Discrepancy of Wechsler Adult Intelligence Scale-III Scores in

Preparing to load PDF file. please wait...

0 of 0
100%
Discrepancy of Wechsler Adult Intelligence Scale-III Scores in

Transcript Of Discrepancy of Wechsler Adult Intelligence Scale-III Scores in

Original Article

Taiwanese Journal of Psychiatry (Taipei) Vol. 24 No. 3 2010 • 191 •

Discrepancy of Wechsler Adult Intelligence Scale-III Scores in Recently Detoxified Han
Taiwanese Male Alcoholic Patients
Ming-Chi Huang, M.D.1,2, Chun-Hsin Chen, M.D., M.S.2,3, Yen-Long Chiou, B.D.1, Shih-Ku Lin, M.D.1,2

Objectives: Chronic alcohol consumption can lead to neuropsychological impairment. The Wechsler Adult Intelligence Scale-III (WAIS-III) provides sub-domain information of intellectual functioning. In this study we aimed to investigate the abnormal discrepancies in WAIS-III among Han Taiwanese male patients with alcohol dependence. Methods: Following one-week of alcohol detoxification treatment, male inpatients fulfilling the DSM-IV criteria of alcohol dependence were assessed using WAIS-III. We defined abnormal discrepancy as the score difference between verbal intelligent quotient (VIQ) and performance intelligent quotient (PIQ), verbal comprehension index (VCI) and perceptual organization index (POI), and working memory index (WMI) and processing speed index (PSI) greater than 15, 17, and 21, respectively. We compared differences of demographic and clinical variables between patients with (discrepancy group) or without (nondiscrepancy group) abnormal VIQ/PIQ or VCI/POI discrepancies. Results: Thirty-three male patients (mean age: 40.8 ± 7.4 years) completed the WAIS-III evaluation. Compared to the norm, alcoholic subjects were found to have lower PIQ scores, due to significantly poorer POI (p < 0.05) and PSI (p < 0.05) performance. There were abnormal VIQ/PIQ, VCI/POI, or WMI/PSI discrepancies in 10 (30.3%), 8 (24.2%), and 9 (27.3%) patients, respectively. The POI subtest scores, including picture completion, block design, and picture arrangement, were significantly lower (p < 0.05) in the discrepancy group (N = 12) than non-discrepancy group (N = 21). Both groups did not differ significantly in demographic or drinking-related variables. Conclusion: Compared to Taiwanese norm, our recently detoxified alcoholic males were likely to have lower PIQ. They also showed higher frequencies of abnormal VIQ/PIQ, VCI/POI, or WMI/PSI discrepancies as defined by the study.
Key words: Wechsler Adult Intelligence Scale III, neuropsychology, alcohol dependence,
discrepancy
(Taiwanese Journal of Psychiatry [Taipei] 2010; 24: 191-200)
1 Taipei City Psychiatric Center, Taipei City Hospital Song-De Branch, Taipei, Taiwan 2 Department of Psychiatry, Taipei Medical University, Taipei, Taiwan 3 Department of Psychiatry, Taipei Medical University-Wan-Fang Hospital, Taipei, Taiwan Received: October 8, 2009; revised: June 30, 2010; accepted: August 4, 2010 Address correspondence to: Dr. Shih-Ku Lin, Department of Psychiatry, Taipei City Hospital and Psychiatric Center, No. 309, Songde Road, Taipei 110, Taiwan

• 192 • Discrepancy of WAIS-III Scores in Alcoholics

Introduction
Chronic alcohol consumption is associated with neuropsychological impairment in learning, memory, abstract reasoning, problem solving, visuospatial functioning, and information processing [1]. Central nervous system pathologies among alcoholics are shown in neuropsychological or functional imaging studies [2, 3]. Regarding neuropsychological deficits associated with long-term drinking, some studies [4-7] using individual and independent measures cannot delineate discrepancies among various aspects of neuropsychological functions.
The Wechsler Adult Intelligence Scale-III (WAIS-III) is an instrument designed to measure multiple domains of intellectual functioning [8]. WAIS-III is used to disclose discrepancies between various domains. Normal intelligence among alcoholics has been reported using a previous edition of WAIS or WAIS-III as the assessment tool [8,9]. But for recently abstinent alcoholic patients, in the WAIS-III Technical Manual that the Verbal scores (including Verbal Comprehension and Working Memory) has been found to be slightly higher than the performance scores (including perceptual organization and the processing speed) [8, 9].
Even following long-term abstinence, deficits in the spatial processing domain still exist in alcoholic individuals although the performance on other neuro-cognitive assessments are similar to normal controls [10]. In a recent study, the performance on block design in alcoholics is shown to be decreased with their age, and its decrease can be predicted by the extent of brain shrinkage [11].
Ethnic differences exist in alcohol-metabolizing genes, especially in those to express alcohol

dehydrogenase and aldehyde dehydrogenase activity [12]. Different genotyping of these genes is correlated to some neuropsychiatric deficits [13]. Because these studies have been mainly conducted in patients with alcohol dependence in Western countries, investigating the differences of neuropsychological performance among those in Asians is worthwhile.
The aims of this study were: (A) to examine the performance profile of WAIS-III and pertinent abnormal discrepancies in Taiwanese patients with alcohol dependence as well as (B) to discover any association between demographic or various drinking variables with their abnormal discrepancies in WAIS-III.
Methods
Study subjects The study was conducted in the alcohol de-
toxification ward of Taipei City Psychiatric Center located in northern Taiwan, and was approved by its institutional review board. We recruited Han Taiwanese male patients who were aged of 20-60 years, were admitted for alcohol detoxification, and met the DSM-IV criteria of alcohol dependence diagnosed by at least two psychiatrists. Excluded were those who: (A) were comorbid with other current non-nicotine substance abuse or dependence; (B) had significant physical illnesses, like ischemic heart disease or poorly controlled diabetes mellitus; (C) had other psychiatric disorders such as schizophrenia, bipolar disorder, or major depressive disorder; (D) had been treated with antipsychotic drugs or antidepressants, or had used benzodiazepine regularly for more than one week before admission; (E) and had severe cognitive impairment with difficulty in understanding the study content.

Huang MC, Chen CH, Chiou YL, et al. • 193 •

Eligible subjects received physical examinations and urine toxicology tests to screen for illicit drugs and exclude other substance use disorders. After initial assessment, we recruited all eligible patients with a comprehensive description of the study, and obtained written informed consent.
Study procedures We obtained subjects’ socio-demographic
data (ages, educational levels, and occupational statuses), as well as alcohol consumption history, including age of first alcohol drinking, age of meeting the diagnosis of alcohol dependence, daily drinking amount in the past three months (g/ day), and presence of alcohol-related severe complications such as alcohol withdrawal delirium and alcohol withdrawal seizures. We recorded the duration (days) from the day of subjects’ last drink, and the duration from the day of their admisstion to that of their receiving WAIS-III test. The subjects stopped drinking alcohol immediately and completely on admission. The patients received a fixed-dose alcohol detoxication schedule with oral lorazepam 8 mg/day in 4 divided doses, and with gradual tapering off in one week. At the same time, they received vitamin B1 and multi-vitamin supplements, and as-needed use of oral trazodone 50 mg at night for sleeping problems.
The assessment tool: WAIS-III One trained psychologist performed the
WAIS-III test for the subjects who had been detoxified for at least seven days (range, 8-26 days). WAIS-III which is a revision of the WAIS-R, has some key revisions in updating the norms, extenting of the age range to 89 years, modifying some test items, relying less on timed performance for computing performance intelligence quotient (PIQ), and having extensive testing of reliability and validity.

WAIS-III has 14 subtests related to four hypothesized factors: verbal comprehension index (VCI), perceptual organization index (POI), working memory index (WMI), and processing speed index (PSI). The index subtests can generate the verbal intelligence quotient (VIQ), performance intelligence quotient (PIQ), and full-scale intelligence quotient (FSIQ).
After reestablishing norms in local subjects with accompanying revisions of some culturegrounded items, Chen and Chen in 2002 validated the Chinese version of WAIS-III [14].
Definitions of abnormal discrepancies The following analyses were done based on
the information from Taiwanese norms. Substantial individual differences in VIQ/PIQ discrepancies exit in the normal population, therefore, to define the “abnormal” magnitude of the discrepancy is important. In this study, the extreme 15% of norm in the population (about one standard deviation above the mean) was considered “abnormal” [15], meaning that the corresponding scores at the extreme 15% of normal discrepancies between VIQ and PIQ were used as scores to define abnormal discrepancy. Thus, abnormal VIQ/PIQ discrepancy was defined by a difference in VIQ/PIQ scores >15.
Likewise, abnormal discrepancies for factor indices, VCI/POI and WMI/PSI, were also defined by referring to corresponding scores with the extreme 16.4% (without exact 15% corresponding score in the reference) and 15% of discrepancy in norms, respectively. Hence, we defined abnormal VCI/POI and WMI/PSI discrepancies with differences in scores >17 and >21, respectively. We classified subjects with abnormal VIQ/PIQ or VCI/POI discrepancies as the discrepancy group and those without such discrepancies as the nondiscrepancy group.

• 194 • Discrepancy of WAIS-III Scores in Alcoholics

Statistical analyses Descriptive statistics were used to present
the distribution of demographic variables, IQ, four factor scores, and the frequency of abnormal VIQ/ PIQ, VCI/POI, and WMI/PSI discrepancies. We used Fisher’s exact test to test the association between categorical demographic variables and presence of abnormal discrepancies. We also used logistic regression to examine categorical drinking variables and abnormal discrepancies. The Kolmogorov-Smirnov test was used if the distribution of data of various subtests was not normally distributed. Non-parametric Wilcoxon rank

sum test was used to test differences between the two groups.
We used Statistical Package for Social Science version 15.0 software (SPSS Inc., Chicago, Illinois, USA) to analyze all data. The differences between groups were considered significant if pvalues were small than 0.05.
Results
Table 1 lists the mean, standard deviation, and range of WAIS-III performance in all 33 participants. Table 2 shows subjects’ demographic

Table 1. The mean, standard deviation, and range of WAIS-III performance in alcoholic patients (N = 33)

IQ scores FSIQ VIQ PIQ
Indices VCI POI WMI PSI
Subtests Vocabulary Similarities Arithmetic Digit span Information Comprehension Picture completion Digit symbol-coding Block design Matrix reasoning Picture arrangement Symbol search

Mean
90.1 95.0 85.2
95.2 86.1 96.0 83.5
8.3 8.8 10.1 10.0 9.1 7.1 6.0 7.0 8.7 9.1 8.6 7.7

SD

Range

11.5

70-121

10.8

73-122

12.6

66-116

11.0

71-125

13.5

68-111

12.2

67-121

14.1

60-116

2.6

2-14

1.8

3-13

3.0

3-18

2.7

5-18

2.3

5-15

2.8

3-13

3.2

2-15

2.6

2-13

2.9

4-14

2.9

3-17

2.5

4-12

2.6

3-14

Abbreviations: WAIS-III = The Wechler Adult Intelligence Scale-III, SD = standard deviation, FSIQ = full scale intelligence quotient, VIQ = verbal intelligence quotient, PIQ = performance intelligence quotient, VCI = verbal comprehension index, POI = perceptual organization index, WMI = working memory index, and PSI = processing speed index

Huang MC, Chen CH, Chiou YL, et al. • 195 •

Table 2. Demographic and drinking characteristics of the non-discrepancy and discrepancy groups

Age, y/o (SD) Years of education (SD) Job, N (%)
Employed Unemployed Age of first drink, y/o (SD) Age of alcohol dependence, y/o (SD) Daily drinking amount, g/d (SD) PHx of withdrawal seizure, n (%) PHx of withdrawal delirium, n (%) Duration of abstinence prior to WAIS-III performance, days (SD) Duration of admission prior to WAIS-III performance, days (SD)

Patients with alcohol dependence

Non-discrepancy (N = 21)

Discrepancy (N = 12)

41.0 (7.8)

40.5 (7.1)

11.4 (2.8)

10.8 (2.4)

6 (28.6) 15 (71.4) 17.9 (5.3) 30.1 (8.9) 216.0 (149.9) 5 (23.8) 5 (23.8) 14.5 (5.3)

6 (50.0) 6 (50.0) 18.3 (3.4) 28.8 (6.8) 174.2 (86.7) 4 (33.3) 5 (41.7) 14.6 (6.0)

12.5 (3.6)

12.6 (6.2)

Abbreviations: SD = standard deviation, PHx = previous history, y/o = years old, g/d = gram/day, and % = percent The non-discrepancy group refers to those without abnormal VIQ/PIQ or VCI/POI discrepancies. The discrepancy group refers to the group of patients with abnormal VIQ/PIQ or VCI/POI discrepancies.

and drinking characteristics of the non-discrepancy and discrepancy groups. Table 3 represents the intelligent quotient, factor indices and subtests of WAIS-III in those two groups. And the Figure 1 depicts the frequency of abnormal discrepancies between VIQ and PIQ, VCI and POI, and WMI and PSI as defined by the above mentioned criteria.
Discussion
Increasing evidence indicates that alcoholism is associated with impaired performance in various cognitive functions evaluated using clinical neuropsychological tests, and that the deficits are more pronounced in visual-spatial than in verbal functions [7, 16-20]. Compared to Taiwanese norms, this study sample of recently detoxified alcoholic men did not show any significant differ-

ences in FSIQ and VIQ of the WAIS-III (Table 3). But they signifcantly performed more poorly in PIQ (p < 0.05), attributable to low POI and PSI scores (Table 3). In this study, 30.3% of alcoholic subjects were also found to have abnormal VIQ/ PIQ discrepancy, higher than the norm of 7.5% (Figure 1). Meanwhile, the frequency of abnormal VCI/POI and WMI/PSI discrepancies are also higher than that of norm (24.2% vs. 8.2%, and 27.3% vs. 7.5%, respectively) (Figure 1). Compared to those without VIQ/PIQ or VCI/POI discrepancies (non-discrepancy group), alcoholic patients with such discrepancies (discrepancy group) has signifcantly more deficits in POI (p < 0.05), as well as the picture completion (p < 0.05), block design (p < 0.05), and picture arrangement (p < 0.05) subtests (Table 3).
In this study, we found that male alcoholics had a higher tendency not to manage information

• 196 • Discrepancy of WAIS-III Scores in Alcoholics

Table 3. The intelligent quotient, factor indices, and subtests of WAIS-III in the discrepancy and non-discrepancy groups

IQ FSIQ VIQ PIQ*
Factor Indices VCI POI* WMI PSI
Subtests Vocabulary Similarities Arithmetic Digit span Information Comprehension Picture completion* Digit symbol-coding Block design* Matrix reasoning Picture arrangement* Symbol search

Patients with alcohol dependence

Non-discrepancy (N = 21)

Discrepancy (N = 12)

92.1 (12.6) 94.7 (12.0) 89.7 (12.5)

86.7 (8.6) 95.6 (8.6) 77.4 (8.6)

94.4 (12.4) 90.3 (14.2) 95.1 (12.5) 85.2 (15.1)

96.5 (8.2) 78.8 (8.5) 97.5 (11.9) 80.7 (12.3)

8.1 (2.9) 8.7 (1.9) 8.8 (2.3) 9.7 (3.1) 9.9 (3.0) 9.3 (2.5) 8.1 (2.7) 6.6 (3.4) 7.6 (2.6) 9.2 (3.5) 10.1 (2.7) 7.8 (2.6)

8.7 (1.8) 8.9 (1.7) 8.3 (2.9) 10.8 (2.7) 10.3 (2.3) 8.8 (1.8) 5.3 (2.0) 5.1 (2.6) 5.8 (2.4) 7.8 (1.3) 7.3 (2.4) 7.5 (2.8)

Abbreviations: WAIS-III = The Wechler Adult Intelligence Scale-III, FSIQ = full scale intelligence quotient, VIQ = verbal intelligence quotient, PIQ = performance intelligence quotient, VCI = verbal comprehension index, POI = perceptual organization index, WMI = working memory index, and PSI = processing speed index *p<0.05, by Wilcoxon rank sum test

well in settings requiring visual-spatial manipulation and, as a result, they had lower performance ability and VIQ/PIQ discrepancy (Figure 1). Previous reports show that subtests of picture completion, block design, and picture arrangement are sensitive in detecting cognitive dysfunctions in chronic alcoholics [21]. Similarly, our study patients in the discrepancy group also had signifcantly poorer performance (p < 0.05) on these visual-spatial subtests, but digit symbolcoding, another sensitive test to detect cognitive

deficits in alcoholics, did not exhibit any signifcantly differences between the discrepancy and non-discrepancy sub-groups (Table 3). This lack of difference is likely to be due to an overall deficiency on the digit symbol-coding tasks among the subjects and consequently, performance on the subtest is not different between the two subgroups.
The explanations for the vulnerability to cognitive deficits among chronic alcohol abusers in the literature consist of right hemisphere abnor-

Huang MC, Chen CH, Chiou YL, et al. • 197 •

Figure 1.ɹThe frequency of abnormal discrepancies between VIQ and PIQ, VCI and POI, and WMI and PSI, as defined by difference in score greater than 15, 17, and 21, respectively, among Taiwanese norms (gray) and alcoholic patients (black). Abbreviations: VIQ, verbal intelligence quotient; PIQ, performance intelligence quotient; VCI, verbal comprehension index; POI, perceptual organization index; WMI, working memory index; and PSI, processing speed index.

mality, generalized brain dysfunction, frontal lobe vulnerability, and neurotransmitter system disruption [22]. As stated earlier, the patients in this study tended to suffer from signifcantly poorer performance (p < 0.05) on visuo-spatial subtests (Table 3). The right hemisphere is known for its role in coordinating interactions with the three-dimensional world, such as visuo-spatial cognition. The greater impairment in processing non-verbal visuo-spatial material than verbal material in patients with alcoholism leads to speculation that they are more vulnerable to right-hemisphere abnormalities [7, 23]. Few studies are found to focus on the neuro-anatomic significance of the assessment results of WAIS-III. For example, positron emission tomography study shows that the perfor-

mance subtests of WAIS indicate the function of the right posterior parietal region [24]. Similarly, CT scan data reveal that visuo-spatial impairment is associated with lesions of the posterior right hemisphere, cerebellum, or brain stem [25]. In addition, MRI studies have exhibited the relationship between perceptual organization and cerebellar volume [26] as well as the relationship between block design and brain shrinkage [11]. Taken together, these observations suggest that decreased visuo-spatial ability associated with right hemisphere abnormalities may be involved in chronic alcohol use.
The correlations with neuropsychological deficits in alcoholics have been widely investigated, but it is not easy to identify clinical parameters

• 198 • Discrepancy of WAIS-III Scores in Alcoholics

associated with the deficits such as chronicity of alcohol use [21], alcohol withdrawal symptoms [27, 28] or withdrawal seizures [29]. Inter-individual differences in vulnerability to alcohol-induced brain damage may account for the failure to explore the correlation of alcohol-related neuropsychological deficits [30]. In this study, we found that the presence of abnormal VIQ/PIQ or VCI/ POI discrepancies not signifcantly correlated with demographic characteristics, quantity of drinking, age of alcohol dependence, and adverse consequences of alcohol drinking (Table 2).
Three possibilities can explain the failure to discover the association between pertinent parameters and neuropsychological deficits. First, the self-reported information of quantity and frequency of alcohol use and alcohol-related variables may be biased. Second, the attribution of neuropsychological deficits to drinking per se may be overestimated while other developmental or medical risk factors are neglected. Third, premorbid brain dysfunction has been previously reported as a risk factor of alcoholism [31]. Thus, the discrepancy itself may be a premorbid characteristic instead of a consequence of alcohol-related neurotoxicity.
To generalize the results derived from this study data should be with caution because this study has five limitations. First, this study was cross-sectional in design and the sample size was small. A future study with bigger sample size is needed to represent Taiwanese patients with alcohol dependence. Second, we did not assess frontal or prefrontal lobe functions specifically. Thus, we did not have important information of their correlation with subtests in WAIS-III data [3, 32]. Third, administering WAIS-III to the study patients was done, 8 to 26 days after detoxification. The length of the time interval is not long enough to detect “real” deficits in alcoholic because since

neuropsychological dysfunctions may be reversed if the abstinence period is longer [9, 33]. Contrariwise, some reports show that PIQ, which is more vulnerable to long-term heavy drinking, does not recover as quickly or as well as VIQ [19, 21, 30]. Therefore, the VIQ/PIQ discrepancy could possibly exist even if alcoholic subjects which have stayed in abstinence from alcohol longer. Fourth, the use of benzodiazepine in our study could cause cognitive impairment [34] and may have confounded the results. A recent study shows that lorazepam, a benzodiazepine used for detoxifying patients, selectively affects visual perceptual abilities in healthy volunteers [35]. Hence, the potential impact of benzodiazepine on lowering PIQ scores may exist in our study subjects. But the dosages of total lorazepam and trazodone did not differ signifcantly between the discrepancy and non-discrepancy groups (data not shown). Therefore, drug effects between the two groups are considered comparable. Lastly, we did not use any structured or semi-structured interview to ascertain the validity of subjects with pertinent psychiatric diagnoses and we did not recruit subjects in the control group, Future studies are needed to address those five limitations.
In conclusion, recently detoxified Han Taiwanese male alcoholics in this study were found to be likely to have lower PIQ scores compared to the general population. A subgroup of alcoholics in this study showed abnormal discrepancy between VIQ and PIQ, and this impairment can be attributed to visuo-spatial deficits. No drinking variables existed to be associated with the development of abnormal VIQ/PIQ or VCI/ POI discrepancies. In the future, we need longitudinal cohort studies with larger sample sizes, particularly including control subjects for more objective comparison, and with neuroimage evidences to definitely determine whether this

Huang MC, Chen CH, Chiou YL, et al. • 199 •

neuropsychological deficit is a premorbid characteristic or a consequence of alcohol drinking.
Acknowledgements
This study was supported by grants from the Taipei City Government (TCH 95001-62-023 and TCH97001-62-024) and the National Science Council (NSC 93-2314-B-532-005, NSC 95-2314B-532-009-MY3 and 97-2314-B-532-001-MY3).
References
1. Parsons OA, Nixon SJ: Neurobehavioral sequelae of alcoholism. Neurol Clin 1993;11:205-18.
2. Tapert SF, Brown GG, Kindermann SS, et al.: fMRI measurement of brain dysfunction in alcohol-dependent young women. Alcohol Clin Exp Res 2001;25: 236-45.
3. Adams KM, Gilman S, Koeppe RA, et al.: Neuropsychological deficits are correlated with frontal hypometabolism in positron emission tomography studies of older alcoholic patients. Alcohol Clin Exp Res 1993;17:205-10.
4. Beatty WW, Katzung VM, Moreland VJ, Nixon SJ: Neuropsychological performance of recently abstinent alcoholics and cocaine abusers. Drug Alcohol Depend 1995;37:247-53.
5. Brandt J, Butters N, Ryan C, Bayog R: Cognitive loss and recovery in long-term alcohol abusers. Arch Gen Psychiatry 1983;40:435-42.
6. Eckardt MJ, Parker ES, Noble EP, Pautler CP, Gottschalk LA: Changes in neuropsychological performance during treatment for alcoholism. Biol Psychiatry 1979;14:943-54.
7. Sullivan EV, Rosenbloom MJ, Pfefferbaum A: Pattern of motor and cognitive deficits in detoxified alcoholic men. Alcohol Clin Exp Res 2000;24: 611-21.
8. Wechsler D: WAIS-III Administration and Scoring Manual. San Antonio, Texas, USA: The Psychological Corporation,1997.

9. Grant I, Adams KM, Reed R: Aging, abstinence, and medical risk factors in the prediction of neuropsychologic deficit among long-term alcoholics. Arch Gen Psychiatry 1984;41:710-8.
10. Fein G, Torres J, Price LJ, Di Sclafani V: Cognitive performance in long-term abstinent alcoholic individuals. Alcohol Clin Exp Res 2006;30:1538-44.
11. Schottenbauer MA, Momenan R, Kerick M, Hommer DW: Relationships among aging, IQ, and intracranial volume in alcoholics and control subjects. Neuropsychology 2007;21:337-45.
12. Chen CC, Lu RB, Chen YC, et al.: Interaction between the functional polymorphisms of the alcoholmetabolism genes in protection against alcoholism. Am J Hum Genet 1999;65:795-807.
13. Matsushita S, Kato M, Muramatsu T, Higuchi S: Alcohol and aldehyde dehydrogenase genotypes in Korsakoff syndrome. Alcohol Clin Exp Res 2000;24: 337-40.
14. Chen Y, Chen H: Wechsler Adult Intelligence ScaleThird Edition (WAIS-III) Manual for Taiwan. Taipei, Taiwan: The Chinese Behavioral Science Corporation, 2002.
15. Kaufman AS, Lichtenberger EO: Essentials of WAISIII Assessment. New York: John Wiley & Sons, 1999.
16. Becker JT, Butters N, Hermann A, D'Angelo N: A comparison of the effects of long-term alcohol abuse and aging on the performance of verbal and nonverbal divided attention tasks. Alcohol Clin Exp Res. 1983;7:1983:213-9.
17. Harris CR, Albaugh B, Goldman D, Enoch MA: Neurocognitive impairment due to chronic alcohol consumption in an American Indian community. J Stud Alcohol 2003;64:458-66.
18. Kapur N, Butters N: Visuoperceptive deficits in longterm alcoholics and alcoholics with Korsakoff's psychosis. J Stud Alcohol 1977;38:2025-35.
19. Leber WR, Jenkins RL, Parsons OA: Recovery of visual-spatial learning and memory in chronic alcoholics. J Clin Psychol 1981;37:192-7.
20. Wegner AJ, Günthner A, Fahle M: Visual performance and recovery in recently detoxified alcoholics.

• 200 • Discrepancy of WAIS-III Scores in Alcoholics

Alcohol Alcohol. 2001;36:171-9. 21. Beatty WW, Tivis R, Stott H, Nixon SJ, Parsons OA:
Neuropsychological deficits in sober alcoholics: influences of chronicity and recent alcohol consumption. Alcohol Clin Exp Res 2000;24:149-54. 22. Oscar-Berman M, Marinkovic K: Alcoholism and the brain: an overview. Alcohol Res Health 2003;27: 125-33. 23. Drake AI, Hannay HJ, Gam J: Effects of chronic alcoholism on hemispheric functioning: an examination of gender differences for cognitive and dichotic listening tasks. J Clin Exp Neuropsychol 1990;12: 781-97. 24. Chase TN, Fedio P, Foster NL, et al.: Wechsler Adult Intelligence Scale performance: Cortical localization by fluorodeoxyglucose F18-positron emission tomography. Arch Neurol 1984;41:1244-7. 25. Ruessmann K, Sondag HD, Beneicke U: Visuospatial disorders and related lesions of the brain. Int J Neurosci 1989;46:123-6. 26. Posthuma D, Baaré WF, Hulshoff Pol HE, et al.: Genetic correlations between brain volumes and the WAIS-III dimensions of verbal comprehension, working memory, perceptual organization, and processing speed. Twin Res 2003;6:131-9. 27. Glenn SW, Parsons OA, Sinha R, Stevens L: The effects of repeated withdrawal from alcohol on the memory of male and female alcoholics. Alcohol Alcohol 1988;23:337-42.

28. Duka T, Townshend JM, Collier K, Stephens DN: Impairment in cognitive functions after multiple detoxifications in alcoholic inpatients. Alcohol Clin Exp Res 2003;27:1563-72.
29. Tarter RE, Goldstein G, Alterman A, Petrarulo EW, Elmore S: Alcoholic seizures: intellectual and neuropsychological sequelae. J Nerv Ment Dis 1983;171: 123-5.
30. Parsons OA: Neurocognitive deficits in alcoholics and social drinkers: a continuum? Alcohol Clin Exp Res 1998;22:954-61.
31. Deckel AW, Bauer L, Hesselbrock V: Anterior brain dysfunctioning as a risk factor in alcoholic behaviors. Addiction 1995;90:1323-34.
32. Demir B, Uluğ B, Lay Ergün E, Erbaş B: Regional cerebral blood flow and neuropsychological functioning in early and late onset alcoholism. Psychiatr Res 2002;115:115-25.
33. Bendszus M, Weijers HG, Wiesbeck G, et al.: Sequential MR imaging and proton MR spectroscopy in patients who underwent recent detoxification for chronic alcoholism: correlation with clinical and neuropsychological data. Am J Neuroradiol 2001;22: 1926-32.
34. Stewart SA: The effects of benzodiazepines on cognition. J Clin Psychiatry 2005;66:9-13.
35. Pompéia S, Pradella-Hallinan M, Manzano GM, Bueno OF: Effects of lorazepam on visual perceptual abilities. Hum Psychopharmacol 2008;23:183-92.
StudyAlcoholicsPatientsDiscrepanciesPerformance