Christopher J. McDougle

Autism genome-wide copy number variation reveals ubiquitin and neuronal genes

Autism spectrum disorders (ASDs) are childhood neurodevelopmental disorders with complex genetic origins. Previous studies focusing on candidate genes or genomic regions have identified several copy number variations (CNVs) that are associated with an increased risk of ASDs. Here we present the results from a whole-genome CNV study on a cohort of 859 ASD cases and 1,409 healthy children of European ancestry who were genotyped with ∼550,000 single nucleotide polymorphism markers, in an attempt to comprehensively identify CNVs conferring susceptibility to ASDs. Positive findings were evaluated in an independent cohort of 1,336 ASD cases and 1,110 controls of European ancestry. Besides previously reported ASD candidate genes, such as NRXN1 (ref. 10) and CNTN4 (refs 11, 12), several new susceptibility genes encoding neuronal cell-adhesion molecules, including NLGN1 and ASTN2, were enriched with CNVs in ASD cases compared to controls (P = 9.5 × 10-3). Furthermore, CNVs within or surrounding genes involved in the ubiquitin pathways, including UBE3A, PARK2, RFWD2 and FBXO40, were affected by CNVs not observed in controls (P = 3.3 × 10-3). We also identified duplications 55 kilobases upstream of complementary DNA AK123120 (P = 3.6 × 10-6). Although these variants may be individually rare, they target genes involved in neuronal cell-adhesion or ubiquitin degradation, indicating that these two important gene networks expressed within the central nervous system may contribute to the genetic susceptibility of ASD.

Synergistic action of 5-HT2A antagonists and selective serotonin reuptake inhibitors in neuropsychiatric disorders.

Recently, the addition of drugs with prominent 5-HT2 receptor antagonist properties (risperidone, olanzapine, mirtazapine, and mianserin) to selective serotonin reuptake inhibitors (SSRIs) has been shown to enhance therapeutic responses in patients with major depression and treatment-refractory obsessive–compulsive disorder (OCD). These 5-HT2 antagonists may also be effective in ameliorating some symptoms associated with autism and other pervasive developmental disorders (PDDs). At the doses used, these drugs would be expected to saturate 5-HT2A receptors. These findings suggest that the simultaneous blockade of 5-HT2A receptors and activation of an unknown constellation of other 5-HT receptors indirectly as a result of 5-HT uptake inhibition might have greater therapeutic efficacy than either action alone. Animal studies have suggested that activation of 5-HT1A and 5-HT2C receptors may counteract the effects of activating 5-HT2A receptors. Additional 5-HT receptors, such as the 5-HT1B/1D/5/7 receptors, may similarly counteract the effects of 5-HT2A receptor activation. These clinical and preclinical observations suggest that the combination of highly selective 5-HT2A antagonists and SSRIs, as well as strategies to combine high-potency 5-HT2A receptor and 5-HT transporter blockade in a single compound, offer the potential for therapeutic advances in a number of neuropsychiatric disorders.

Risperidone Treatment of Children and Adolescents With Pervasive Developmental Disorders: A Prospective, Open-Label Study

OBJECTIVE To investigate the short-term safety and efficacy of risperidone in the treatment of children and adolescents with pervasive developmental disorders. METHOD This was a 12-week, prospective, systematic, open-label trial that included 18 subjects (15 boys and 3 girls) with a mean age of 10.2 +/- 3.7 years. The sample included 11 subjects with autistic disorder, 3 with Aspergers disorder, 1 with childhood disintegrative disorder, and 3 with pervasive developmental disorder not otherwise specified. Fourteen subjects had comorbid mental retardation. Behavioral ratings were obtained during two baseline visits and again after 12 weeks of risperidone treatment. RESULTS The optimal dose of risperidone for the 18 subjects was 1.8 +/- 1.0 mg/day. On the basis of the global improvement item of the Clinical Global Impression Scale, 12 of 18 subjects were considered responders. Significant improvement was seen in measures of interfering repetitive behavior, aggression and impulsivity, and some elements of impaired social relatedness. The most common side effect was weight gain (range 10 to 35 lb). CONCLUSIONS These preliminary results suggest that risperidone may be effective for improving interfering behavioral symptoms in some children and adolescents with pervasive developmental disorders. Double-blind, placebo-controlled studies are needed before definitive statements of safety and efficacy can be made.

Evidence for linkage disequilibrium between serotonin transporter protein gene (SLC6A4) and obsessive compulsive disorder

Obsessive compulsive disorder (OCD) is characterized by recurrent and intrusive thoughts that are distressing (obsessions) and/or repetitive behaviors or mental acts that the person feels driven to perform (compulsions). OCD has a partly genetic basis. For treatment of OCD, potent serotonin reuptake inhibitor (SRI) drugs (clomipramine (Anafranil), fluvoxamine (Luvox), fluoxetine (Prozac), sertraline (Zoloft), and paroxetine (Paxil)), which act on the serotonin transporter protein, are uniquely efficacious. A polymorphism in the promoter region of the gene (SLC6A4) encoding this protein,1 was recently reported to affect protein expression and to be associated with measures of anxiety and depression2 and with autism (using a family-controlled transmission disequilibrium test (TDT) design).3 SLC6A4 therefore has strong a priori support for potentially influencing risk for OCD: the protein it encodes is a medication target; a polymorphism in the gene affects function; and that polymorphism has been shown to be associated with behavioral phenotypes. We used the TDT with a set of 34 European-American family trios, 30 unrelated and four drawn from an extended pedigree, to test for linkage disequilibrium between OCD and alleles at the SLC6A4 promoter polymorphic locus. Of 35 heterozygous parents, 24 transmitted the ‘l’ SLC6A4 allele and 11 transmitted the ‘s’ allele (χ2TDT = 4.83; P<0.03). considering only the 13 sri drug nonresponders, there were 13 heterozygous parents, of whom 10 transmitted the ‘l’ allele and three the ‘s’ allele (χ2TDT = 3.77; P<0.052). these data provide preliminary support for association and linkage disequilibrium between the slc6a4 ‘l’ allele and ocd.

Medication and Parent Training in Children With Pervasive Developmental Disorders and Serious Behavior Problems: Results From a Randomized Clinical Trial

OBJECTIVE Many children with pervasive developmental disorders (PDDs) have serious, functionally impairing behavioral problems. We tested whether combined treatment (COMB) with risperidone and parent training (PT) in behavior management is superior to medication alone (MED) in improving severe behavioral problems in children with PDDs. METHOD This 24-week, three-site, randomized, parallel-groups clinical trial enrolled 124 children, aged 4 through 13 years, with PDDs, accompanied by frequent tantrums, self-injury, and aggression. The children were randomized 3:2 to COMB (n = 75) or MED (n = 49). The participants received risperidone monotherapy from 0.5 to 3.5 mg/day (with switch to aripiprazole if risperidone was ineffective). Parents in the COMB group (n = 75; 60.5%) received a mean of 10.9 PT sessions. The primary measure of compliance was the Home Situations Questionnaire (HSQ) score. RESULTS Primary: intent-to-treat random effects regression showed that COMB was superior to MED on HSQ (p = .006) [effect size at week 24 (d) = 0.34]. The HSQ score declined from 4.31 (± 1.67) to 1.23 (± 1.36) for COMB compared with 4.16 (± 1.47) to 1.68 (± 1.36) for MED. Secondary: groups did not differ on Clinical Global Impressions-Improvement scores at endpoint; compared with MED, COMB showed significant reductions on Aberrant Behavior Checklist Irritability (d = 0.48; p = .01), Stereotypic Behavior (d = 0.23; p = .04), and Hyperactivity/Noncompliance subscales (d = 0.55; p = .04). Final risperidone mean dose for MED was 2.26 mg/day (0.071 mg/kg), compared with 1.98 mg/day for COMB (0.066 mg/kg) (p = .04). CONCLUSIONS Medication plus PT resulted in greater reduction of serious maladaptive behavior than MED in children with PDDs, with a lower risperidone dose.

Concurrent cocaine-ethanol ingestion in humans: pharmacology, physiology, behavior, and the role of cocaethylene.

Simultaneous abuse of cocaine and ethanol is a common occurrence. Cocaethylene, the ethyl ester of benzoylecgonine, has been detected in the urine of patients reporting concurrent use of cocaine and ethanol, and high levels have been found in the blood of victims of fatal drug overdose. This placebo-controlled, double-blind study examined the pharmacokinetic, physiologic, and behavioral effects of dual cocaine and ethanol administration in humans (n=6). Cocaethylene was found in the plasma only after administration of both cocaine and ethanol, and appeared to be eliminated more slowly than cocaine. Plasma cocaine concentrations were significantly higher during cocaine/ethanol administration. Euphorigenic effects were both enhanced and prolonged, and heart rate was significantly increased, following cocaine/ethanol administration as compared to administration of cocaine or ethanol alone.

Pharmacotherapy for posttraumatic stress disorder using phenelzine or imipramine

Sixty male veterans with posttraumatic stress disorder (PTSD) participated in an 8-week, randomized trial comparing phenelzine (N = 19), imipramine (N = 23), and placebo (N = 18). Mean treatment retention was better on phenelzine (7.4 weeks) than on imipramine (5.6 weeks) or placebo (5.5 weeks). By week 5, both medications significantly reduced PTSD symptoms, as assessed by the Impact of Events Scale (IES), but the 44% improvement on phenelzine was greater than the 25% improvement on imipramine. The intrusion, but not the avoidance, subscale of the IES showed significant improvement, and the initial mild to moderate depressive symptoms did not significantly improve.

Risperidone Treatment of Children and Adolescents with Chronic Tic Disorders: A Preliminary Report

OBJECTIVE The purpose of this trial was to investigate the short-term safety and efficacy of risperidone in the treatment of chronic tic disorders in children and adolescents. METHOD This was an 11-week open-label trial and included seven subjects (five boys and two girls) with a mean age of 12.9 +/- 1.9 years. The sample included five patients with Tourettes syndrome and two with chronic motor tic disorder. The children were seen at baseline and for two follow-up visits. Three children had a comorbid diagnosis of obsessive-compulsive disorder (OCD). RESULTS Clinical response, as measured by the Yale Global Tic Severity Scale and the Childrens version of the Yale-Brown Obsessive Compulsive Scale, revealed a statistically significant reduction in tic scores ranging from 26% [corrected] to 66%. One of three children with comorbid OCD showed substantial improvement; the other two subjects showed no change. The most frequent side effect was weight gain, which ranged from 8 to 14 lb. CONCLUSIONS Risperidone, a neuroleptic with both serotonin- and dopamine-blocking properties, appears to be effective in reducing tic frequency and intensity in children and adolescents with chronic tic disorders.

A controlled trial of lithium augmentation in fluvoxamine-refractory obsessive-compulsive disorder: lack of efficacy.

Two- and 4-week double-blind placebo-controlled trials of lithium augmentation of ongoing fluvoxamine treatment trials were conducted in 20 and 10 patients, respectively, with primary obsessive-compulsive disorder (OCD) who had failed to respond to fluvoxamine alone. Although 2 weeks of double-blind lithium augmentation produced a small but statistically significant reduction in obsessive-compulsive symptoms, most patients did not have a clinically meaningful response. Furthermore, there was no statistical or clinical improvement in obsessive-compulsive symptoms during the subsequent 4-week double-blind, placebo-controlled trial of lithium augmentation. On the basis of treatment response criteria, only 18% and 0% of the patients responded to lithium augmentation of fluvoxamine during the 2- and 4-week treatment trials, respectively. In light of the previously reported 44% response rate to lithium augmentation in treatment-resistant depressed patients on fluvoxamine, the results of this study suggest that pathophysiological differences may exist between OCD and depression. The routine use of lithium augmentation in the management of patients with OCD who are refractory to serotonin reuptake inhibitors is not supported by these findings.

Parent-defined target symptoms respond to risperidone in RUPP autism study: customer approach to clinical trials.

OBJECTIVE A consumer-oriented efficacy assessment in clinical trials should measure changes in chief complaint and consumer request (symptoms of most concern to patient/caregiver), which may be diluted in change scores of multisymptom scales. METHOD In the Research Units on Pediatric Psychopharmacology (RUPP) Autism Network 8-week double-blind trial of risperidone versus placebo, the chief concerns of parents were collected at 0, 4, and 8 weeks (endpoint), in addition to standardized primary measures. Blinded clinical judges rated change from baseline to 4 and 8 weeks on a 9-point scale (1 = normalized, 5 = unchanged, 9 = disastrous); 94 participants had usable data. RESULTS The most common symptoms identified by parents were tantrums, aggression, and hyperactivity. Interrater reliability was excellent. Mean ratings at endpoint were 2.8 +/- 1.2 on risperidone and 4.5 +/- 1.3 on placebo (p <.001). Ratings were collinear with Clinical Global Impression-Improvement and Aberrant Behavior Checklist Irritability subscale (primary dimensional measure). Effect size d was 1.4, compared to 1.2 on the Aberrant Behavior Checklist Irritability subscale. Effect sizes varied twofold by symptom category, largest for self-injury (2.11) and tantrums (1.95). CONCLUSIONS Risperidone was superior to placebo in reducing symptoms of most concern to parents of autistic children with irritable behavior. Rating individualized participant-chosen target symptoms seems a reliable, sensitive, efficient, and consumer-friendly way to assess treatment effect and might have clinical application.