0
Get Alert
Please Wait... Processing your request... Please Wait.
You must sign in to sign-up for alerts.

Please confirm that your email address is correct, so you can successfully receive this alert.

1
Brief Report   |    
Sex Differences in Neuropsychological Functioning of First-Episode and Chronically Ill Schizophrenic Patients
Anne L. Hoff, Ph.D.; Mary Wieneke, Ph.D.; William O. Faustman, Ph.D.; Robert Horon, Ph.D.; Michael Sakuma, Ph.D.; Howard Blankfeld, M.D.; Scott Espinoza, A.A.; Lynn E. DeLisi, M.D.
Am J Psychiatry 1998;155:1437-1439.
Abstract

Objective:The purpose of this study was to determine whether men and women with schizophrenia demonstrate differences in cognitive abilities.Method:Two cohorts of patients with schizophrenia, an acute first-episode and a chronically hospitalized group, were evaluated with a neuropsychological battery and compared with a normal group of subjects.Results:After adjustment for age, age at onset, and premorbid IQ, male chronic patients performed worse than female chronic patients on measures of visual memory. These differences were eliminated after control for symptom severity. No other differences were found in cognitive function between men and women in either cohort.Conclusions:Sex differences in cognitive function in schizophrenic patients are not robust findings. Am J Psychiatry 1998; 155: 1437-1439

Abstract Teaser
Figures in this Article

Although female subjects with schizophrenia have a later age at onset and better clinical outcome than male subjects do, the literature examining sex differences in neuropsychological function of schizophrenic patients is less clear. Previous studies failed to account for age at onset or illness severity, have not included normal comparison groups, and have used relatively small and heterogeneous samples R2115510BDBBGHDI-R2115510BDBCEFDA.

We evaluated cognitive functioning in two homogeneous groups of schizophrenic patients with different durations and severities of illness. Early age at onset has been associated with worse performance on some cognitive measures R2115510BDBCIGDB. Accordingly, we predicted that 1) male patients would demonstrate greater impairment than female patients, and 2) no sex differences in cognitive functioning would emerge after control for age at onset.

Cohort 1. Inpatients consecutively admitted to an acute research unit for first-episode schizophrenia in Stony Brook, N.Y. (N=58; 41 men, 17 women), gave written informed consent for participation, as previously detailed R2115510BDBDJJJA. All patients met DSM-III-R criteria for chronic schizophrenia at 2-year follow-up. The mean age for men was 25.8 years (SD=6.2), and for women, 30.4 (SD=8.0); the mean ages at onset of psychotic symptoms were 24.2 (SD=5.6) and 29.8 years (SD=7.8), respectively.

Cohort 2. Chronic inpatients from Napa State Hospital (N=74; 51 men, 23 women) with a DSM-III-R diagnosis of schizophrenia gave written informed consent for participation (previously detailed R2115510BDBCIGDB). The mean age for men was 35.1 years (SD=8.3), and for women, 40.3 (SD=9.5); the mean ages at onset were 16.6 (SD=4.2) and 20.3 years (SD=4.9), respectively. Thus, this cohort had been ill for an average of 18.9 years (SD=7.9).

Patient groups were rated with the Brief Psychiatric Rating Scale (BPRS) R2115510BDBBHJJB within 2 weeks of testing. Negative symptom and positive symptom scales were constructed as described previously R2115510BDBCIGDB. There was a statistically significant group-by-sex interaction for positive symptoms (F=5.6, df=1, 118, p<0.02); post hoc Tukey tests indicated that chronically ill men had higher scores than women (p<0.03). There were no significant differences in chlorpromazine or benztropine equivalents between sexes in either cohort.

A normal comparison group (N=74; 56 men, 18 women; mean ages=32.1 [SD=9.6] and 24.2 years [SD=4.9], respectively) was recruited from the community near cohort 1, gave written informed consent, and was screened with structured psychiatric interviews R2115510BDBBDHFD.

A battery of tests measuring different cognitive domains was administered to all three groups R2115510BDBBDHFD. In order to control for differences between patient and comparison groups on demographic variables known to influence test performance, we performed group-by-sex multivariate analyses of covariance (MANCOVAs) on dependent measures from six cognitive domains, using age and the Reading score from Wide-Range Achievement Test—Revised (WRAT-R) as covariates. WRAT-R Reading score has been shown to be the best measure of premorbid intellectual functioning in psychotic disorders R2115510BDBDEHEB. All tests contributing to each domain are listed in T1. Analyses were repeated with age at onset as a third covariate. When the overall MANCOVA was statistically significant, univariate tests (analyses of variance) were performed.

There were statistically significant group effects for all cognitive domains (p<0.0001), indicating that schizophrenic patients performed worse than the comparison group. There were also overall main effects for sex in executive (F=2.8, df=5, 194, p<0.02), verbal memory (F=3.4, df=7, 192, p<0.002), spatial memory (F=3.6, df=4, 195, p<0.008), and concentration/speed (F=2.0, df=7, 192, p<0.05) domains. Men performed better than women in all domains except verbal memory, where women performed significantly better.

There were statistically significant group-by-sex interactions for spatial memory (F=2.1, df=8, 390, p<0.03) and sensory-perceptual (F=2.0, df=8, 390, p<0.05) domains. Univariate tests revealed statistically significant interactions for number of errors on the Benton Visual Retention Test (F=3.1, df=2, 198, p<0.05) and immediate score on Visual Reproduction (F=3.1, df=2, 198, p<0.05). Post hoc analyses indicated that chronically ill men were more impaired than women on the Benton Visual Retention Test (Tukey’s honestly significant difference, p<0.02). For the sensory-perceptual interaction, none of the univariate analyses of covariance (ANCOVAs) was statistically significant.

When MANCOVAs were repeated with age at onset added as a covariate, both spatial memory (F=2.6, df=4, 122, p<0.04) and sensory-perceptual (F=2.4, df=4, 122, p<0.05) MANCOVAs remained statistically significant. However, only the univariate test for the Benton Visual Retention Test reached statistical significance (F=5.5, df=1, 125, p<0.02), with chronically ill schizophrenic men having significantly more errors on the test than chronically ill women (Tukey’s honestly significant difference, p<0.03).

Because male chronic schizophrenic patients demonstrated significantly greater positive symptoms than women and because some BPRS positive and negative symptom scales correlated with spatial memory tests, ANCOVA analyses were repeated with positive and negative symptoms added as covariates for each spatial memory variable. There were no significant differences between the sexes on these ANCOVAs.

Contrary to our prediction, chronically ill schizophrenic men were more impaired than women on measures of spatial memory after control for differences in age at onset. However, those differences were eliminated after symptom differences between men and women were taken into account. Thus, we found no sex differences in cognitive functioning in two groups of schizophrenic patients, a first-episode cohort and a severely ill group, after taking into consideration normally occurring sex-related differences in cognitive abilities, age at onset, and symptom expression. Consistent with the literature on general sex differences in cognitive abilities R2115510BDBDEBAG, men performed better than women on measures of spatial memory, spatial problem-solving ability, and pure motor speed, while women were superior to men on verbal memory.

Controlling for differences due to sex-related symptomatic expressions of the illness biases the results against finding a sex difference in cognition. However, if differences in cognition between male and female schizophrenic patients are due to differences in symptoms themselves or time at onset, then cognitive sex differences in schizophrenia may reflect symptom variation and onset differences between the sexes. Identifying causes for differences on these measures may elucidate the neurodevelopmental and pathophysiological underpinnings of schizophrenia.

Presented in part at a meeting of the American College of Neuropsychopharmacology, San Juan, Puerto Rico, December 1996.Received June 9, 1997; revision received April 20, 1998; accepted May 5, 1998. From the University of California, Davis–Napa Psychiatric Research Center, Napa State Hospital; Department of Psychiatry, University of California, Davis, School of Medicine, Sacramento; and the Department of Psychiatry and Behavioral Sciences, State University of New York at Stony Brook, N.Y.. Address reprint requests to Dr. Hoff, University of California, Davis–Napa Psychiatric Research Center, Napa State Hospital, 2100 Napa-Vallejo Highway, Napa, CA 94558. Supported by a Young Investigator Award from the National Alliance for Schizophrenia and Depression (Dr. Hoff), NIMH grant RO1-44233 (Drs. DeLisi and Hoff), the Department of Veterans Affairs, and the Department of Mental Health, State of California.

 
Goldstein JM, Seidman LJ, Santangelo S, Knapp P, Tsuang MT: Are schizophrenic men at higher risk for developmental deficits than schizophrenic women? Implications for adult neuropsychological functions. J Psychiatr Res  1994; 28:483–498
[PubMed]
[CrossRef]
 
Goldberg TE, Gold JM, Torrey EF, Weinberger DR: Lack of sex differences in the neuropsychological performance of patients with schizophrenia. Am J Psychiatry  1995; 152:883–888
[PubMed]
 
Andia A, Zisook S, Heaton R, Hesselink J, Jernigan T, Kuck J, Moranville J, Braff D: Gender differences in schizophrenia. J Nerv Ment Dis  1995; 183:522–528
[PubMed]
[CrossRef]
 
Perlick D, Mattis S, Stastny P, Teresi J: Gender differences in cognition in schizophrenia. Schizophr Res  1992; 8:69–73
[PubMed]
[CrossRef]
 
Lewine RRJ, Walker EF, Shurett R, Caudle J, Haden C: Sex differences in neuropsychological functioning among schizophrenic patients. Am J Psychiatry  1996; 153:1178–1184
[PubMed]
 
Hoff AL, Harris D, Faustman WO, Beal M, DeVilliers D, Mone RD, Moses JA Jr, Csernansky JG: A neuropsychological study of early onset schizophrenia. Schizophr Res  1996; 20:21–28
[PubMed]
[CrossRef]
 
DeLisi LE, Hoff AL, Schwartz JE, Shields GW, Halthore SN, Gupta SM, Henn FA, Anand AK: Brain morphology in first-episode schizophrenic-like psychotic patients: a quantitative magnetic resonance imaging study. Biol Psychiatry  1991; 29:159–175
[PubMed]
 
Overall JE, Gorham DR: The Brief Psychiatric Rating Scale. Psychol Rep  1962; 10:799–812
 
Hoff AL, Riordan H, O’Donnell D, Stritzke P, Neale C, Boccio A, Anand AK, DeLisi LE: Anomalous lateral sulcus asymmetry and cognitive function in first-episode schizophrenia. Schizophr Bull  1992; 18:257–270
[PubMed]
 
Kremen WS, Seidman LJ, Faraone SV, Pepple JR, Lyons MJ, Tsuang MT: The "3 Rs" and neuropsychological function in schizophrenia: an empirical test of the matching fallacy. Neuropsychology  1996; 10:22–31
[CrossRef]
 
Halpern DF: Sex Differences in Cognitive Abilities, 2nd ed. Hillsdale, NJ, Lawrence Erlbaum Associates, 1992
 
+

References

Goldstein JM, Seidman LJ, Santangelo S, Knapp P, Tsuang MT: Are schizophrenic men at higher risk for developmental deficits than schizophrenic women? Implications for adult neuropsychological functions. J Psychiatr Res  1994; 28:483–498
[PubMed]
[CrossRef]
 
Goldberg TE, Gold JM, Torrey EF, Weinberger DR: Lack of sex differences in the neuropsychological performance of patients with schizophrenia. Am J Psychiatry  1995; 152:883–888
[PubMed]
 
Andia A, Zisook S, Heaton R, Hesselink J, Jernigan T, Kuck J, Moranville J, Braff D: Gender differences in schizophrenia. J Nerv Ment Dis  1995; 183:522–528
[PubMed]
[CrossRef]
 
Perlick D, Mattis S, Stastny P, Teresi J: Gender differences in cognition in schizophrenia. Schizophr Res  1992; 8:69–73
[PubMed]
[CrossRef]
 
Lewine RRJ, Walker EF, Shurett R, Caudle J, Haden C: Sex differences in neuropsychological functioning among schizophrenic patients. Am J Psychiatry  1996; 153:1178–1184
[PubMed]
 
Hoff AL, Harris D, Faustman WO, Beal M, DeVilliers D, Mone RD, Moses JA Jr, Csernansky JG: A neuropsychological study of early onset schizophrenia. Schizophr Res  1996; 20:21–28
[PubMed]
[CrossRef]
 
DeLisi LE, Hoff AL, Schwartz JE, Shields GW, Halthore SN, Gupta SM, Henn FA, Anand AK: Brain morphology in first-episode schizophrenic-like psychotic patients: a quantitative magnetic resonance imaging study. Biol Psychiatry  1991; 29:159–175
[PubMed]
 
Overall JE, Gorham DR: The Brief Psychiatric Rating Scale. Psychol Rep  1962; 10:799–812
 
Hoff AL, Riordan H, O’Donnell D, Stritzke P, Neale C, Boccio A, Anand AK, DeLisi LE: Anomalous lateral sulcus asymmetry and cognitive function in first-episode schizophrenia. Schizophr Bull  1992; 18:257–270
[PubMed]
 
Kremen WS, Seidman LJ, Faraone SV, Pepple JR, Lyons MJ, Tsuang MT: The "3 Rs" and neuropsychological function in schizophrenia: an empirical test of the matching fallacy. Neuropsychology  1996; 10:22–31
[CrossRef]
 
Halpern DF: Sex Differences in Cognitive Abilities, 2nd ed. Hillsdale, NJ, Lawrence Erlbaum Associates, 1992
 
+
+

CME Activity

There is currently no quiz available for this resource. Please click here to go to the CME page to find another.
Submit a Comments
Please read the other comments before you post yours. Contributors must reveal any conflict of interest.
Comments are moderated and will appear on the site at the discertion of APA editorial staff.

* = Required Field
(if multiple authors, separate names by comma)
Example: John Doe



Web of Science® Times Cited: 56

Related Content
Articles
Books
Gabbard's Treatments of Psychiatric Disorders, 4th Edition > Chapter 27.  >
Textbook of Psychotherapeutic Treatments > Chapter 6.  >
The American Psychiatric Publishing Textbook of Geriatric Psychiatry, 4th Edition > Chapter 2.  >
Dulcan's Textbook of Child and Adolescent Psychiatry > Chapter 14.  >
Gabbard's Treatments of Psychiatric Disorders, 4th Edition > Chapter 42.  >
Topic Collections
Psychiatric News
APA Guidelines
PubMed Articles