Background: Impairment in attention is prominent in schizophrenia and may be a valuable genetic indicator for vulnerability to this disease.
Aims: We set out to characterize the attention deficits that may be associated with genetic liability to schizophrenia.
Methods: We compared attention performance in 55 people with schizophrenia, 95 of their first-degree relatives, and 61 unrelated controls. We also segregated presumed obligate carriers of genetic risk (POCs, N=12) and compared their performance with that of controls.
Results: Although the relatives of people with schizophrenia did not significantly differ from the normal controls on the tasks of attention, their scores were significantly ordered such that patients>relatives>normal controls during tasks of sustained and selective attention as measured by the Jonckheere-Terpstra Test (p<.05). Additionally, POCs were significantly worse than normal controls during selective attention tasks such as the Stroop (p=.03) and Letter Cancellation Task (p=.04).
Conclusions: Heterogeneity in the first-degree relatives may have diluted the attention deficits present in those who are at genetic risk for schizophrenia. On the other hand, our findings in the more homogeneous group of POCs suggest that selective attention may be an indicator of genetic liability for schizophrenia.