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S R Schroeder

Publications and source records attributed to S R Schroeder.

At least 19 recordsLinked to original sources
PubMed2004

Using the Diagnostic Assessment of the Severely Handicapped-II (DASH-II) to measure the therapeutic effects of risperidone.

BACKGROUND: Within the scope of a double-blind, placebo-controlled, crossover medication study, the Diagnostic Assessment of the Severely Handicapped-II (DASH-II) was evaluated as a measurement for determining the effectiveness of the medication risperidone in treating the problem behaviour of 21 people with intellectual disabilities (ID). METHOD: Participants' caregivers completed the DASH-II during the placebo/baseline phase of the study and the maintenance phase of the study, and completed the Aberrant Behavior Checklist - Community (ABC-C) weekly throughout the entire study. The results obtained using the DASH-II were compared to those obtained using the ABC-C, an instrument shown to be well correlated with the DASH-II. RESULTS: Results suggest that while the DASH-II and the ABC-C were well correlated during the placebo/baseline phase of the current study, they were not well correlated at completion of the 6-month maintenance phase of the medication trial. CONCLUSION: The DASH-II, while appropriate for assisting in the diagnosis of psychopathology in people with ID, does not appear to monitor changes in problem behaviour as a result of risperidone use as well as the ABC-C. Differences in the frequency of problem behaviour that each measure evaluated and the applicability of using the DASH-II to measure medication effects on problem behaviour are discussed.

Antipsychotic Agents↗
PubMed2001

Self-injurious behavior: gene-brain-behavior relationships.

This paper summarizes a conference held at the National Institute of Child Health and Human Development on December 6-7, 1999, on self-injurious behavior [SIB] in developmental disabilities. Twenty-six of the top researchers in the U.S. from this field representing 13 different disciplines discussed environmental mechanisms, epidemiology, behavioral and pharmacological intervention strategies, neurochemical substrates, genetic syndromes in which SIB is a prominent behavioral phenotype, neurobiological and neurodevelopmental factors affecting SIB in humans as well as a variety of animal models of SIB. Findings over the last decade, especially new discoveries since 1995, were emphasized. SIB is a rapidly growing area of scientific interest to both basic and applied researchers. In many respects it is a model for the study of gene-brain-behavior relationships in developmental disabilities.

Animals↗
PubMed2001

Brief report: effects of clozapine on self-injurious behavior of two risperidone nonresponders with mental retardation.

Atypical antipsychotic medications for self-injurious behavior (SIB), aggression, and destruction among people with mental retardation and development disabilities are becoming increasingly accepted. Most studies are on risperidone and fewer have been conducted on clozapine. The present single-blind study reports marked reductions in SIB and aggression of two persons with profound mental retardation who were nonresponsive to all other behavioral and psychopharmacological interventions, including risperidone. The most effective dose was 200 mg/day. Side effects were mild and the drug was tolerated well.

Adult↗
PubMed2001

Weight gain in a controlled study of risperidone in children, adolescents and adults with mental retardation and autism.

As part of an ongoing, prospective, ABA design, double-blind crossover study of risperidone versus placebo for the treatment of aggressive, destructive and self-injurious behavior in persons aged 6-65 years with mental retardation (MR) and autism, we measured the weight of 19 subjects at each study visit. We compared mean weight gain during the 16-week acute phase and 24-week open maintenance phase with that during the initial and middle placebo phases statistically, using a linear mixed model procedure. Results of the linear mixed model analysis showed that relative weight gain observed during the acute and maintenance drug phases was significantly greater than that observed during the initial and middle placebo phases respectively (p = .0001 and p = .0001). Over approximately a year, children aged 8-12 (n = 5) gained a mean of 8.2 kg (range = 2.7-17.7 kg); adolescents (n = 6) aged 13-16 gained a mean of 8.4 kg (range 3.6-15.5 kg); adults aged 21-51 (n = 8) gained a mean of 5.4 kg (range 0-9.5 kg). Weight gain observed in this controlled study of risperidone treatment in children, adolescents, and adults with MR and autism was significant. It may be greater in this population than in others reported and in this study was not limited to an acute effect only. Rate of weight gain diminished rapidly on tapering and stopping the drug. Further studies are urgently needed, including those incorporating diet and exercise programming.

Adolescent↗
PubMed2001

Effects of risperidone on aberrant behavior of persons with developmental disabilities: I. A double-blind crossover study using multiple measures.

The efficacy of the atypical antipsychotic risperidone was evaluated in the treatment of aberrant behavior (e.g., aggression, self-injury) in 20 individuals with developmental disabilities. A double-blind, crossover design was used to compare risperidone with placebo in a 22-week trial with a 6-month follow-up phase. Based on a 50% reduction in mean Aberrant Behavior Checklist--Community total scores, 50% of the participants were identified as responders. Naturalistic observations of a subset of five individuals showed that for 4 out of 5 participants, risperidone was effective in reducing aberrant behavior. Side effects included weight gain (84% of participants) and sedation (40% of participants). The advantages of conducting a comprehensive analysis of the effects of medication on aberrant behavior are discussed.

Adolescent↗
PubMed2000

Mental retardation and developmental disabilities influenced by environmental neurotoxic insults.

This paper sets a framework for the discussion of neurotoxicity as a potentially major contributor to the etiology of many types of mental retardation and developmental disabilities. In the past the literatures on developmental neurotoxicology and on mental retardation have evolved independently, yet we know that the developing brain is a target for neurotoxicity in the developing central nervous system through many stages of pregnancy as well as during infancy and early childhood. Our definitions and theories of mental retardation and developmental disabilities affect the models of neurotoxicity we espouse. For instance, models of developmental risk in neurotoxicology have guided environmental regulation to reduce the likelihood of neurotoxic effects. On the other hand, models of developmental risk for mental retardation aim not only at primary prevention,but also at secondary and tertiary prevention through early intervention. In the future, dynamic models of neuroplasticity based on the study of gene-brain-behavior relationships are likely to guide our views of developmental neurotoxicology and prevention of mental retardation and other disabilities.

Developmental Disabilities↗
PubMed1998

Cross-sensitization between footshock stress and apomorphine on self-injurious behavior and neostriatal catecholamines in a rat model of Lesch-Nyhan syndrome.

The effects of footshock sensitization (priming), apomorphine (APO) priming and their combination on behavior and neostriatal and cortical catecholamines were examined in adult rats which had neonatally received bilateral intracerebroventricular injections with 6-hydroxydopamine (6-OHDA; a model of Lesch-Nyhan syndrome (LNS)) or vehicle (unlesioned rats). Lesioned (6-OHDA-treated) rats displayed self-biting (SB; 7/20 rats) and self-injurious behavior (SIB; 1/20 rats) during APO priming, but not during footshock priming. During subsequent acute cumulative APO dosing, 20-30% of lesioned rats primed with APO alone or footshock alone displayed SB and SIB. However, SB and SIB incidence in APO+footshock-primed lesioned rats was nearly tripled. Dopamine (DA) synthesis, metabolism and extracellular concentrations (disposition) in unlesioned rats and in cortices of lesioned animals were unaffected by priming. In lesioned rats primed with APO alone or footshock alone, only neostriatal 3-methoxytyramine (3-MT) was significantly increased. However, neostriatal DA and metabolite concentrations (and norepinephrine (NE)) were all significantly elevated in lesioned rats primed with both APO and footshock. These results confirm that neonatal 6-OHDA-induced neostriatal catecholamine depletion can be antagonized by experiential change, suggest that behavioral and neurochemical cross-sensitization between APO and footshock in such rats is unidirectional and support the view that stress can exacerbate the incidence of SIB in LNS.

Animals↗
PubMed1998

Fixed-ratio discrimination training as replacement therapy in Parkinson's disease: studies in a 6-hydroxydopamine-treated rat model.

Severe 6-hydroxydopamine (6-OHDA)-induced neostriatal dopamine (DA) depletion is generally held to be irreversible. Adult rats administered 6-OHDA soon after weaning, or neonatally, respectively model Parkinson's disease (PD) and Lesch-Nyhan syndrome (LNS). Prior studies in our laboratory indicate that prolonged training on incrementally more difficult fixed-ratio (FR) discriminations can reverse 'irreversible' 6-OHDA-induced neostriatal DA depletion in adult LNS rats. The present study evaluated the effects of such training on neostriatal DA depletion and its functional consequences in adult PD and control (vehicle-injected) rats. After recovery from 6-OHDA-induced hypophagia, rats were sacrificed to assess neostriatal DA depletion magnitude, or were food-deprived and either subjected to food-maintained operant FR discrimination training or allowed to remain in their home cages. 6-OHDA treatment antagonized amphetamine (AMP)-induced increases in brief rearing behavior and locomotor activity in 3-month-old PD rats prior to training, and reduced operant response rates throughout training without affecting learning rates. One week after training, AMP-increased locomotor and brief-rearing frequencies were augmented in all groups except trained controls, and the prior inhibitory effect of 6-OHDA treatment on AMP-increased behavioral frequencies was essentially eliminated. Cumulative apomorphine (APO) dose-effect curve (0.1-3.2 mg/kg) construction 3 weeks post-training revealed that 6-OHDA treatment abolished APO-induced intense licking behavior. However, training eliminated the hyperresponsiveness of 6-OHDA-treated rats to the locomotor- and brief-rearing stimulant effects of APO but did not affect the depletion of neostriatal DA. Nevertheless, 6-OHDA-induced increases in neostriatal DOPAC/DA and HVA/DA ratios were normalized by age/food-deprivation while that of 3MT/DA was not. These findings suggest that training reduces the functional responsiveness of at least some central DA receptors, FR discrimination training could be a useful adjunct to PD replacement therapy and that the neostriatal DA-repleting action of training in 6-OHDA-treated rats depend on the age at which 6-OHDA is administered.

Amphetamine↗
PubMed1997

Effects of neuroleptic and anticonvulsant drugs on repeated acquisition learning in microencephalic and normal rats.

Neuroleptic and anticonvulsant drugs are used to reduce the occurrence of aberrant behaviors, seizures, or both in individuals with mental retardation. However, their use may disrupt the learning of desired skills, and the extent to which anatomical (e.g., microencephaly) or biochemical abnormalities or both in such individuals alter the effects of drugs on learning is not known. In this study, the effects of neuroleptics and anticonvulsants on learning and performance in a repeated acquisition task in methylazoxymethanol-induced microencephalic and saline control rats were assessed. Thioridazine was more potent in microencephalic rats than in control rats in increasing errors and decreasing response rates. Clozapine was equally potent in both microencephalic and control rats in increasing errors and decreasing response rates. The effect of carbamazepine was biphasic in both rat groups: Low doses decreased errors and increased response rates, whereas higher doses did the opposite.

Animals↗
PubMed1996

FR discrimination training reverses 6-hydroxydopamine-induced striatal dopamine depletion in a rat model of Lesch-Nyhan syndrome.

Five-day-old rats received 6-hydroxydopamine (6-HD; 100 micrograms base) or vehicle intracisternally. Striatal and cortical dopamine (DA) and metabolite levels were then determined when animals were three or 8.5 months of age and the latter rats had been weight-reduced for 5.5 months. In the latter animals these determinations were made 1 month following 4.5 months of home-cage confinement (untrained animals) or of food-maintained fixed-ratio (FR) discrimination training involving either a single discrimination (performance animals) or incrementally more difficult discriminations. Striatal DA levels in 3-month-old and 8.5-month-old (untrained) 6-HD-treated rats were, respectively, only 3% and 11% of those in untrained vehicle-treated animals (controls). Despite such large depletions, striatal DA levels in 6-HD-treated performance rats were 3-fold higher than those in untrained age-matched 6-HD-treated rats (i.e., were 32% of values in controls) while those in incrementally trained 6-HD-treated animals were even higher (i.e., were 60% of control values). Related changes occurred in levels of most metabolites. However, in incrementally trained rats, striatal 3-methoxytyramine concentrations were 154% of control values. Cortical DA and metabolite levels were little affected by 6-HD treatment. The present results confirm and extend our earlier observations suggesting that reversal of 'irreversible' neonatal 6-HD-induced striatal dopamine and metabolic depletion can be accomplished by environmental (training) manipulations in adult rats.

Animals↗
PubMed1995

The effect of clozapine on self-injurious behavior.

Traditional neuroleptic drugs like thioridazine and haloperidol have not proven to be systematically effective with the treatment of self-injurious behavior (SIB). These drugs may be ineffective because they primarily block D2 dopamine receptors. Based on research with humans and other animals, it appears that another dopamine receptor, D1, may be responsible for mediating some SIB. Clozapine, a neuroleptic recently introduced in the United States, has proven effective in treatment of refractory cases of schizophrenia and is known to have an affinity for blocking D1 receptors. The drug was used to complete a 93-week double-blind crossover trial with a client displaying chronic SIB. Though clozapine is known to affect other neurotransmitter systems, the successful treatment of the participant is consistent with the D1 hypothesis of self-injurious behavior and suggests the possibility that clozapine could be an effective pharmacological intervention for some cases of SIB.

Adult↗
PubMed1995

FR discrimination training effects in SHR and microencephalic rats.

Fixed-ratio (FR) discrimination learning in adult male spontaneously hypertensive rats (SHR), methylazoxymethanol-induced microencephalic Sprague-Dawley (MAM), and Sprague-Dawley control rats was examined. SHR and MAM rats had little problem learning incrementally more difficult FR discriminations (FR1 vs. FR16, FR4 vs. FR16, and FR8 vs. FR16) that resulted in parallel increases in errors in all animals, and displayed only modest learning deficits during a subsequent FR4 vs. FR16 position reversal. When training involved nonincremental changes in difficulty (FR8 vs. FR16, FR4 vs. FR16, FR8 vs. FR16, FR12 vs. FR16, and FR14 vs. FR16), SHR and MAM rats evidenced relatively large learning deficits during the initial FR8 vs. FR16 discrimination but had no difficulty with the last two discriminations. Furthermore, training selectively and significantly elevated hippocampal weight in MAM rats. These findings: a) question prior suggestions that MAM and SHR model separate human developmental disabilities; b) indicate that manifestation of learning deficits in even markedly brain-damaged organisms depends on initial task difficulty and can be overcome by experience; and c) are the first indicating that training-induced antagonism of prenatally induced hippocampal hypoplasia and its consequences is possible.

Animals↗
PubMed1995

Reversal of 6HD-induced neonatal brain catecholamine depletion after operant training.

Rats received either vehicle (controls) or 100 micrograms of 6-hydroxydopamine (6HD) base intracisternally on postnatal day 5. At 3 mo of age, striatal and cortical catecholamine and metabolite levels were determined in some animals. Others were subjected to 4.5 mo of training on incrementally more difficult fixed-ratio (FR) discriminations; 2 mo later, their levels were determined. Learning was essentially unaffected by 6HD even though errors in all animals increased with increases in discrimination difficulty and 6HD had markedly depleted levels in the 3-mo-old animals. Moreover, an initial response-rate deficit in 6HD-treated rats disappeared with training. However, after training, levels in 6HD-treated rats were not only not depleted, they were as much as 661% of those in controls. These and others of our findings indicate that FR discrimination training can induce persistent increases in brain catecholamine utilization. They also appear to be the first to suggest that at least some neurochemical effects of neonatal 6HD are not necessarily irreversible, and that such a reversal can be experientially induced and possibly functionally beneficial.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1993

Biological and environmental risk for poor developmental outcome of young children.

A cross-sectional retrospective study was conducted to develop and field test a state-wide screening method for identifying children at risk for developmental problems. Families of 2.5- to 3-year-old children were sampled from the Ohio birth certificate register. Standardized telephone interviews were conducted with 1,601 parents concerning home environment and demographic characteristics. Developmental delay, the outcome variable, was defined by low scores on an abbreviated Developmental Profile II, which was also administered over the telephone. Obstetric history and health status of the newborns was obtained from birth certificates. By means of logistic regression analysis, we found six independent variables representing environmental and biological determinants.

Child Development↗
PubMed1992

Risk factors for developmental delay among infants and toddlers.

Definitions of risk, types of risk factors used in longitudinal studies of the development of infants and toddlers (0-3 years), and the predictive power of risk models in assessing developmental delays are reviewed. Biologic factors in combination with environmental risk factors give the best prediction of long-term outcome. When biological or environmental risk factors are examined independently, they are not powerful predictors. Recommendations are made for repeated screening for developmental risk factors during the first 3 years, and a model for provision of services is presented that assumes a differential risk algorithm.

Child, Preschool↗
PubMed1991

Predictors of urgency of out-of-home placement needs.

A random sample of 137 families from an out-of-home placement waiting list were surveyed through structured face-to-face interviews with the primary caregivers. Our purposes were to identify predictors of urgency of a family's placement need and obtain information about needed support services, which might help to maintain the person at home. A hierarchical regression analysis was calculated with caregiver stressors and behavior problems as independent variables and the urgency of out-of-home placement need as the dependent variable. Only caregiver stress variables emerged as a significant predictor.

Adolescent↗