A prospective 3-year longitudinal study of cognitive predictors of relapse in first-episode schizophrenic patients.
BACKGROUND
Cognitive predictors of relapse have been extensively explored only in few long term longitudinal studies of first-episode schizophrenia.


METHODS
This study prospectively followed 93 patients with first-episode schizophrenia, schizophreniform disorder, and schizoaffective disorder for 3 years after their first-episode illness. Cognitive domains including verbal intelligence, verbal and visual memory, verbal fluency, and Wisconsin Card Sorting Test performance were investigated as potential predictors of relapse.


RESULTS
We found that by the first year 21% patients had relapsed, by the second year 33% had relapsed, and by the third year 40% had relapsed. There was a significant difference in the relapse rate between patients with good adherence and patients with poor adherence to medication regimes. A multiple logistic regression analysis revealed that after controlling for medication adherence, perseverative error in the Wisconsin Card Sorting Test was the only cognitive function that significantly predict relapse with an odds ratio of 2.4.


CONCLUSIONS
Cognitive flexibility in set shifting is related to tendency towards relapse in first-episode schizophrenic patients. Other cognitive factors appear not to be related to relapse. Possible mechanisms included the link between prefrontal dysfunction and sub-cortical dopamine system stability, as well as the effects of executive dysfunction on insight impairment and adherence behavior.
Chen
Eric Yu-Hai
EY
Department of Psychiatry, University of Hong Kong, Queen Mary Hospital, Pokfulam Road, Hong Kong. eyhchen@hku.hk
Hui
Christy Lai-Ming
CL
Dunn
Eva Lai-Wah
EL
Miao
May Yin-King
MY
Yeung
Wai-Song
WS
Wong
Chi-Keung
CK
Chan
Wah-Fat
WF
Tang
Wai-Nang
WN
D000293:Adolescent; D000328:Adult; D003071:Cognition / Q000502:physiology*; D003072:Cognition Disorders / Q000209:etiology*; D016001:Confidence Intervals; D005260:Female; D006801:Humans; D007360:Intelligence / Q000502:physiology; D007361:Intelligence Tests / Q000706:statistics & numerical data; D016015:Logistic Models; D008137:Longitudinal Studies; D008297:Male; D008568:Memory / Q000502:physiology; D008875:Middle Aged; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D016017:Odds Ratio; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012008:Recurrence; D012559:Schizophrenia / Q000150:complications*; D012565:Schizophrenic Psychology; D012720:Severity of Illness Index; D014705:Verbal Behavior / Q000502:physiology