Executive functioning in schizophrenia: a thorough examination of performance on the Hayling Sentence Completion Test compared to psychiatric and non-psychiatric controls.
BACKGROUND
The current study examined executive functioning in schizophrenia by assessing response initiation and suppression in a group of schizophrenia patients, and drawing comparisons with psychiatric and non-psychiatric control groups.


METHODS
The Hayling Sentence Completion Test was used as a measure of executive functioning and was completed by 39 schizophrenia patients, 40 bipolar disorder patients and 44 healthy control participants. Outcome measures included response initiation and response suppression latency and error rate.


RESULTS
The schizophrenia group was significantly impaired on all measures of the Hayling Sentence Completion Test when compared to healthy control participants, and only on some of the measures when compared to the bipolar disorder group. The bipolar disorder group did not differ in performance compared to the healthy control group. Overall schizophrenia patients showed longer response initiation and response suppression latencies, and an increased error rate. Performance of the schizophrenia patients was associated with higher ratings of cognitive disorganisation. Performance was not related to age, gender, predicted IQ or any other clinical characteristics.


CONCLUSIONS
Schizophrenia patients show a slowing in baseline response initiation and slowed suppression of an inappropriate response. Considering the bipolar disorder patients demonstrated intact performance, altered executive functioning in schizophrenia appears relatively specific to the disorder rather than reflecting other characteristics common to mental illness. Investigations examining which neurocognitive domains are impaired in schizophrenia provide direct implications for treatment options tailored to an individual's cognitive strengths and weaknesses.
Joshua
Nicole
N
Mental Health Research Institute of Victoria, Level 2, 161 Barry Street, Carlton South Victoria 3053, Australia. nickijoshua@gmail.com
Gogos
Andrea
A
Rossell
Susan
S
D000328:Adult; D000704:Analysis of Variance; D000928:Antidepressive Agents / Q000494:pharmacology / Q000627:therapeutic use; D014150:Antipsychotic Agents / Q000494:pharmacology / Q000627:therapeutic use; D001714:Bipolar Disorder / Q000188:drug therapy / Q000503:physiopathology*; D032882:Comprehension / Q000502:physiology; D056344:Executive Function / Q000187:drug effects / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011569:Psychiatric Status Rating Scales; D011930:Reaction Time / Q000187:drug effects / Q000502:physiology; D012559:Schizophrenia / Q000188:drug therapy / Q000503:physiopathology*; D012565:Schizophrenic Psychology; D013223:Statistics as Topic; D014705:Verbal Behavior / Q000187:drug effects / Q000502:physiology*
D000928:Antidepressive Agents; D014150:Antipsychotic Agents