It is unclear if the commonly observed “subcortical”
verbal memory profile in schizophrenic patients is present at the onset of
the disease. Therefore, the performance of 43 first-episode patients with
schizophrenia or schizophreniform disorder on the Dutch version of the
California Verbal Learning Test (VLGT) was compared to that of 43 normal
comparison participants. We hypothesized that the first-episode patients
would exhibit a “subcortical” memory profile, that is, they
would show a primary retrieval deficit. This hypothesis was not confirmed:
the patients displayed a profile suggestive of a prominent storage
deficit, that is, a “cortical” memory profile. Subsequently,
patients' VLGT performance was cluster analyzed to determine whether
subgroups could be identified exhibiting a cortical, subcortical, and
normal profile, respectively. Two subgroups (N = 22; N =
13) exhibited memory impairments, while one subgroup (N = 8) was
unimpaired. The memory profiles of the two impaired subgroups differed
both qualitatively and quantitatively, but did not conform neatly to a
cortical and a subcortical profile. Demographic and verbal fluency data
provided limited validation of the subgroup classification. Our results
may suggest that combining the verbal memory performance of first-episode
patients obscures meaningful heterogeneity. Alternatively, the cluster
solution could merely reflect a continuum of severity. (JINS,
2005, 11, 152–162.)