at a group size that complies with other EOS studies (Frangou et al., ; Jepsen, Fagerlund, Pagsberg, Christensen, Hilker, et al., ; Oie & Rund, ), with a similar attrition rate (Fraguas et al., ; Kravariti et al., ,b; Wozniak et al., ). Also, the sample size matches comparable EOS and first episode schizophrenia studies using the same neuropsychological test battery (Fu, Czajkowski, Rund, & Torgalsboen, ; Holmen et al., ).…”