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Biomedical subjects

James T McCracken

Publications and source records attributed to James T McCracken.

At least 19 recordsLinked to original sources
PubMed2007

The association of DRD4 and novelty seeking is found in a nonhuman primate model.

OBJECTIVE: The association of novelty seeking with a repeat polymorphism in the coding region of the dopamine D4 receptor gene (DRD4) has been demonstrated in several human populations, but not in others. The objective of this study was to test the generality of the association in a captive nonhuman primate population of known history, using objective methods for assessing novelty seeking and a pedigree-based association design. METHODS: Four hundred and fifty two socially-living vervet monkeys (Cercopithecus aethiops) from a large multigenerational pedigree at the UCLA-VA Vervet Research Colony were studied. Two variants in the 48 base pair repeat in exon III of the DRD4 gene have been found in this population, a six-repeat (92%) and a less common five-repeat (8%). Novelty seeking was measured by the latency to approach a large and potentially threatening novel object placed in the home enclosure. Heritability of novelty seeking and the association of novelty seeking with the DRD4 polymorphism were assessed using variance component modeling as implemented in Sequential Oligogenic Linkage Analysis Routines. RESULTS: The variance component analysis indicated that the DRD4 variant explained a significant portion of the total variance in novelty seeking. The final model included a significant effect of the DRD4 polymorphism (P=0.03), which explained 13% of the phenotypic variance, and a significant remaining genetic effect (h=0. 467+/-0.095, P<0.0001). CONCLUSIONS: The association of DRD4 with novelty seeking has now been replicated in a nonhuman primate species, the vervet monkey.

Analysis of Variance↗
PubMed2006

Direct health care costs for children with pervasive developmental disorders: 1996-2002.

We compared direct costs of treatment of Pervasive Developmental Disorder (PDD), asthma, and diabetes in children aged 3-17 years. A retrospective, claims-based study was conducted using the California Medicaid (Medi-Cal) database (1996-2002). Seven hundred and thirty-one children with PDD were identified and matched for sex with an equal number of randomly selected children with asthma and diabetes. Mean total health care costs for PDD were two- to threefold higher than for asthma and diabetes post-diagnosis ($4,815 vs. $1,469 vs. $2,404, respectively, P < 0.0001). Children with PDD incur significantly greater health care costs when compared with children with other chronic pediatric diseases.

Adolescent↗
PubMed2006

Familiality of factor analysis-derived YBOCS dimensions in OCD-affected sibling pairs from the OCD Collaborative Genetics Study.

BACKGROUND: Identification of familial, more homogenous characteristics of obsessive-compulsive disorder (OCD) may help to define relevant subtypes and increase the power of genetic and neurobiological studies of OCD. While factor-analytic studies have found consistent, clinically meaningful OCD symptom dimensions, there have been only limited attempts to evaluate the familiality and potential genetic basis of such dimensions. METHODS: Four hundred eighteen sibling pairs with OCD were evaluated using the Structured Clinical Interview for DSM-IV and the Yale-Brown Obsessive Compulsive Scale (YBOCS) Symptom Checklist and Severity scales. RESULTS: After controlling for sex, age, and age of onset, robust sib-sib intraclass correlations were found for two of the four YBOCS factors: Factor IV (hoarding obsessions and compulsions (p = .001) and Factor I (aggressive, sexual, and religious obsessions, and checking compulsions; p = .002). Smaller, but still significant, familiality was found for Factor III (contamination/cleaning; p = .02) and Factor II (symmetry/ordering/arranging; p = .04). Limiting the sample to female subjects more than doubled the familiality estimates for Factor II (p = .003). Among potentially relevant comorbid conditions for genetic studies, bipolar I/II and major depressive disorder were strongly associated with Factor I (p < .001), whereas ADHD, alcohol dependence, and bulimia were associated with Factor II (p < .01). CONCLUSIONS: Factor-analyzed OCD symptom dimensions in sibling pairs with OCD are familial with some gender-dependence, exhibit relatively specific relationships to comorbid psychiatric disorders and thus may be useful as refined phenotypes for molecular genetic studies of OCD.

Comorbidity↗
PubMed2006

Hoarding in obsessive-compulsive disorder: results from the OCD Collaborative Genetics Study.

Hoarding behavior occurs frequently in obsessive-compulsive disorder (OCD). Results from previous studies suggest that individuals with OCD who have hoarding symptoms are clinically different than non-hoarders and may represent a distinct clinical group. In the present study, we compared 235 hoarding to 389 non-hoarding participants, all of whom had OCD, collected in the course of the OCD Collaborative Genetics Study. We found that, compared to non-hoarding individuals, hoarders were more likely to have symmetry obsessions and repeating, counting, and ordering compulsions; poorer insight; more severe illness; difficulty initiating or completing tasks; and indecision. Hoarders had a greater prevalence of social phobia and generalized anxiety disorder. Hoarders also had a greater prevalence of obsessive-compulsive and dependent personality disorders. Five personality traits were independently associated with hoarding: miserliness, preoccupation with details, difficulty making decisions, odd behavior or appearance, and magical thinking. Hoarding and indecision were more prevalent in the relatives of hoarding than of non-hoarding probands. Hoarding in relatives was associated with indecision in probands, independently of proband hoarding status. The findings suggest that hoarding behavior may help differentiate a distinct clinical subgroup of people with OCD and may aggregate in some OCD families. Indecision may be a risk factor for hoarding in these families.

Adolescent↗
PubMed2006

Effects of short- and long-term risperidone treatment on prolactin levels in children with autism.

BACKGROUND: The effects of short- and long-term risperidone treatment on serum prolactin were assessed in children and adolescents with autism. METHODS: Patients with autism (N = 101, 5-17 years of age) were randomized to an 8-week trial of risperidone or placebo and 63 then took part in a 4-month open-label follow-up phase. Serum samples were obtained at Baseline and Week-8 (N = 78), and at 6-month (N = 43) and 22-month (N = 30) follow-up. Serum prolactin was determined by immunoradiometric assay; dopamine type-2 receptor (DRD2) polymorphisms were genotyped. RESULTS: Baseline prolactin levels were similar in the risperidone (N = 42) and placebo (N = 36) groups (9.3 +/- 7.5 and 9.3 +/- 7.6 ng/ml, respectively). After 8 weeks of risperidone, prolactin increased to 39.0 +/- 19.2 ng/ml, compared with 10.1 +/- 8.8 ng/ml for placebo (p < .0001). Prolactin levels were also significantly increased at 6 months (32.4 +/- 17.8 ng/ml; N = 43, p < .0001) and at 22 months (N = 30, 25.3 +/- 15.6 ng/ml, p < .0001). Prolactin levels were not associated with adverse effects and DRD2 alleles (Taq1A, -141C Ins/Del, C957T) did not significantly influence baseline levels or risperidone-induced increases in prolactin. CONCLUSIONS: Risperidone treatment was associated with two- to four-fold mean increases in serum prolactin in children with autism. Although risperidone-induced increases tended to diminish with time, further research on the consequences of long-term prolactin elevations in children and adolescents is needed.

Adolescent↗
PubMed2006

The OCD collaborative genetics study: methods and sample description.

Results from twin and family studies suggest that obsessive-compulsive disorder (OCD) may be transmitted in families but, to date, genes for the disorder have not been identified. The OCD Collaborative Genetics Study (OCGS) is a six-site collaborative genetic linkage study of OCD. Specimens and blinded clinical data will be made available through the National Institute of Mental Health (NIMH) cell repository. In this initial report, we describe the methods of the study and present clinical characteristics of affected individuals for researchers interested in this valuable resource for genetic studies of OCD. The project clinically evaluated and collected blood specimens from 238 families containing 299 OCD-affected sibling pairs and their parents, and additional affected relative pairs, for a genome-wide linkage study. Of the 999 individuals interviewed to date, 624 were diagnosed with "definite" OCD. The mean age of subjects was 36 years (range 7-95). The majority of affected individuals (66%) were female. The mean age at onset of obsessive-compulsive symptoms was 9.5 years. Specific mood disorders, anxiety disorders, eating disorders, and skin picking were more prevalent in female cases, whereas tics, Tourette disorder, and alcohol dependence were more prevalent in male cases. Compared to "definite" cases of OCD, "probable" cases (n = 82) had, on average, later age at onset of obsessive-compulsive symptoms, lower severity score, and fewer numbers of different categories of obsessions and compulsions, and they were less likely to have received treatment for their symptoms.

Adolescent↗
PubMed2006

Gene variants of brain dopamine pathways and smoking-induced dopamine release in the ventral caudate/nucleus accumbens.

CONTEXT: Preclinical studies demonstrate that nicotine administration leads to dopamine release in the ventral striatum. However, human studies reveal considerable interindividual variability in the extent of smoking-induced dopamine release. OBJECTIVE: To determine whether common gene variants of the brain dopamine pathway explain this observed phenotypic variability in humans. DESIGN: Blood samples were drawn to determine gene variants of dopamine system components, and positron emission tomography scanning with the radiotracer raclopride labeled with radioactive carbon (11C) was performed to measure smoking-induced dopamine release. SETTING: Academic brain imaging center. PARTICIPANTS: Forty-five tobacco-dependent smokers. INTERVENTIONS: Subjects either smoked a cigarette (n = 35) or did not smoke (n = 10) during positron emission tomography scanning. MAIN OUTCOME MEASURES: Gene variants of dopamine system components (the dopamine transporter variable nucleotide tandem repeat, D2 receptor Taq A1/A2, D4 receptor variable nucleotide tandem repeat, and catechol-O-methyltransferase Val158Met polymorphisms) and change in [11C]raclopride binding potential in the ventral caudate/nucleus accumbens on positron emission tomography scans. RESULTS: For subjects who smoked during scanning, those with at least one 9 allele of the dopamine transporter variable nucleotide tandem repeat, fewer than 7 repeats of the D4 variable nucleotide tandem repeat, and the Val/Val catechol-O-methyltransferase genotype had greater decreases in binding potential (an indirect measure of dopamine release) with smoking than those with the alternate genotypes. An overall decrease in ventral caudate/nucleus accumbens binding potential in those who smoked compared with those who did not smoke was also found but was smaller in magnitude than previously reported. CONCLUSIONS: Smokers with genes associated with low resting dopamine tone have greater smoking-induced (phasic) dopamine release than those with alternate genotypes. These findings suggest that dopamine system genotype variabilities explain a significant proportion of the interindividual variability in smoking-induced dopamine release and indicate that smoking-induced dopamine release has a genetic predisposition.

Adult↗
PubMed2006

Dietary status and impact of risperidone on nutritional balance in children with autism: a pilot study.

BACKGROUND: Risperidone may be effective in improving tantrums, aggression, or self-injurious behaviour in children with autism, but often leads to weight gain. METHOD: Using a quantitative Food Frequency Questionnaire (FFQ), we prospectively examined the nutritional intake of 20 children with autism participating in a randomised placebo-controlled trial of risperidone for disruptive behaviours. RESULTS: At baseline, the mean intakes for macronutrients, vitamins and minerals exceeded Dietary Reference Intakes (DRIs). However there was substantial inter-participant variability, with individual deficiencies (<80% of DRI) in the intake of calcium (9 of 20 participants), pantothenic acid (6 of 20), vitamin D (5 of 20) and vitamin K (8 of 20). For the participants for whom FFQs were available, there was an increase in weight and an increase in vitamin K intake after 2 months of risperidone treatment (n = 9) compared to placebo (n = 8). An additional 4 months of risperidone treatment (n = 8) did not result in significant changes in reported nutritional balance. CONCLUSION: These pilot data suggest that treatment with risperidone did not significantly affect the nutritional balance of this small group of children.

Adolescent↗
PubMed2006

A prospective open trial of guanfacine in children with pervasive developmental disorders.

OBJECTIVE: A common complaint for children with pervasive developmental disorder (PDD) is hyperactivity. The purpose of this pilot study was to gather preliminary information on the efficacy of guanfacine in children with PDD and hyperactivity. METHODS: Children with PDD accompanied by hyperactivity entered the open-label trial if there was a recent history of failed treatment with methylphenidate or the child did not improve on methylphenidate in a multisite, placebo-controlled trial. RESULTS: Children (23 boys and 2 girls) with a mean age of 9.03 (+/-3.14) years entered the open-label trial. After 8 weeks of treatment, the parent-rated Hyperactivity subscale of the Aberrant Behavior Checklist (ABC) went from a mean of 31.3 (+/-8.89) at baseline to 18.9 (+/-10.37) (effect size = 1.4; p < 0.001). The teacher-rated Hyperactivity subscale decreased from a mean of 29.9 (+/-9.12) at baseline to 22.3 (+/-9.44) (effect size = 0.83; p < 0.01). Twelve children (48%) were rated as Much Improved or Very Much Improved on the Clinical Global Impressions- Improvement. Doses ranged from 1.0 to 3.0 mg/day in two or three divided doses. Common adverse effects included irritability, sedation, sleep disturbance (insomnia or midsleep awakening), and constipation. Irritability led to discontinuation in 3 subjects. There were no significant changes in pulse, blood pressure, or electrocardiogram. CONCLUSIONS: Guanfacine may be useful for the treatment of hyperactivity in children with PDD. Placebo-controlled studies are needed to guide clinical practice.

Adolescent↗
PubMed2006

Risperidone and adaptive behavior in children with autism.

OBJECTIVE: To evaluate the impact of risperidone on adaptive behavior in children with autistic disorder who have serious behavior problems and to examine different methods of scoring the Vineland Adaptive Behavior Scales to measure change. METHOD: Forty-eight children (5 years to 16 years, 5 months) who showed behavioral improvement during acute treatment with risperidone were followed for 6 months and assessed with the Vineland Scales. RESULTS: Raw scores, age-equivalents, and special norm percentile scores all showed significant increases in adaptive behavior in the areas of communication, daily living skills, and socialization (p <.01). During a period of 6 to 8 months, children gained an average of 7.8 age-equivalent months in the area of socialization, a > 6% improvement beyond what would be expected based on baseline growth rates. CONCLUSIONS: Although limited by the absence of a control group, these results suggest that risperidone may improve adaptive skills in children with autistic disorder accompanied by serious behavioral problems. Vineland age-equivalent scores appear to be most useful in assessing change with treatment over time.

Activities of Daily Living↗
PubMed2006

Children's Yale-Brown Obsessive Compulsive Scale modified for pervasive developmental disorders.

OBJECTIVE: To examine the psychometric properties of the Children's Yale-Brown Obsessive Compulsive Scales (CYBOCS) modified for pervasive developmental disorders (PDDs). METHOD: Raters from five Research Units on Pediatric Psychopharmacology (RUPP) Autism Network were trained to reliability. The modified scale (CYBOCS-PDD), which contains only the five Compulsion severity items (range 0-20), was administered to 172 medication-free children (mean 8.2 +/- 2.6 years) with PDD (autistic disorder, n = 152; Asperger's disorder, n = 6; PDD not otherwise specified, n = 14) participating in RUPP clinical trials. Reliability was assessed by intraclass correlation coefficient (ICC) and internal consistency by Cronbach's alpha coefficient. Correlations with ratings of repetitive behavior and disruptive behavior were examined for validity. RESULTS: Eleven raters showed excellent reliability (ICC = 0.97). The mean CYBOCS score was 14.4 (+/- 3.86) with excellent internal consistency (alpha = .85). Correlations with other measures of repetitive behavior ranged from r = 0.11 to r = 0.28 and were similar to correlations with measures of irritability (r = 0.24) and hyperactivity (r = 0.25). Children with higher scores on the CYBOCS-PDD had higher levels of maladaptive behaviors and lower adaptive functioning. CONCLUSIONS: The five-item CYBOCS-PDD is reliable, distinct from other measures of repetitive behavior, and sensitive to change.

Antipsychotic Agents↗
PubMed2006

Validity of the autism diagnostic interview-revised.

The factor structure, internal consistency, and convergent validity of the Autism Diagnostic Interview-Revised (ADI-R) algorithm items were examined in a sample of 226 youngsters with pervasive developmental disabilities. Exploratory factor analyses indicated a three-factor solution closely resembling the original algorithm and explaining 38% of the variance, with one significant discrepancy: Unlike the algorithm, all nonverbal communication items were associated with the Social factor. Internal consistencies of domain scores ranged from .54 to .84. Correlations between ADI-R domain and total scores and instruments assessing adaptive behavior, psychopathology, and autism were examined. They indicated some similarities between constructs, but also that the ADI-R measures autism in a unique fashion.

Adolescent↗
PubMed2005

Atypical brain laterality in adults with ADHD during dichotic listening for emotional intonation and words.

Few studies directly examined the nature of hemispheric specialization and interaction in ADHD. The present experiment investigated left/right brain dynamics in unmedicated right handed adults with ADHD (n = 19) and in controls (n = 19), using a dichotic listening task to assess hemispheric differences in word and emotion recognition. We also assessed how focusing attention on a single ear modulated lateralized performance and affected cross-callosal interference effects. Analysis of variance indicated that ADHD subjects showed reduced left hemisphere specialization, were better at processing emotions, and worse at processing words compared to controls. These differences were eliminated during focused attention. Finally, during presumed right hemisphere processing of linguistic stimuli, subjects with ADHD showed reduced left hemisphere interference. We concluded that ADHD subjects demonstrated greater right hemisphere and reduced left hemisphere contribution during this task relative to controls. We posit that these hemispheric differences were due to management or use of available cognitive resources rather than inherent capacity.

Acoustic Stimulation↗
PubMed2005

Abnormal development of the anterior cingulate in childhood-onset schizophrenia: a preliminary quantitative MRI study.

The anterior cingulate is a key component of neural networks subserving attention and emotion regulation, functions often impaired in patients with psychosis. The study aimed to examine anterior cingulate volumes and sulcal morphology in a group of patients with childhood-onset schizophrenia (COS) compared with controls. Brain magnetic resonance imaging (MRI) scans were obtained in 13 COS and 18 matched control children, ages 6-17 years. Volume measures for the anterior cingulate gyrus (ACG) were obtained through manual labeling. A determination of cingulate sulcal pattern (single or double) was made for each hemisphere. The COS group had a reduced leftward skew of the double cingulate sulcal pattern, and absence of the normal left>right ACG volume asymmetry. The right ACG was larger in the COS than in controls. The schizophrenic children showed decreases in all ACG volumes with age, while the controls showed increases or no change. The data suggest that significant cingulate abnormalities may result from deviations in progressive neurodevelopmental processes, beginning before birth and continuing through childhood and adolescence, in persons who develop schizophrenia. These structural differences may relate to the well-described cognitive deficits these children display, and to the cardinal symptoms of schizophrenia.

Adolescent↗
PubMed2005

Elevated thyroid indices in children and adolescents with obsessive-compulsive disorder: effects of clomipramine treatment.

OBJECTIVE: To examine the basal thyroid function in pediatric Obsessive Compulsive Disorder (OCD) versus controls, and to explore the relation between baseline thyroid measures and response to clomipramine treatment, and the effects of treatment on thyroid hormones. METHODS: Sixteen children and adolescents with DSM-III-R OCE and 13 control children and adolescents without psychiatric illness were compared on basal measures of thyroid-stimulating hormone (TSH), triiodothyronine (T3), and thyroxine (T4). For the OCD subjects, samples were compared pre- and post- 4 weeks of treatment with clomipramine. Response of OCD symptoms was measured by the Children's Yale-Brown Obsessive Compulsive Scale (CY-BOCS). RESULTS: OCD subjects demonstrated subtle but significant elevations of TSH, T3, and T4 pre-treatment compared to controls. Clomipramine treatment was associated with significant decreases in TSH and T3 concentrations. Pre-treatment TSH and T4 concentrations correlated with reductions in CY-BOCS following 8 weeks of clomipramine. CONCLUSION: Elevated thyroid function at baseline may be a biomarker of OCD improvement, and may reflect aspects of the underlying pathophysiology of OCD.

Adolescent↗
PubMed2005

Acute and long-term safety and tolerability of risperidone in children with autism.

Treatment-emergent adverse events (AEs) were monitored during an 8-week, double-blind, placebo-controlled trial of risperidone (0.5-3.5 mg/day) in 101 children and adolescents with a lifetime diagnosis of autistic disorder. In addition, 37 placebo nonresponders received open-label risperidone for another 8 weeks. Of all the risperidone responders (n=65), 63 entered an open extension of another 16 weeks (6 months total risperidone exposure), and 32 of them were rerandomized to either continued risperidone therapy (n=16) or gradual replacement with placebo (n=16) over 8 weeks. We collected the following measures of safety and tolerability: (1) laboratory blood assessments (CBC with differential, electrolytes, and liver function tests) and urinalyses, (2) vital signs, (3) Side Effects Review of AEs thought to be associated with risperidone, (4) sleep records, (5) Simpson Angus Neurological Rating Scale (SARS), (6) Abnormal Involuntary Movement Scale (AIMS), and (7) height and weight. No clinically significant changes were found on the lab tests. During the 8-week acute trial, the most common AEs on the Side Effects Review, scored as moderate or higher, were as follows (placebo and risperidone, respectively): Somnolence (12% and 37%), enuresis (29% and 33%), excessive appetite (10% and 33%), rhinitis (8% and 16%), difficulty waking (8% and 12%), and constipation (12% and 10%). "Difficulty falling asleep" and anxiety actually favored the risperidone condition at statistically significant levels. The same AEs tended to recur through 6 months of treatment, although often at reduced levels. Using Centers for Disease Control (CDC) standardized scores, both weight and body mass index (BMI) increased with risperidone during the acute trial (0.5 and 0.6 SDs, respectively, for risperidone; 0.0 and 0.1 SDs, respectively, for placebo) and into open-label extension (0.19 and 0.16 SDs, respectively), although the amount of gain decelerated with time. Extrapyramidal symptoms, as assessed by the SARS, were no more common for drug than placebo, although drooling was reported more often in the risperidone group. There were no differences between groups on the AIMS. Two subjects had seizures (one taking placebo), but these were considered unrelated to active drug. Most AEs were mild to moderate and failed to interfere with therapeutic changes; there were no unanticipated AEs. The side effects of most concern were somnolence and weight gain.

Adolescent↗
PubMed2005

Research knowledge among parents of children participating in a randomized clinical trial.

OBJECTIVE: Parental permission is required for child research, but parents' understanding of research aims and procedures has not been well documented. Parental research knowledge was assessed during a clinical trial in autism. METHOD: Parents of 101 children (age 5-17 years) with autism participating in a placebo-controlled trial of risperidone were given a questionnaire at the end of the study. RESULTS: Of the 95 parents completing the questionnaire, 99% knew of possible placebo assignment and that testing the medication efficacy was the main purpose of the investigators; 96% to 98% knew that research involved both risks and potential benefits, identified the study medication, and knew of their right to withdraw at any time; 90% to 95% knew of the medication's main side effects; 87% reported having been informed of possible alternatives to research participation; and 72% were aware that treatment was randomly assigned (whereas 27% reported that treatment was chosen based on individual needs to ensure best care). Parents with a college degree were more likely to recognize the random nature of treatment assignment. CONCLUSIONS: Overall, parents were highly knowledgeable of the main research components. About one fourth, however, seemed unaware that treatment was randomly determined and not personalized, suggesting that therapeutic misconception may affect some otherwise well-informed parents.

Adolescent↗