Reduction of stimulus overselectivity with nonverbal differential observing responses.
(1/993)
Three individuals with mental retardation exhibited stimulus overselectivity in a delayed matching-to-sample task in which two sample stimuli were displayed on each trial. Intermediate accuracy scores indicated that participants could match one of the samples but not both of them. Accuracy in a baseline condition was compared to accuracy with a differential observing response procedure. This procedure prompted participants to make simultaneous identity-matching responses that required observation and discrimination of both sample stimuli. These observing responses were never followed by differential consequences. When observing responses were prompted, participants' accuracy scores improved. In a return to the baseline condition, when differential observing responses were no longer prompted, accuracy returned to intermediate levels. The results show that stimulus overselectivity can be greatly reduced by a behavioral intervention that controls observing behavior and verifies discrimination, but that exposure to such procedures alone may be insufficient for lasting benefits. (+info)
Lack of benefit of a single dose of synthetic human secretin in the treatment of autism and pervasive developmental disorder.
(2/993)
BACKGROUND: Secretin is a peptide hormone that stimulates pancreatic secretion. After recent publicity about a child with autism whose condition markedly improved after a single dose of secretin, thousands of children with autistic disorders may have received secretin injections. METHODS: We conducted a double-blind, placebo-controlled trial of a single intravenous dose of synthetic human secretin in 60 children (age, 3 to 14 years) with autism or pervasive developmental disorder. The children were randomly assigned to treatment with an intravenous infusion of synthetic human secretin (0.4 microg per kilogram of body weight) or saline placebo. We used standardized behavioral measures of the primary and secondary features of autism, including the Autism Behavior Checklist, to assess the degree of impairment at base line and over the course of a four-week period after treatment. RESULTS: Of the 60 children, 4 could not be evaluated - 2 received secretin outside the study, and 2 did not return for follow-up. Thus, 56 children (28 in each group) completed the study. As compared with placebo, secretin treatment was not associated with significant improvements in any of the outcome measures. Among the children in the secretin group, the mean total score on the Autism Behavior Checklist at base line was 59.0 (range of possible values, 0 to 158, with a larger value corresponding to greater impairment), and among those in the placebo group it was 63.2. The mean decreases in scores over the four-week period were 8.9 in the secretin group and 17.8 in the placebo group (mean difference, -8.9; 95 percent confidence interval, -19.4 to 1.6; P=0.11). None of the children had treatment-limiting adverse effects. After they were told the results, 69 percent of the parents of the children in this study said they remained interested in secretin as a treatment for their children. CONCLUSIONS: A single dose of synthetic human secretin is not an effective treatment for autism or pervasive developmental disorder. (+info)
Effects of a fixed-time schedule on aberrant and adaptive behavior.
(3/993)
Fixed-time (FT) schedules of reinforcement have been used to decrease destructive behavior. However, the effects of FT schedules on acquisition and maintenance of appropriate behavior remain unclear. In this study, we present a case in which an FT schedule produced an increase in adaptive behavior and resulted in a significant decrease in destructive behavior. (+info)
A population-based study of measles, mumps, and rubella vaccination and autism.
(4/993)
BACKGROUND: It has been suggested that vaccination against measles, mumps, and rubella (MMR) is a cause of autism. METHODS: We conducted a retrospective cohort study of all children born in Denmark from January 1991 through December 1998. The cohort was selected on the basis of data from the Danish Civil Registration System, which assigns a unique identification number to every live-born infant and new resident in Denmark. MMR-vaccination status was obtained from the Danish National Board of Health. Information on the children's autism status was obtained from the Danish Psychiatric Central Register, which contains information on all diagnoses received by patients in psychiatric hospitals and outpatient clinics in Denmark. We obtained information on potential confounders from the Danish Medical Birth Registry, the National Hospital Registry, and Statistics Denmark. RESULTS: Of the 537,303 children in the cohort (representing 2,129,864 person-years), 440,655 (82.0 percent) had received the MMR vaccine. We identified 316 children with a diagnosis of autistic disorder and 422 with a diagnosis of other autistic-spectrum disorders. After adjustment for potential confounders, the relative risk of autistic disorder in the group of vaccinated children, as compared with the unvaccinated group, was 0.92 (95 percent confidence interval, 0.68 to 1.24), and the relative risk of another autistic-spectrum disorder was 0.83 (95 percent confidence interval, 0.65 to 1.07). There was no association between the age at the time of vaccination, the time since vaccination, or the date of vaccination and the development of autistic disorder. CONCLUSIONS: This study provides strong evidence against the hypothesis that MMR vaccination causes autism. (+info)
Autism: a medical primer.
(5/993)
Autistic disorder, a pervasive developmental disorder resulting in social, language, or sensorimotor deficits, occurs in approximately seven of 10,000 persons. Early detection and intervention significantly improve outcome, with about one third of autistic persons achieving some degree of independent living. Indications for developmental evaluation include no babbling, pointing, or use of other gestures by 12 months of age, no single words by 16 months of age, no two-word spontaneous phrases by 24 months of age, and loss of previously learned language or social skills at any age. The differential diagnosis includes other psychiatric and pervasive developmental disorders, deafness, and profound hearing loss. Autism is frequently associated with fragile X syndrome and tuberous sclerosis, and may be caused by lead poisoning and metabolic disorders. Common comorbidities include mental retardation, seizure disorder, and psychiatric disorders such as depression and anxiety. Behavior modification programs are helpful and are usually administered by multidisciplinary teams, targeted medication is used to address behavior concerns. Many different treatment approaches can be used, some of which are unproven and have little scientific support. Parents may be encouraged to investigate national resources and local support networks. (+info)
Sleep patterns of children with pervasive developmental disorders.
(6/993)
Data on sleep behavior were gathered on 100 children with pervasive developmental disorders (PDD), ages 2-11 years, using sleep diaries, the Children's Sleep Habits Questionnaire (CSHQ), and the Parenting Events Questionnaire. Two time periods were sampled to assess short-term stability of sleep-wake patterns. Before data collection, slightly more than half of the parents, when queried, reported a sleep problem in their child. Subsequent diary and CSHQ reports confirmed more fragmented sleep in those children who were described by their parents as having a sleep problem compared to those without a designated problem. Interestingly, regardless of parental perception of problematic sleep, all children with PDD exhibited longer sleep onset times and greater fragmentation of sleep than that reported for age-matched community norms. The results demonstrate that sleep problems identified by the parent, as well as fragmentation of sleep patterns obtained from sleep diary and CSHQ data, exist in a significant proportion of children with PDD. (+info)
Pathological demand avoidance syndrome: a necessary distinction within the pervasive developmental disorders.
(7/993)
A proposal is made to recognise pathological demand avoidance syndrome (PDA) as a separate entity within the pervasive developmental disorders, instead of being classed under "pervasive developmental disorder not otherwise specified" (PDDnos, DSM-IV). Discriminant functions analysis shows PDA to be significantly different on many counts from classic autism and Asperger's syndrome, both separately and together, including an equal sex ratio (150 cases). Demand avoidance using social manipulation is seen in all children, which strongly contrasts with the features of autistic spectrum disorders. A criterial structure is described, supported by statistical data from a random sample of 50 children diagnosed with PDA, together with a follow up sample of 18 young adults. (+info)
Is fever suppression involved in the etiology of autism and neurodevelopmental disorders?
(8/993)
BACKGROUND: There appears to be a significant increase in the prevalence rate of autism. Reasons for the increase are unknown, however, there is a substantial body of evidence that suggests the etiology involves infections of the pregnant mother or of a young child. Most infections result in fever that is routinely controlled with antipyretics such as acetaminophen. The blocking of fever inhibits processes that evolved over millions of years to protect against microbial attack. Immune mechanisms in the central nervous system are part of this protective process. HYPOTHESIS: The blockage of fever with antipyretics interferes with normal immunological development in the brain leading to neurodevelopmental disorders such as autism in certain genetically and immunologically disposed individuals. TESTING THE HYPOTHESIS: Epidemiological studies to determine associations between the use of antipyretics and neurodevelopmental disorders should be undertaken. Biochemical tests will involve the examination of fluids/serum by mass spectrometry and the determination of cytokine/chemokine levels in serum and cell culture fluids after stimulation with fever-inducing molecules from bacteria, viruses and yeast. Postmortem brain can be examined by immunohistochemistry or other methods such as fluorescent in situ hybridization (FISH) to determine altered expression levels of chemokines/cytokines and other molecules. IMPLICATIONS OF THE HYPOTHESIS: 1) The use of antipyretics during pregnancy or in young children may be reserved for more severe fevers. 2) The perplexing genetic findings in autism may be better understood by categorizing genes along functional pathways. 3) New treatments based on immune, cell, pharmacological or even heat therapies may be developed. (+info)