Childhood Intelligence of Future Schizophrenics and Neighborhood Peers

Premorbid IQ in Schizophrenia: A Meta-Analytic Review

“…For the cross-sectional analysis, three studies contributed effect sizes from testing conducted exclusively during childhood (17,19,22). Six studies contributed effect sizes from testing conducted during childhood and adolescence or at unspecified ages (18,20,23,27,30,31), and nine studies contributed effect sizes from testing conducted exclusively during adolescence and early adulthood (15, 16, 21, 24-26, 28, 29, 32). As shown in Figure 3, we found no crosssectional evidence of a decline in IQ with age during the premorbid period.…”

“…Eight of the remaining 26 studies provided data on samples for which another published study reported more complete or up-to-date data. Table 1 details the basic study descriptors and mean effect sizes for the 18 studies included in our analyses (15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32). (For the list of excluded studies and the study descriptors [location and design], see the data supplement accompanying the online version of this article.…”

“…b More than one effect size per study is included when data were provided separately by test or age of testing. Effect sizes were estimated using Cohen's d: (M 1 +M 2 )/square root ([(n 1 -1)(SD 1 ) 2 +(n 2 -1)(SD 2 ) 2 ]/[n 1 +n 2 -2]), with the following qualifications: the Brewer et al (16) (28), the effect size was estimated from the critical ratio using the same equation provided for Cannon et al [17] and Albee et al [27]). Although Offord (30) reported data from matched pairs, the effect size was calculated using sample means and standard deviations per Dunlap et al (33).…”

Meta-analyses of cognitive and motor function in youth aged 16 years and younger who subsequently develop schizophrenia

“…Among the 34 studies, 10 contained samples that overlapped (Lane & Albee, 1963, 1968Albee et al 1964 ;Cannon et al 2000Cannon et al , 2002Cannon et al , 2006Niendam et al 2003 ;Seidman et al 2006). A co-author independently reviewed these studies to verify that inclusion criteria were met.…”

Data‐processing levels and thought disorder in schizophrenia

“…In this connection, it is relevant to note the recent studies by Albee and his colleagues. They have obtained childhood intelligence records of adult schizophrenics and claim to have shown that the childhood and adult IQs are not different (Albee, Lane, Corcoran & Werneke, 1963); that, even as children, the schizophrenics-to-Ilc had lower IQs than the normative averages of children in their own class (Albee, Lane & Reuter, 1964); that they had lower IQs than their siblings as children (Lane & Albee, 1964); and that deterioration is evident during childhood (Lane & Albee, 1963). They conclude that the adult schizophrenic has been subjected to progressive intellectual deterioration during childhood and that the deficit is completed before adult breakdown.…”