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Biomedical subjects

M G Aman

Publications and source records attributed to M G Aman.

At least 55 records · Page 3Linked to original sources
PubMed1987

The aberrant behavior checklist: factor structure and the effect of subject variables in American and New Zealand facilities.

The Aberrant Behavior Checklist was used to collect data from a large United States institution for comparison with ratings previously obtained in New Zealand. A total of 531 subjects within the American facility and 937 residents of New Zealand institutions were studied. The United States data were factor analyzed using the same procedures that were employed to develop the scale in New Zealand. In addition, subscales of the Checklist were analyzed as a function of sex, age, country, and level of mental retardation. Finally, the effects of various medical conditions were analyzed. The original factor structure of the Checklist was validated for the United States sample, with a mean coefficient of congruence of .93 averaged across the five factors. Sex failed to influence subscale scores, whereas age, country, and severity of retardation significantly affected ratings. Deafness was unrelated to Checklist scores whereas cerebral palsy, epilepsy, psychosis, and psychoactive drug treatment were related.

Adult↗
PubMed1986

Incidental learning, distraction, and sustained attention in hyperactive and control subjects.

Thirty-two children designated as hyperactive (ADD) were compared with an equal number of control subjects who were matched for age, sex, and verbal IQ. The subjects were tested on a component selection task, measuring serial memory and incidental learning and a cancellation task, assessing attentional variables and distractibility. No straightforward group differences were found on the component selection task, whereas hyperactive subjects made more omission and commission errors than controls on the cancellation task. It was concluded that a deficit in sustained attention and impulsivity best described the group differences. Age was also found to influence performance on a number of variables, including incidental learning on the component selection task and response rate and omission errors on the cancellation task. Because subjects in the hyperactive group were rated as extreme on a number of subscales not necessarily related to hyperactivity, the data were reexamined by multiple regression analyses. Subscales considered to be related both to hyperactivity and to conduct disorder were associated with different performance variables, indicating that each of these subscales provided some unique information.

Age Factors↗
PubMed1986

Preliminary study of imipramine in profoundly retarded residents.

This was a double-blind, placebo-controlled crossover trial of imipramine (3 mg/kg/day) in 10 profoundly retarded residents. Two groups were formulated: one with depressivelike (or affective) symptoms and one with acting-out behaviors. Measures of drug response included ratings of ward behavior using the Aberrant Behavior Checklist, interval samples of behavior in the living units, and observations of behavior in a playroom situation. Results indicated that the drug caused behavioral deterioration in the Irritability, Lethargy/social withdrawal, and Hyperactivity dimensions of the rating scale, irrespective of subgroup. In addition, gross motor activity was significantly increased on the wards due to imipramine, and it was found that the affective group became less active and the acting-out group more active during free play. Physical side effects were uncommon. These unexpected adverse behavioral effects were discussed with respect to dosage and diagnostic considerations.

Acting Out↗
PubMed1986

A single-subject study of imipramine in a mentally retarded woman with depressive symptoms.

A double-blind, placebo-controlled, reversal design was used to assess imipramine. The subject was a young woman, with moderate mental retardation, whose salient clinical characteristics included weight loss, episodes of screaming and crying, agitation, and generally high levels of irritable behaviour. As compared with placebo, 100 mg of imipramine resulted in consistent improvement in terms of increased food consumption, decreases in screaming and crying, and stabilized sleep. Drug effects were fairly specific and a number of other clinical variables were unaffected by treatment. There was no evidence that imipramine impaired cognitive functioning as assessed by IQ performance.

Adult↗
PubMed1986

A critical appraisal of recent drug research in mental retardation: the Coldwater studies.

This paper attempts to assess public and professional attitudes toward drug treatment in mental retardation and concludes that considerable sentiment has developed in recent years against the use of pharmacotherapy. A number of factors contributing to this prevailing attitude were identified and discussed. In particular, a series of investigations carried out by researchers at the Coldwater Regional Center for Developmental Disabilities (Michigan), which have had negative implications for drug treatment, were summarized. These studies have suggested that psychotropic drugs, especially the antipsychotics, may adversely affect clinical management of mentally retarded persons, depress learning performance, and interfere with the efficacy of reinforcement contingencies. However, certain features of these studies, such as the procedures for selecting subjects, the doses utilized and overall guiding philosophy, appear to limit their relevance. Balanced against these are a number of other investigations showing circumscribed positive clinical effects, a lack of interference with learning and little or no disruption of reinforcement contingencies. It was concluded that all-encompassing judgments about the value of pharmacotherapy in mentally retarded people are premature at this time. We suggested that a major objective of clinical drug research should be to look for enhancement of adaptive functioning by discovering appropriate subject-treatment combinations, while remaining vigilant for adverse effects.

Aggression↗
PubMed1986

Prevalence of toxic anticonvulsant drug concentrations in mentally retarded persons with epilepsy.

Anticonvulsant drug concentrations in retarded individuals (117 hospital residents, 58 community-based) were surveyed. Concentrations of carbamazepine (CBZ, Tegretol) and phenytoin (Dilantin) were determined in salivary samples collected before morning medication (premedication sample) and 4 hours later (postmedication sample). Of 146 individuals receiving CBZ, 16% had salivary concentrations above the therapeutic range on at least one sample, whereas 2% exceeded the range on both samples. Of the 54 subjects prescribed phenytoin, 28% had at least one salivary concentration exceeding the therapeutic range, and 15% surpassed the therapeutic range on both samples. These data suggest the desirability of using regular therapeutic drug monitoring and neurological assessments to avoid the possibility of toxic drug levels in this population. A variety of subject and pharmacological variables (sex, severity of retardation, number of seizures in the last year, and dose) were also examined for their relationship to drug concentrations.

Adult↗
PubMed1985

City-wide survey of drug patterns among non-institutionalized mentally retarded persons.

This was a survey of 1,012 non-institutionalized mentally retarded persons living in a medium-sized metropolitan area. The sample was drawn from special schools and two service agencies in Auckland that serve preschool and adult retarded people. These are the main organizations serving this population in Auckland, and collectively they include a large proportion of non-institutionalized retarded individuals in this city. A comprehensive summary of current medication was obtained for each subject. A variety of demographic, medical, social, and sleep data were collected and, where appropriate, information was gathered regarding time elapsed since the last seizure. Two percent of preschoolers, 3% of special school students, and 14% of adults were receiving psychotropic drugs. Anticonvulsant drugs were prescribed for 31% of preschoolers, 17% of special school cases, and 18% of the adults. A large proportion of the demographic, medical, and social/sleep variables were associated with drug prescription patterns. These factors were discussed with respect to other surveys, and possible explanations were offered to account for their relationship to pharmacotherapy.

Adolescent↗
PubMed1985

Dyskinetic symptoms in profoundly retarded residents following neuroleptic withdrawal and during methylphenidate treatment.

This is a between-groups comparison of chronic drug therapy in profoundly retarded residents. One group of residents received maintenance antipsychotic medication before the study, whereas the control group had been drug-free. Both groups were assessed for dyskinetic symptoms at ten weekly intervals as dosage was phased out in the neuroleptic group. During weeks seven to nine, a double blind, placebo controlled, crossover trial of methylphenidate (Ritalin) took place. Although the original purpose of this was to determine whether methylphenidate helped to suppress chronic behaviour problems, its effects on dyskinetic symptoms were studied as well. Dyskinetic symptoms were marginally higher within the neuroleptic group but they increased strikingly over time irrespective of group membership. Drug consumption, expressed in terms of chlorpromazine equivalents and effect on the dopamine system, was found to be associated with total dyskinetic symptoms at one of two follow-up intervals. Methylphenidate caused a significant increase in dyskinesia scores but this occurred on a minority of subscales.

Adolescent↗
PubMed1985

Pimozide treatment in disruptive severely retarded patients.

Eight severely retarded residents took part in a double blind, placebo controlled trial of pimozide. The drug did not alter behavioural adjustment as assessed by behaviour observations. However, ratings on a standardised checklist of aberrant behaviour showed significant drug-induced improvements on two dimensions (Irritability and Hyperactivity/non-compliance). Learning performance, as assessed by a discrimination learning task, was not affected by the drug.

Adolescent↗
PubMed1985

Psychometric characteristics of the aberrant behavior checklist.

Information was presented on the psychometric characteristics of the Aberrant Behavior Checklist. The internal consistency and test-retest reliability of the Checklist appeared to be very good. Interrater reliability tended to vary across raters and subscales and ranged from mediocre to good but was generally in the moderate range and acceptable for research purposes. Validity was assessed by comparing Checklist scores for residents presenting with attributes thought to reflect varying degrees of social adaptation. Validity was also evaluated by comparing Aberrant Behavior Checklist scores with ratings on adaptive behavior scales and with objective observations of behavior. In general, validity was established for most Aberrant Behavior Checklist subscales. Preliminary data from drug investigations suggested that the Checklist may provide a useful adjunct for the assessment of psychotropic drug effects.

Adolescent↗
PubMed1985

The aberrant behavior checklist: a behavior rating scale for the assessment of treatment effects.

The development of a scale to assess drug and other treatment effects on severely mentally retarded individuals was described. In the first stage of the project, an initial scale encompassing a large number of behavior problems was used to rate 418 residents. The scale was then reduced to an intermediate version, and in the second stage, 509 moderately to profoundly retarded individuals were rated. Separate factor analyses of the data from the two samples resulted in a five-factor scale comprising 58 items. The factors of the Aberrant Behavior Checklist have been labeled as follows: (I) Irritability, Agitation, Crying; (II) Lethargy, Social Withdrawal; (III) Stereotypic Behavior; (IV) Hyperactivity, Noncompliance; and (V) Inappropriate Speech. Average subscale scores were presented for the instrument, and the results were compared with empirically derived rating scales of childhood psychopathology and with factor analytic work in the field of mental retardation.

Adult↗
PubMed1984

Hyperactivity: nature of the syndrome and its natural history.

The composition of hyperactivity as a syndrome is discussed from a historical perspective, and the principal events leading to the recent emphasis on attentional characteristics of hyperactive children are summarized. Some of the major challenges to the legitimacy of hyperactivity as a valid syndrome are set forth, and after critical examination of the most influential work, it is concluded that hyperactivity has not been disproved. This is followed by a survey of the large follow-up literature dealing with the natural history of children diagnosed as hyperactive. It is noted that the manifestations of the syndrome appear to change with age but there is little indication that problems simply remit with maturity. The evidence indicates that hyperactivity, as diagnosed in the past, is often a serious disorder with long-term and far-reaching consequences for the children and their families. Multivariate studies are also discussed, as they have important implications for differential outcome. Different symptoms such as aggression, overactivity, and learning disability appear to contain unique information about current and future status, and therefore it appears useful to retain these distinctions rather than view such children as part of an undifferentiated group. It is unknown whether the recent guidelines for diagnosing Attention Deficit Disorder with Hyperactivity will alter or refine the outlook for children so identified, but this is an active area of research at present.

Adolescent↗
PubMed1984

Chlorpromazine effects on stereotypic and conditioned behaviour of severely retarded patients--a pilot study.

An attempt was made to test the hypothesis that anti-psychotic medication may induce adaptive changes by suppressing stereotypic behaviour. Six profoundly retarded residents were selected for the presence or absence of stereotypic behaviour and tested in a placebo controlled, cross-over study. Chlorpromazine caused noticable drowsiness in all subjects over the 2-week drug period. Body rocking was significantly suppressed in the wards, but other clinical behaviours were not influenced by the drug. Performance on an operant conditioning task was significantly impaired in most subjects. Body rocking, which was also assessed during operant responding, was unrelated to presence or absence of clinical stereotypy, observed on the wards. The results were discussed in terms of chlorpromazine's clinical effects and improved ways of assessing the hypothesis that anti-psychotic drugs may enhance adaptive behaviour in some retarded individuals.

Acting Out↗
PubMed1984

Mechanism for testing operant conditioning and body rocking in developmental disabilities.

A mechanism is described for testing operant conditioning and body rocking in developmentally disabled persons. The system is made up of a reinforcement dispenser, a lever-pulling mechanism, and flexible chair back for testing body rocking. Experience with the system has shown it to be sturdy and reliable, and the reinforcement dispenser to be adaptable to a wide range of food preferences.

Conditioning, Operant↗
PubMed1984

Effects of methylphenidate in normal adults with reference to drug action in hyperactivity.

Methylphenidate was administered to each of 12 adult volunteers in a double-blind, placebo-controlled, crossover study for purposes of comparison with previous studies in hyperactive children. Statistically significant changes occurred only on a minority of measures, but the results were generally in the direction of facilitated performance, reduced physical activity and increased emotional responsivity. As these results are similar to those in hyperactive and normal children, this appears to support the contention that stimulant drug effects in hyperactive children are not paradoxical or atypical.

Adult↗
PubMed1983

Factor structure and norms for the Revised Behavior Problem Checklist in New Zealand children.

The Revised Behavior Problem Checklist (RBPC) is a recent expansion of the widely used Behavior Problem Checklist. This study attempted to replicate the factor structure of the RBPC, originally developed for U.S.A. children, and to establish norms for its use with New Zealand children. Two groups of children, aged five to 13 years, were rated on the scale by their parents. One was a clinic sample and comprised 266 patients attending two psychiatric clinics. The second was a random community sample of 267 children, from four census tracts in Auckland, selected to cover a range of socioeconomic strata representative of New Zealand. Factor analysis of the clinic data resulted in a factor structure similar to that found in American children. Only two of the six factors (Socialised Aggression and Psychotic Behaviour) differed to any degree. Using ratings from the community sample, norms were developed for screening and diagnostic purposes.

Adolescent↗
PubMed1983

Fluctuations in salivary carbamazepine and carbamazepine-10,11-epoxide concentrations during the day in epileptic children.

Hourly salivary concentrations of carbamazepine (CBZ) and carbamazepine-10,11-epoxide (EP) were studied during 2 consecutive days in a group of epileptic children receiving twice daily CBZ monotherapy either as the tablet or syrup formulation. Relatively large fluctuations were observed for both CBZ (mean, 57%; range, 32-100%) and EP (mean, 97%; range, 19-189%) during a dosage interval. However, concentrations of EP were generally much lower, approximately 34% of corresponding CBZ levels, and in absolute terms the concentration-time curves for EP appeared much less variable. Further evidence supporting extensive CBZ concentration fluctuations during the day was provided by an additional group of 30 epileptic children receiving CBZ monotherapy whose time of dosage was manipulated to achieve peak and trough concentrations during assessment with a psychomotor test battery. Changes in salivary CBZ concentrations within subjects ranged from 4 to 272% (median, 65%), excluding two atypical cases who showed greater than 10-fold increases in the expected high concentration. These results suggest that in children there is a substantial risk of error in the interpretation of CBZ concentrations from a single sample without consideration of the time of last dose. The implications of these findings for clinical treatment with regard to the appearance of side effects and changes in psychomotor function are discussed.

Adolescent↗