Variants of the CNTNAP2 5' promoter as risk factors for autism spectrum disorders: a genetic and functional approach.

Contactin-associated protein-like 2 gene (CNTNAP2), a member of the Neurexin gene superfamily, is one of the best-replicated risk genes for autism spectrum disorders (ASD). ASD are predominately genetically determined neurodevelopmental disorders characterized by impairments of language development, social interaction and communication, as well as stereotyped behavior and interests. Although CNTNAP2 expression levels were proposed to alter ASD risk, no study to date has focused on its 5' promoter. Here, we directly sequenced the CNTNAP2 5' promoter region of 236 German families with one child with ASD and detected four novel variants. Furthermore, we genotyped the three most frequent variants (rs150447075, rs34712024, rs71781329) in an additional sample of 356 families and found nominal association of rs34712024G with ASD and rs71781329GCG[7] with language development. The four novel and the three known minor alleles of the identified variants were predicted to alter transcription factor binding sites (TFBS). At the functional level, the respective sequences spanning these seven variants were bound by nuclear factors. In a luciferase promoter assay, the respective minor alleles showed cell line-specific and differentiation stage-dependent effects at the level of promoter activation. The novel potential rare risk-variant M2, a G>A mutation -215 base pairs 5' of the transcriptional start site, significantly reduced promoter efficiency in HEK293T and in undifferentiated and differentiated neuroblastoid SH-SY5Y cells. This variant was transmitted to a patient with autistic disorder. The under-transmitted, protective minor G allele of the common variant rs34712024, in contrast, increased transcriptional activity. These results lead to the conclusion that the pathomechanism of CNTNAP2 promoter variants on ASD risk is mediated by their effect on TFBSs, and thus confirm the hypothesis that a reduced CNTNAP2 level during neuronal development increases liability for ASD.

New interview and observation measures of the broader autism phenotype: impressions of interviewee measure.

A 20 item observational measure of social functioning, the Impression of Interviewee rating scale, is one of three measures devised to assess the broader autism phenotype. The sample studied included families containing at least two individuals with autism spectrum disorder; observations were undertaken by the researcher who interviewed the subject. An exploratory factor analysis suggested a single factor was most appropriate (Cronbach's α of 0.78). There was a modest but significant retest correlation of 0.42. Correlations between live ratings and blind consensus ratings of vignettes were high (0.93). Correlations with the interview measures were moderate but statistically significant. In conclusion, the observational scale provides a promising start but further work is required before general use can be recommended.

No effect of acute tryptophan depletion on verbal declarative memory in young persons with ADHD.

OBJECTIVE: Animal experiments and studies in adults have shown that the neurotransmitter serotonin (5-HT) plays an important role in learning and memory processes. However, data on this relationship in young persons are scarce, and neurodietary research in this age group is limited compared with the extensive literature on adults. Here, we aimed to explore the effects of a diminished central nervous 5-HT synthesis, which is achieved by acute tryptophan depletion (ATD) Moja-De , on memory function in young males with attention deficit hyperactivity disorder (ADHD). METHOD: Twenty-two male patients with ADHD (ages 9-15 years, mean 10.95 ± 1.17 years) received ATD, thus diminishing central nervous 5-HT synthesis, and a tryptophan-balanced amino acid load (BAL) in a randomized, double-blind, within-subject, crossover design study. Approximately 1.7 h after administration of ATD/BAL, verbal declarative memory was assessed using the 'Auditory Verbal-Learning-Test' (AVLT). RESULTS: There were no significant effects of ATD administration on verbal declarative memory function. CONCLUSION: In this study, changes in 5-HT neurotransmission were not associated with specific aspects of verbal declarative memory in young persons with ADHD. Future studies with healthy control groups that address effects of covarying attentional processes are warranted.

Differences in zinc status and the leptin axis in anorexic and recovered adolescents and young adults: a pilot study.

BACKGROUND: Evidence from animal studies suggests that leptin metabolism is associated with zinc (Zn) status. However, research investigating this relationship in adolescents and young adults with anorexia nervosa (AN) is scarce; the present study aims to fill that gap. METHODS: Serum concentrations of leptin, the soluble leptin receptor (sOB-R) and the free leptin index (FLI) were obtained in healthy control subjects (n=19), acutely ill individuals (n=14) and recovered patients with AN (n=15). Serum Zn concentrations noted in previous research data were also incorporated for all groups. RESULTS: Leptin, FLI and Zn concentrations were higher in recovered subjects with AN when compared with acutely ill AN patients. Remitted patients showed higher sOB-R concentrations but no difference in FLI compared with the control group. Leptin and FLI were lower in the acutely ill patients compared with the control subjects, who showed no differences in Zn concentrations. Zn concentrations were not correlated with leptin, sOB-R or FLI concentrations in any of the three investigated subgroups. CONCLUSIONS: The present investigation does not entirely support an association between Zn, Leptin and FLI concentrations in subjects with AN, possibly due to limited statistical power. Further research and replication of the present findings related to the interaction between leptin and Zn is warranted. However, with respect to serum leptin levels the data of the present investigation indicate that acutely ill and remitted patients with AN differ as regards serum leptin concentrations and FLI, which is in line with previous research.

[Psychopharmacology of autism spectrum disorders]. / Psychopharmakologie autistischer Störungen.

Autism spectrum disorders (ASD) are persistent, heterogeneous conditions that display many comorbid problems. Especially maladaptive behaviours like increased irritability, aggression, impulsivity and self-injurious behaviours are perceived as enormously stressful and can interfere with interventions targeting social and communication deficits. Medication treatments focussing on troubling comorbid problems in ASD can be fundamentally ameliorative, although core features of the disorder itself cannot be sufficiently treated. While atypical antipsychotics and stimulant medication have been proven to be effective in large multisite networks of ASD, serotonin reuptake inhibitors are of limited efficacy. Novel pharmacotherapies to improve social impairment are in the early stages of research.

[Genetic aspects of cognitive abilities across the life span]. / Genetik der kognitiven Fähigkeiten in der Lebensspanne.

Cognitive abilities develop during the first 2 decades and start to decrease in the 6th decade of life. There is strong heritability of general cognitive ability as well as of specific cognitive functions which might increase with age till about age 80. Cognitive disorders derive from this physiological cognitive development; they are also under genetic control. This paper discusses age-specific genetic influences on cognitive functions in interplay with environmental factors and compares these determinants across the life span.

Reduced serotonergic functioning changes heart rate in ADHD.

Reduced mean heart rate (HR) was shown to be a biophysiological marker for aggression, which in turn was proven to be related to changed serotonergic neurotransmission. A total of 16 ADHD-diagnosed boys were subjected to rapid tryptophan depletion (RTD) and a placebo in a double-blind within-subject crossover-design. Mean HR was assessed under RTD/placebo. Low impulsive patients behaving aggressively under RTD showed a lowered HR under RTD versus placebo. Diminished 5-HT functioning was associated with lowered HR and aggressive behaviour.

Calendar calculating in savants with autism and healthy calendar calculators.

BACKGROUND: Calendar calculation is the ability to quickly name the day that a given date falls on. Previous research has suggested that savant calendar calculation is based on rote memory and the use of rule-based arithmetic skills. The objective of this study was to identify the cognitive processes that distinguish calendar calculation in savant individuals from healthy calendar calculators. METHOD: Savant calendar calculators with autism (ACC, n=3), healthy calendar calculators (HCC, n=3), non-savant subjects with autism (n=6) and healthy calendar calculator laymen (n=18) were included in the study. All participants calculated dates of the present (current month). In addition, ACC and HCC also calculated dates of the past and future 50 years. RESULTS: ACC showed shorter reaction times and fewer errors than HCC and non-savant subjects with autism, and significantly fewer errors than healthy calendar calculator laymen when calculating dates of the present. Moreover, ACC performed faster and more accurate than HCC regarding past dates. However, no differences between ACC and HCC were detected for future date calculation. CONCLUSIONS: The findings may imply distinct calendar calculation strategies in ACC and HCC, with HCC relying on calendar regularities for all types of dates and an involvement of (rote) memory in ACC when processing dates of the past and the present.

Diminished 5-HT functioning in CBCL pediatric bipolar disorder-profiled ADHD patients versus normal ADHD: susceptibility to rapid tryptophan depletion influences reaction time performance.

OBJECTIVE: There is a current debate on characterizing children with pediatric bipolar disorder (PBD) through a profile within the child behaviour checklist (CBCL), and on the involvement of the 5-HT system in the underlying neurobiological processes of PBD. The aim of the present paper was to investigate reaction time performance in patients with CBCL-PBD and to discriminate ADHD from ADHD with CBCL-PBD with respect to diminished 5-HT functioning and reaction time. METHODS: Twenty-two patients with ADHD received the rapid tryptophan depletion test (RTD) thus lowering the central-nervous 5-HT synthesis rate within a placebo-controlled double-blind within-subject crossover design. Reaction time was assessed using a competitive reaction time game with low and high provocation after both depletion and placebo intake. The study sample was divided into high and low scorers according to their CBCL-PBD scores. RESULTS: Comparing those six patients with the highest and clinically significant CBCL-PBD scores versus those six patients with the lowest, patients with a high CBCL-PBD score showed a slower reaction time under RTD compared to patients with low CBCL-PBD scores after high provocation. CBCL-'aggression' discriminated between the two groups. CONCLUSIONS: The results suggest alterations in 5-HT functioning in CBCL-PBD-spectrum patients, and 'aggression' as a potential moderator variable to ADHD.

Diminished serotonergic functioning in hostile children with ADHD: tryptophan depletion increases behavioural inhibition.

INTRODUCTION: Serotonergic (5-HT) functioning has been shown to account for a variety of behavioural characteristics, in particular aggressive and impulsive behaviour. This study explored the effects of rapid tryptophan depletion (RTD) and the ensuing reduction of brain 5-HT synthesis on behavioural inhibition in passive avoidance learning assessed in a computerized go/no-go task. METHODS: 22 male patients with an ICD-10 diagnosis of ADHD were administered RTD within an amino acid drink lacking tryptophan, the natural precursor of 5-HT, thus lowering the central nervous 5-HT synthesis rate in a placebo-controlled double-blind within-subject crossover-design. 4 hours after RTD/placebo intake the patients were subjected to a go/no-go task for assessment of behavioural inhibition. RESULTS: Highly hostile aggressive patients showed increased inhibition errors under RTD compared to placebo. Low hostile aggressive patients showed lower rates of inhibition errors and thus better performance under RTD compared to placebo. DISCUSSION: The data suggest that in ADHD levels of trait-aggressive characteristics influence the susceptibility to changed behavioural inhibition after an acute 5-HT dysfunction. The detected influence of 5-HT could also be relevant as regards behavioural inhibition being subject to a developmental change in 5-HT functioning.

No increase in long-term risk for nicotine use disorders after treatment with methylphenidate in children with attention-deficit/hyperactivity disorder (ADHD): evidence from a non-randomised retrospective study.

OBJECTIVE: To evaluate long-term effects of methylphenidate (MPH) treatment in ADHD children on the development of nicotine use disorders (SUD-N). METHODS: Multisite retrospective non-randomised longitudinal study with 215 ADHD children (diagnosis at 9.2 years of age; reassessment for SUD-N at 21.9 years of age) strictly parallel allocated to MPH treated (n = 106) and drug naive (n = 109) children. RESULTS: There was no difference between the groups with respect to frequency (84% MPH; 89% non-MPH; chi(2) = 1.6; p = 0.21) and age of onset for first cigarette smoking (log rank 1.68; p = 0.19). Continuous smoking was reached by 51% (MPH) and 61% (non-MPH) of the patients. Survival analyses revealed a small and nominally significant delay in age of onset for continuous smoking in the MPH-group (log rank = 3.85; p = 0.049). Nicotine dependency was reached by 20% (MPH) and 27% (non-MPH). Age of onset does not differ between groups (log rank = 2.24; p = 0.13). DISCUSSION: Limited evidence due to the non-randomised nature of the study is given that MPH does not induce SUD-N. The data suggests there may be a beneficial effect of MPH on delay of onset for continuous nicotine consumption in ADHD patients.

Reduced number of taste papillae in patients with eating disorders.

Taste affects dietary behavior and in turn taste response and food preferences are altered in eating disorders. Fungiform papillae on the tongue are the first line of the gustatory apparatus to provide information about taste. Aim of this study is determination of their number in patients with eating disorders. Twenty-seven female adolescents with eating disorders and 16 age-matched healthy female controls were examined. Tongues were stained with blue food coloring and the number of fungiform papillae was quantified using digital photography and image processing. Patients with restrictive type eating disorders showed a more distinct reduction (p < 0.001) of fungiform papillae than patients with vomiting and/or binge eating (p < 0.05), compared with those of healthy control subjects. Causes may be an initially disturbed development of fungiform papillae or secondary to changes in eating behavior which may be mutually causative.

An fMRI-study of locally oriented perception in autism: altered early visual processing of the block design test.

Autism has been associated with enhanced local processing on visual tasks. Originally, this was based on findings that individuals with autism exhibited peak performance on the block design test (BDT) from the Wechsler Intelligence Scales. In autism, the neurofunctional correlates of local bias on this test have not yet been established, although there is evidence of alterations in the early visual cortex. Functional MRI was used to analyze hemodynamic responses in the striate and extrastriate visual cortex during BDT performance and a color counting control task in subjects with autism compared to healthy controls. In autism, BDT processing was accompanied by low blood oxygenation level-dependent signal changes in the right ventral quadrant of V2. Findings indicate that, in autism, locally oriented processing of the BDT is associated with altered responses of angle and grating-selective neurons, that contribute to shape representation, figure-ground, and gestalt organization. The findings favor a low-level explanation of BDT performance in autism.

CBCL-pediatric bipolar disorder phenotype: severe ADHD or bipolar disorder?

BACKGROUND: In children with pediatric bipolar disorder (PBD), a consistent pattern of elevations in hyperactivity, depression/anxiety, and aggression has been identified on the child behavior checklist (CBCL-PBD profile). The aim of the present study was to estimate the prevalence of the CBCL-PBD profile in a child psychiatric sample, and to determine ICD-10 diagnoses in CBCL-PBD patients. METHODS: We studied a sample of 939 consecutively referred children and adolescents, aged 4-18 years. ICD-10 discharge diagnoses were established in consensus conferences. The CBCL 4-18 was completed by parents as part of the diagnostic routine. RESULTS: A total of 62 subjects (6.6%; 95% CI=5.2-8.4) met criteria for the CBCL-PBD phenotype. More than 75% of CBCL-PBD subjects were clinically diagnosed with disruptive behavior disorders (ADHD, ODD, and CD). Two patients (0.2% of the total sample) received a formal diagnosis of bipolar disorder, but did not show the CBCL-PBD phenotype. CONCLUSIONS: A considerable number of children in Germany are referred to psychiatric care with a mixed phenotype of aggression, anxiety, depression and attention problems. Our study demonstrated a comparable prevalence and similar clinical characteristics as reported from other countries using different diagnostic approaches. However, the CBCL-PBD phenotype does not correspond with clinical consensus diagnoses of bipolar disorder, but with severe disruptive behavior disorders.

Long-acting methylphenidate has an effect on aggressive behavior in children with attention-deficit/hyperactivity disorder.

INTRODUCTION: Aggression is frequently observed in children and adolescents with attention-deficit/hyperactivity disorder (ADHD). The aim of this study was to assess the efficacy with regard to oppositional and aggressive behavior of a new long-acting methylphenidate preparation (Medikinet retard, MPH-MR), with equal portions of the immediate-release and the sustained-release active substance, and especially to look at correlations between either teacher or parent assessment of aggression and ADHD sub-symptomatology. METHODS: Eighty five children and adolescents (6-16 years) were investigated in a double-blind, randomized, clinical trial over 5 weeks under a treatment with MPH-MR using symptom checklists for ADHD, oppositional-defiant and conduct disorder according to the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV). RESULTS: A total of 64.9% of the children showed oppositional defiant disorder/conduct disorder (ODD/CD) symptoms. A statistically significant effect was found in the group treated with MPH (verum-group). On the basis of Cohen's criteria, high effects were found for aggressive symptoms in school (d = 1.0), but not in the afternoon (d = 0.4). There were also lower effect sizes for more severe aggressive symptoms. We found characteristic correlations between ODD/CD symptoms and the ADHD subscale hyperactivity/impulsivity compared to the subscale inattention. CONCLUSIONS: Long-acting MPH is effective in the treatment of oppositional-defiant and aggressive behavior, especially concerning milder symptoms. The expected correlation between impulsivity and aggressiveness could be confirmed.

[Therapeutic options in autism]. / Therapieansätze bei kindlichem Autismus. So lässt sich soziale Kompetenz trainieren.

The etiology of autistic disorders is very probably genetic. The aim of treatment is to improve the child's ability to interact and communicate with others, as well as his language skills. For this purpose, various therapeutic behavioral options are available. In the case of the Frankfurt group therapy, group therapy is combined with special computer-based training aimed at identifying emotions. This can be supplemented by psychopharmaceutic co-treatment aimed at ameliorating accompanying dysfunctional behaviors, such as auto-aggression, hyperactivity, or motor stereotypes.

[The importance of choline and different serum parameters for the course of the anorexia nervosa]. / Die Bedeutung von Cholin und verschiedenen Serumparametern für den Verlauf der Anorexia nervosa.

Malnutrition in anorexia nervosa was simulated in an animal starvation study. Female rats aged 11 to 13 weeks received a hypocaloric standard diet or a hypocaloric choline reduced diet. Weight reduction lasted for 12 to 20 weeks and was between 30 % to 40 % of initial weight. Several animals were refed after weight reduction up to 6 to 12 weeks with a standard or a choline enriched diet ad libitum. Serum parameters and membrane fluidity of the CNS were measured after weight reduction or after refeeding. Weight reduction leads to a significant decrease of serum protein, triglycerides (Z = -3.53 resp. -3.42; p < 0.001) and an increase of membrane fluidity in the CNS (Z = -2.83; p < 0.001). Long-term diet with marked weight reduction and following refeeding causes a catabole metabolic situation with significant increase of urea/creatinine-ratio. Choline enriched refeeding after diet results in normalization of serum parameters and membrane fluidity of the CNS. Choline enrichment leads to a significant increase of serum protein (Z = -2.03; p < 0.01). Besides we found a negative correlation between serum protein and urea/creatinine-ratio (r (S) = -0.47; p < 0.001; n = 64). This is possibly caused by a reduced protein catabolism or an increased protein anabolism. Furthermore membrane fluidity in the CNS correlates with serum protein (r (S) = 0.65; p < 0.001; n = 41) and with serum creatinine levels (r (S) = 0.58; p < 0.001; n = 42). We conclude that these serum parameters are potential predictors for cell function in the starved brain and consequently for the course of anorexia nervosa. We furthermore hypothesize that choline enriched nutrition after starvation improves the stabilization of cerebral membranes and the metabolic situation in anorexia nervosa.