The test-retest reliability and stability of the WAIS-R in a sample of mentally retarded adults

ABSTRACT. Fifty mentally retarded adults were administered the Wechsler Adult Intelligence Scale-Revised (WAIS-R) on two separate occasions, with the mean amount of time between testings being 2 years, 8 months. The data were examined in an effort to study the test-retest reliability and stability of the WAIS-R with the mentally retarded. Based on correlational, t -value and percentage of scale score change information, the authors concluded that the WAIS-R IQs appeared to possess good test-retest reliability and stability over an approximate 2–5 year period for the present sample of mentally retarded adults.     

Comparison of WAIS and WAIS-R scores of mildly and moderately mentally retarded adults

The Wechsler Adult Intelligence Scale (WAIS) and the Wechsler Adult Intelligence Scale-Revised (WAIS-R) were administered to 29 mildly and moderately mentally retarded adults. The WAIS Verbal and Full Scale IQs were significantly lower than were corresponding WAIS-R IQs. This difference is an exception to the general pattern of IQs being higher for tests that were standardized earlier. The present results suggest that WAIS-R IQs will be much higher than WISC-R IQs.     

WAIS-R short forms with mentally retarded adults: a note of caution

ABSTRACT. In summary, the authors found that both selected-subtest and selected-items short forms were highly correlated with the WAIS-R data. Nevertheless, neither method met the t-test and ≤3-point IQ criteria. Therefore, the short forms examined here do not appear to be valid measures in assessing the intellectual functioning of mentally retarded adults.     

Differential WAIS/WAIS-R IQ discrepancies among institutionalized mentally retarded persons

Compared to the Wechsler Adult Intelligence Scale, the Wechsler Adult Intelligence Scale-Revised (WAIS-R) is generally reported to result in IQs that are somewhat lower for nonretarded subjects and unchanged for retarded subjects. In the present study these findings were replicated with subjects in a residential treatment center, except that the moderately retarded subgroup demonstrated significantly higher WAIS-R IQs (mean increase of 6 points in Full Scale IQ), with reclassification as mildly mentally retarded possible for 64% of these persons. Such differential, level-specific effects require careful interpretation of WAIS-R IQs of retarded persons in the context of actual adaptive skills.     

Social judgment and vocational adjustment of mentally retarded adults

Two studies dealing with interpersonal judgments of mildly mentally retarded adults were carried out. In the first study, mentally retarded adults referred for vocational evaluation were found to be significantly less able to discriminate accurately between adept and inept vocationally-relevant social problem-solving tactics than were physically handicapped and mentally ill adults. In the second study, mentally retarded adults with good vocational adjustment were found to have significantly better interpersonal judgment than individuals of equal IQ but with poor vocational adjustment. These results suggest that social judgment level may be an important contributor to work success of mentally retarded adults, and that greater attention should be paid to this variable by vocational rehabilitation professionals.     

Referential first mention in narratives by mildly mentally retarded adults

Referential first mentions in narrative reports of a short film by 40 mildly mentally retarded adults and 20 nonretarded adults were compared. The mentally retarded sample included equal numbers of male and female, and black and white speakers. The mentally retarded speakers made significantly fewer first mentions and significantly more errors in the form of the first mentions than did nonretarded speakers. A pattern of better performance by black males than by other mentally retarded speakers was found. It is suggested that task difficulty and incomplete mastery of the use of definite and indefinite forms for encoding old and new information, rather than some global type of egocentrism, accounted for the poorer performance by mentally retarded speakers.     

Habituation of optically evoked blink reflex in mentally retarded adults

This study was done to record the difference in habituation patterns of optically evoked blink reflexes in mentally retarded and normal adults. Sets of photic stimuli with fixed interstimulus duration were utilized in normal volunteers and Paperink mentally retarded adults. The interstimulus duration decreased with each sequential set. The blink responses were recorded on fibreoptic recording paper. These electrophysiological methods show objectively that the blink responses to light which habituate in normal adults fail to do so in those who arc mentally retarded.     

Somatomedin C (insulin-like growth factor 1) in adults with Down's syndrome

ABSTRACT. In a Norwegian institution for the mentally retarded, 29 adults with chromosomally verified Down's syndrome were compared to other mentally retarded patients with respect to serum somatomedin C (SmC) (insulin-like growth factor 1 [IGF-1]). Contrary to what has been observed in children, no shortage of SmC could be demonstrated in the adults with Down's syndrome. The results were within the normal range, and there was no difference between those with Down's syndrome and the other mentally retarded patients. Human growth hormone (HGH) and body height were studied in a previous work. Some correlations with these data are, nevertheless, included herein because they are of relevance. SmC correlated with body height in Down's syndrome, while there was no correlation between SmC and HGH or between HGH and body height.     

Comprehension of syntactically indicated sequence by Down's syndrome and other mentally retarded adults

ABSTRACT. The ability to comprehend syntactically ordered sequence by Down's syndrome adults and adults with mental retardation of no specific aetiology was studied. Both samples exhibited patterns of comprehension that resembled those of children who are not mentally retarded. However, the Down's syndrome individuals had significantly more difficulty when sequence was indicated by syntax with no supporting extralinguistic context. The Down's syndrome adults appeared to be arrested at an earlier stage of development than the other mentally retarded adults.     

Classifying mental retardation and specific strength and deficit areas in severe and profoundly mentally retarded persons with the MESSIER

The MESSIER, a measure of social and communication skills and the Vineland Social Maturity Scale were administered to 618 severe and profoundly mentally retarded adults. The goal of the study was to establish the potential utility of the MESSIER for classifying level of intellectual disability in this group. Comparing MESSIER scores to previously established DSM-IV-TR diagnosis, 86% of the severe and 80% of the profoundly mentally retarded persons were correctly classified. The implications of these data in using the MESSIER for classification and treatment planning are discussed.     

Psychosocial correlates of depression in mentally retarded adults: II. Poor social skills

This is the second report on the results of an investigation of the psychosocial correlates of depression in mildly mentally retarded adults. Results of the present study showed that depression was associated with informant ratings of poor social skills. The results of the entire investigation suggest that further research is necessary on the associations among poor social skills, low levels of social support, and the occurrence of depression in mentally retarded adults.     

Relapse of aggressive and disruptive behavior in mentally retarded adults following antipsychotic drug withdrawal predicts psychotropic drug use a decade later

BACKGROUND: Mental retardation is frequently associated with aggression toward self and others. Antipsychotic medications are frequently used as a major treatment of such aggression. However, national and state policies and guidelines are weighted toward stopping or decreasing the doses of these medications whenever possible, although exceptions are permitted. The purpose of this study was to determine if relapse during or after antipsychotic drug withdrawal in mentally retarded adults predicts continuing antipsychotic drug use an average of a decade later. METHOD: We report here on a 6- to 13-year (average 10-year) follow-up of 151 institutionalized mentally retarded adults. During the period 1990-1997, the subjects had been prescribed antipsychotic medications to treat maladaptive behaviors, primarily consisting of aggression, disruptive/destructive behaviors, or a combination of these. We compared subjects' psychotropic medication profiles in 2003 as they related to outcome during the earlier period. Our goal was to determine if rapid relapse (a clinically significant increase in maladaptive target symptoms, beginning 3 months or less after antipsychotic drug termination or dosage reduction, that was reversed by antipsychotic drug reinstitution or dosage increases) during or after routine withdrawal of an antipsychotic predicted psychotropic drug use in 2003. RESULTS: For those individuals successfully withdrawn from antipsychotic medications, 66.3% (55/83) were still psychotropic drug free in 2003. For those who rapidly relapsed during the period 1990-1997 following antipsychotic drug withdrawal or dosage decreases, only 9.0% (5/55) were psychotropic medication free in 2003. CONCLUSION: These observations support policies and guidelines indicating that attempts to stop treatment with antipsychotic medications in mentally retarded individuals are worthwhile. However, the results also indicate that eventual discontinuation of antipsychotic medications in institutionalized mentally retarded adults who have previously relapsed upon such withdrawal is unlikely to be successful. Rigid adherence to drug withdrawal policies and guidelines in such individuals should be reconsidered.     

Phonological process analysis of the speech of mentally retarded adults

A phonological process analysis was performed on the speech of 20 mentally retarded adults. Results indicated that these subjects exhibited deletion of final consonant, cluster reduction, weak syllable deletion, and stopping. These processes are similar to those previously reported for mentally retarded children and unintelligible nonretarded children. Differences between subjects classified as moderately and severely retarded appear to be quantitative rather than in type of process exhibited.     

Subtest profiles of the WISC-R and WAIS in mentally retarded patients with epilepsy

In this study, WISC-R and WAIS subtest profiles of mentally retarded patients with epilepsy are analysed with respect to the Verbal-Performance IQ Discrepancy scores and rank order of mean subtest scores. The relative strengths and weaknesses in cognitive patterns of this sample are compared with subtest profiles mentioned in the literature on mentally retarded populations and samples of normal intelligent patients with epilepsy in order to determine the impact of epilepsy factors on cognition. The results indicate that people with mental retardation have problems with the verbal subtests Arithmetic, Vocabulary and Information, while patients with epilepsy have problems with Coding (Digit Symbol), Digit Span and Information. For this sample of mentally retarded patients with epilepsy, the most difficult subtests are Digit Span and Coding. The results concerning subtest profiles in different populations are discussed in light of the deleterious impact of epilepsy on cognition, which may superimpose the general effect of brain damage in mentally retarded patients. It is suggested that especially attentional processes, as measured with the subtest Coding, are vulnerable for epilepsy factors.     

Sexual attitudes and knowledge of high-functioning adolescents and adults with autism

Interviewed 21 high-functioning adults with autism and 20 mildly to moderately mentally retarded adults without autism about sexuality and dating. Sexual knowledge and interest were assessed by a sexuality vocabulary checklist and a multiple-choice questionnaire. Group differences were found in experience, with more sexual experiences among the mentally retarded adults, but not in knowledge or interest. In both groups IQ was positively correlated with knowledge scores and males had significantly greater interest in sexuality than females. Implications of sex and group differences are discussed.     

Facial expressions of mentally retarded and nonretarded children: I. Recognition by mentally retarded and nonretarded adults

Mentally retarded and nonretarded adults' ability to recognize happiness, anger, sadness, and neutral affect from slides of young mentally retarded and nonretarded children was investigated. Recognizing affects in others is part of social awareness and necessary for successful social interactions. Retarded adults recognized fewer facial expressions than did nonretarded adults. Nonretarded children's expressions were identified more accurately than were those of retarded children. Happiness was recognized best. Retarded adults used the label "happy" most often, whereas nonretarded adults used the label "neutral" most often. Absence of affect (neutral) was recognized least well by retarded adults. Neutral and sad were confounded most often by nonretarded adults, whereas retarded adults confounded angry and sad most often.     

On being called "mentally retarded": do developmental and professional perspectives limit labeling effects?

When children are labeled "mentally retarded," adults sometimes respond to their failures in ways that stimulate learned helplessness. The generalizability of such labeling effects was assessed in this study. Participants were four groups of adults that varied in professional experience with retarded children: within each group, some subjects subscribed to the developmental position (that retarded and nonretarded children have similar reasoning and learning capacities when matched for mental age) and some to the difference position (that retarded children lag behind their nonretarded peers in such capacities even when matched for mental age) of mental retardation. All subjects made judgments about the failure of a "retarded" and an unlabeled child. Strong labeling effects were found among proponents of the difference position but not among proponents of the developmental position, as well as among those groups with relatively little professional experience. Results suggest that beliefs consistent with the developmental position and experience with retarded children both attenuate the potentially helplessness-inducing effects of the mentally retarded label.     

Comparison of mentally retarded and nonretarded persons' organization of semantic memory

The production frequency of exemplars for 16 categories was obtained from institutionalized mentally retarded adults and compared with those of nonretarded children, adolescents, and adults and with typicality ratings given by the same retarded subjects previously. The production frequency of exemplars by retarded and nonretarded persons was remarkably similar and varied more as a function of specific category than of mental development. Production frequency and typicality ratings of the retarded persons were less reliable. There is a striking similarity in the structure of the semantic memory of retarded and nonretarded persons.     

Influences of an analog of the neuropeptide ACTH 4--9 on mentally retarded adults.

In a double-blind procedure, 24 mentally retarded adults received 0 mg, 5mg, or 20 mg of an analog of the neuropeptide ACTH 4--9. Following treatment with peptide, the subjects were given the Trails B Test (from the Halstead-Reitan Neuropsychological Battery), the Peabody Picture Vocabulary test, the Benton Visual Retention Test, a concept-formation task, and a standard orienting sequence. The results of the behavioral tests suggested that attentional processes were enhanced in subjects treated with the peptide. The present study, in conjunction with another investigation using the neuropeptide ACTH/MSH 4--10 (Sandman, George, Walker, Nolan & Kastin, 1976), indicates that attentional deficits in mentally retarded adults, traditionally assumed to be irreversible, may be influenced by treatment with fragments of the neuropeptides ACTH and MSH.     

Vigilance performance of mildly mentally retarded adults

Mildly mentally retarded adults were compared on both an auditory and a visual vigilance task with subjects having greater than average intelligence. Contrary to results reported by Semmel (1965) using a visual task, no difference was found in the rate of decline of performance between the two groups in either of the two tasks, although overall performance of the above-average group was superior to that of the retarded group. The results offered no support for the hypothesis that mentally retarded persons suffer from a more rapid decay in arousal under conditions of reduced sensory variation. Nor did they support a suggestion that in this particular situation retarded subjects would demonstrate more inattention than would nonretarded subjects.