Polygenic association between attention-deficit/hyperactivity disorder liability and cognitive impairments

BACKGROUND

A recent genome-wide association study (GWAS) identified 12 independent loci significantly associated with attention-deficit/hyperactivity disorder (ADHD). Polygenic risk scores (PRS), derived from the GWAS, can be used to assess genetic overlap between ADHD and other traits. Using ADHD samples from several international sites, we derived PRS for ADHD from the recent GWAS to test whether genetic variants that contribute to ADHD also influence two cognitive functions that show strong association with ADHD: attention regulation and response inhibition, captured by reaction time variability (RTV) and commission errors (CE).

METHODS

The discovery GWAS included 19 099 ADHD cases and 34 194 control participants. The combined target sample included 845 people with ADHD (age: 8-40 years). RTV and CE were available from reaction time and response inhibition tasks. ADHD PRS were calculated from the GWAS using a leave-one-study-out approach. Regression analyses were run to investigate whether ADHD PRS were associated with CE and RTV. Results across sites were combined via random effect meta-analyses.

RESULTS

When combining the studies in meta-analyses, results were significant for RTV (R² = 0.011, β = 0.088, p = 0.02) but not for CE (R² = 0.011, β = 0.013, p = 0.732). No significant association was found between ADHD PRS and RTV or CE in any sample individually (p > 0.10).

CONCLUSIONS

We detected a significant association between PRS for ADHD and RTV (but not CE) in individuals with ADHD, suggesting that common genetic risk variants for ADHD influence attention regulation.

AB1435 CLINICAL PREDICTION MODELS FOR METHOTREXATE OUTCOMES IN PATIENTS WITH RHEUMATOID ARTHRITIS: SYSTEMATIC REVIEW AND CRITICAL APPRAISAL

Background

Methotrexate (MTX) is the preferred first line therapy for rheumatoid arthritis (RA). MTX has several advantages over other treatments including effectiveness and low cost; however, around 40% of patients are classed as non-responders after 6 months (1). Therefore, there is a clinical need to identify patients at high-risk of poor outcomes, such that patients could potentially be fast tracked onto alternative therapies to improve their clinical outcomes and quality of life. Such risk stratification is possible through prognostic prediction models, although models which have previously been developed appear to have had little impact on practice. This may be in part due to methodological features of their development and validation but, to date, no review has collated the evidence in this field.

Objectives

This systematic review aimed to (i) identify and summarise multivariable prediction models of MTX treatment outcomes in biologic-naïve adult RA patients, and (ii) critically appraise their methodological properties.

Methods

The electronic databases Medline and Embase were searched to identify studies developing or validating prediction models of MTX outcomes in the population of interest, including demographic, disease-specific or treatment-related covariates, published after 2005. Models were stratified by outcome definition, and information on participants, predictors, model performance, handling of missing data and model validation were extracted. A risk of bias (ROB) assessment using PROBAST (prediction model risk of bias assessment tool) was carried out. Two reviewers were independently involved in screening, data extraction, and ROB stages.

Results

The included studies used three main outcome definitions: a state of disease activity, such as low disease activity or remission; the EULAR response criteria; or discontinuation due to adverse events (AEs). Some studies incorporated AEs into a composite outcome with disease activity and few accounted for potential competing risks, which are events that preclude the occurrence of the primary outcome of interest. Not handling competing risks may result in under-prediction, leading to potentially compromised risk stratification. There was a lack of internal validation using cross sampling techniques, which is critical for reducing overfitting, as well as external validation in new data, a process necessary to ensure reproducibility and generalisability of a prediction model to the larger patient population. Missing data was mostly handled using complete case analysis, leading to potentially biased risk estimates. The ROB assessment showed overall high ROB of the included studies.

Conclusion

This systematic review summarises current prediction models of MTX treatment outcomes in RA. It highlights several methodological shortcomings, such as poor handling of missing data and competing risks to the primary outcome, and a lack of internal and external validation. These should be addressed in future model development and validation to improve accuracy of predictions. Without tackling these issues, prediction of MTX treatment outcomes will remain at high risk of bias and should not be recommended for informing risk stratification for RA treatment decisions.

References

[1]Sergeant JC, Hyrich KL, Anderson J, Kopec-Harding K, Hope HF, Symmons DPM, et al. Prediction of primary non-response to methotrexate therapy using demographic, clinical and psychosocial variables: Results from the UK Rheumatoid Arthritis Medication Study (RAMS). Arthritis Res Ther. 2018;20(1):1–11.

Disclosure of Interests

Celina Gehringer: None declared, Glen Martin: None declared, Kimme Hyrich Speakers bureau: Abbvie, Grant/research support from: BMS and Pfizer, Suzanne Verstappen: None declared, Jamie Sergeant: None declared

Factor structure and cultural factors of disruptive behaviour disorders symptoms in Italian children

Objective:

Poor parent and teacher awareness for attention-deficit/hyperactivity disorder (ADHD) and the scepticism of many clinicians on the prevalence of the disorder, make Italy an interesting environment in which to verify neuropsychological constructs generated in a predominantly Northern American cultural contest. The aim of the study was to verify, by factor confirmatory analysis, the empirical validity of the DSM constructs underlying the diagnostic criteria for developmental disruptive behaviour disorders in Italian school-age children.

Methods:

Scores for DSM-IV inattention and hyperactivity/impulsivity, for oppositional defiant disorder (ODD) and for conduct disorder (CD) symptoms in 6–12 years old Italian children were analysed from 1575 parent and 1085 teacher forms of the disruptive behaviour disorders questionnaires collected in four different Italian regions.

Results:

Reliability indicates high internal consistencies for both parent and teacher rating of inattention, hyperactivity/impulsivity, and oppositionality, but not for conduct problems. In accordance with the literature, a relatively low inter-rater convergent and discriminant validity correlation was observed comparing measures obtained by between parents and teachers. Confirmatory factor analysis of both parent and teacher data showed a better fit for a four-factor model, indicating a factor structure in accordance with the DSM-IV taxonomy. When completed by parents and teachers of clinically assessed ADHD, dyslexic or normal children, the disruptive behavioural disorder questionnaires showed a significant predictive diagnostic value.

Conclusion:

Although an informant variance higher that dimensional (trait) variance was observed, the study provides support for DSM-IV taxonomy for developmental disruptive disorders, showing construct validity of ADHD. ODD and CD could also be distinguished from each other.

Shift working reduces operative experience for trauma and orthopaedic higher surgical trainees: a UK multicentre study

INTRODUCTION

In recent years there has been a rise in the number of trauma and orthopaedics trainees working on full shift patterns. Historically, most trauma and orthopaedics trainees worked 24 hours non-resident on-call shifts. The effect of this change in shift patterns has not previously been measured. As two trusts (one trauma unit, one major trauma centre) in our region underwent a change to full shift working, we assessed the impact on the trainees' operating experience.

METHODS

Fifty-five logbooks were analysed across the two trusts over a two-year period, with comparisons made between pre- and post-shift working.

RESULTS

Overall operating fell by 13% for trainees working full shift patterns, which was statistically significant. There was a loss of elective operating of 15% at the trauma unit and 32% at the major trauma centre for trainees doing shift work. The effect on trauma operating opportunities was mixed. Index operating was largely preserved.

CONCLUSIONS

Shift working significantly impacts on surgical training opportunities. We explore approaches to minimising this effect.

Eating Disorders Impact on Vigilance and Decision Making of a Community Sample of Treatment Naive Attention-Deficit/Hyperactivity Disorder Young Adults

Although impulsivity is suggested as a possible link to explain the association of Attention-Deficit/Hyperactivity Disorder (ADHD) with an Eating Disorder (ED), there is little research on how clinical and cognitive/neuropsychological functioning might change when this comorbidity occurs. ADHD individuals are at a higher of developing ED and also obesity. Some research has described the impact of ADHD in clinical treatment-seeking samples of ED patients. Consequently, we investigated how ED impacted on clinical and cognitive variables of a community sample of treatment-naive ADHD individuals. Ninety college students arranged in three groups (ADHD+ED, ADHD only and Controls) were analyzed using semi-structured interviews for ADHD (K-SADS), the Iowa Gambling Task, the Conner's Continuous Performance Test, Digit and Visual span, as well as rating scales for anxiety (STAI), depression (BDI) and impulsivity (BIS-11), and binge eating (BES). We found that ADHD+ED individuals significantly differed from both groups, presenting with a higher body mass index; more hyperactivity-impulsivity symptoms; higher binge eating scores; more omission errors on the Continuous Performance Test; disadvantageous choices on the Iowa Gambling Task. Also, we demonstrated through a moderation/mediation analysis that a greater level of binge eating mediated the increases in body mass index on our sample. There were no significant paths to explain binge-eating severity through changes on any of the neuropsychological tests used. The presence of an ED in normal weight in a community sample of ADHD individuals is associated with higher body mass index and a worse cognitive functioning.

Revisiting the co-existence of Attention-Deficit/Hyperactivity Disorder and Chronic Tic Disorder in childhood-The case of colour discrimination, sustained attention and interference control

Objective

Attention Deficit / Hyperactivity Disorder (ADHD) and Chronic Tic Disorder (CTD) are two common and frequently co-existing disorders, probably following an additive model. But this is not yet clear for the basic sensory function of colour processing sensitive to dopaminergic functioning in the retina and higher cognitive functions like attention and interference control. The latter two reflect important aspects for psychoeducation and behavioural treatment approaches.

Methods

Colour discrimination using the Farnsworth-Munsell 100-hue Test, sustained attention during the Frankfurt Attention Inventory (FAIR), and interference liability during Colour- and Counting-Stroop-Tests were assessed to further clarify the cognitive profile of the co-existence of ADHD and CTD. Altogether 69 children were classified into four groups: ADHD (N = 14), CTD (N = 20), ADHD+CTD (N = 20) and healthy Controls (N = 15) and compared in cognitive functioning in a 2×2-factorial statistical model.

Results

Difficulties with colour discrimination were associated with both ADHD and CTD factors following an additive model, but in ADHD these difficulties tended to be more pronounced on the blue-yellow axis. Attention problems were characteristic for ADHD but not CTD. Interference load was significant in both Colour- and Counting-Stroop-Tests and unrelated to colour discrimination. Compared to Controls, interference load in the Colour-Stroop was higher in pure ADHD and in pure CTD, but not in ADHD+CTD, following a sub-additive model. In contrast, interference load in the Counting-Stroop did not reveal ADHD or CTD effects.

Conclusion

The co-existence of ADHD and CTD is characterized by additive as well as sub-additive performance impairments, suggesting that their co-existence may show simple additive characteristics of both disorders or a more complex interaction, depending on demand. The equivocal findings on interference control may indicate limited validity of the Stroop-Paradigm for clinical assessments.

The risk of eating disorders comorbid with attention-deficit/hyperactivity disorder: A systematic review and meta-analysis

OBJECTIVE

There has been interest in whether people with Attention-Deficit/Hyperactivity Disorder (ADHD) are at higher risk of developing an Eating Disorder (ED). The aim of this study was estimate the size of this association with a meta-analysis of studies.

METHODS

We retrieved studies following PRISMA guidelines from a broad range of databases.

RESULTS

Twelve studies fitted our primary aim in investigating ED in ADHD populations (ADHD = 4,013/Controls = 29,404), and five exploring ADHD in ED populations (ED = 1,044/Controls = 11,292). The pooled odds ratio of diagnosing any ED in ADHD was increased significantly, 3.82 (95% CI:2.34-6.24). A similar level of risk was found across all ED syndromes [Anorexia Nervosa = 4.28 (95% CI:2.24-8.16); Bulimia Nervosa = 5.71 (95% CI: 3.56-9.16) and Binge Eating Disorder = 4.13 (95% CI:3-5.67)]. The risk was significantly higher if ADHD was diagnosed using a clinical interview [5.89 (95% CI:4.32-8.04)] rather than a self-report instrument [2.23 (95% CI:1.23-4.03)]. The pooled odds ratio of diagnosing ADHD in participants with ED was significantly increased, 2.57 (95% CI:1.30-5.11). Subgroup analysis of cohorts with binge eating only yielded a risk of 5.77 (95% CI:2.35-14.18). None of the variables examined in meta-regression procedures explained the variance in effect size between studies.

DISCUSSION

People with ADHD have a higher risk of comorbidity with an ED and people with an ED also have higher levels of comorbidity with ADHD. Future studies should address if patients with this comorbidity have a different prognosis, course and treatment response when compared to patients with either disorder alone.

RESUMEN OBJETIVO

Ha habido interés en saber si la gente con Trastorno por Déficit de Atención e Hiperactividad (TDAH) están en mayor riesgo de desarrollar un Trastorno de la Conducta Alimentaria (TCA). El objetivo de este estudio fue estimar el tamaño de esta asociación con un meta-análisis de los estudios. Métodos: Recuperamos estudios de una amplia gama base de datos,  que siguen los lineamientos PRISMA. Resultados: Doce estudios encajaron con nuestro objetivo primario de investigar los TCA en poblaciones con TDAH (TDAH = 4,013/Controles = 29,404), y 5 exploraron TDAH en poblaciones con TCA (TCA = 1,044/Controles = 11,292). El odds ratio (OR) agrupado de diagnosticar cualquier TCA en el TDAH se incrementó significativamente, 3.82 (95% CI:2.34-6.24). Un nivel de riesgo similar fue encontrado en todos los síndromes de TCA [Anorexia Nervosa = 4.28 (95% CI:2.24-8.16); Bulimia Nervosa = 5.71 (95% CI:3.56-9.16) y Trastorno por Atracón = 4.13 (95% CI: 3-5.67)]. El riesgo fue significativamente mayor si el TDAH fue diagnosticado utilizando una entrevista clínica [5.89 (95% CI:4.32-8.04)] en lugar de un instrumento de auto-reporte [2.23 (95% CI:1.23-4.03)]. El odds ratio (OR) agrupado de diagnosticar TDAH en participantes con TCA fue significativamente incrementado, 2.57 (95% CI:1.30-5.11). El análisis de los subgrupos de cohort con atracones solamente produjo un riesgo de 5.77 (95% CI:2.35-14.18). Ninguna de las variables examinadas en los procedimientos de meta-regresión explicaron la varianza en el tamaño del efecto entre los estudios. Discusión: La gente con TDAH tiene un mayor riesgo de comorbilidad con un TCA y la gente con un TCA también tiene niveles altos de comorbilidad con TDAH. Los estudios futuros deberán abordar si los pacientes con esta comorbilidad tienen diferente pronóstico, curso y respuesta a tratamiento cuando son comparados con pacientes que solamente tienen uno de los trastornos.  © 2016 Wiley Periodicals, Inc. (Int J Eat Disord 2016) © 2016 Wiley Periodicals, Inc. (Int J Eat Disord 2016; 49:1045-1057).

ADHD Rate in Obese Women With Binge Eating and Bulimic Behaviors From a Weight-Loss Clinic

OBJECTIVE

Few studies have demonstrated a possible association between ADHD and obesity in adults. The aim of this study was to investigate the prevalence of ADHD in a sample of obese women seeking treatment, and its relations with binge eating and bulimic behaviors.

METHOD

We performed a cross-sectional study in a clinical sample of one hundred fifty-five women, with a mean age of 38.9 (+10.7) years and a mean body mass index (BMI) of 39.2 (+5.29). Participants were evaluated with semistructured interviews and completed self-report psychiatric rating scales.

RESULTS

The rate of ADHD in the sample was of 28.3%. The presence of ADHD was significantly correlated with more severe binge eating, bulimic behaviors, and depressive symptomatology.

CONCLUSION

Similar to previous studies, a higher than expected rate of ADHD was observed among obese women. ADHD in obese individuals may be a risk factor for greater severity of disordered eating patterns.

Neurocognitive predictors of substance use disorders and nicotine dependence in ADHD probands, their unaffected siblings, and controls: a 4-year prospective follow-up

BACKGROUND

Attention-Deficit/Hyperactivity Disorder (ADHD) is a risk factor for substance use disorders (SUDs) and nicotine dependence (ND). Neurocognitive deficits may predict the increased risk of developing SUDs and nicotine dependence.

METHODS

This study comprised three groups derived from the Dutch part of the International Multicenter ADHD Genetics (IMAGE) study: ADHD probands (n = 294), unaffected siblings (n = 161), and controls (n = 214). At baseline (age = 12.2), a range of neurocognitive functions was assessed including executive functions (inhibition, working memory, timing), measures of motor functioning (motor timing and tracking) and IQ. After a mean follow-up of 4.2 years, SUDs and ND were assessed.

RESULTS

None of the neurocognitive functions predicted later SUDs or ND in ADHD probands, even after controlling for medication use and conduct disorder. Slower response inhibition predicted later nicotine dependence in unaffected siblings (OR = 2.06, 95% CI = 1.22-3.48), and lower IQ predicted increased risk for SUDs in controls (OR = 1.96, 95% CI = 1.12-3.44).

CONCLUSIONS

Cold executive functions, motor functioning, and IQ did not predict the elevated risk of SUDs and ND in ADHD. Future studies should target 'hot' executive functions such as reward processing as risk factors for SUDs or ND.

Mechanisms underpinning inattention and hyperactivity: neurocognitive support for ADHD dimensionality

BACKGROUND

Taxometric and behavioral genetic studies suggest that attention deficit hyperactivity disorder (ADHD) is best modeled as a dimension rather than a category. We extended these analyses by testing for the existence of putative ADHD-related deficits in basic information processing (BIP) and inhibitory-based executive function (IB-EF) in individuals in the subclinical and full clinical ranges. Consistent with the dimensional model, we predicted that ADHD-related deficits would be expressed across the full spectrum, with the degree of deficit linearly related to the severity of the clinical presentation.

METHOD

A total of 1547 children (aged 6-12 years) participated in the study. The Development and Well-Being Assessment (DAWBA) was used to classify children into groups according to levels of inattention and hyperactivity independently: (1) asymptomatic, (2) subthreshold minimal, (3) subthreshold moderate and (4) clinical ADHD. Neurocognitive performance was evaluated using a two-choice reaction time task (2C-RT) and a conflict control task (CCT). BIP and IB-EF measures were derived using a diffusion model (DM) for decomposition of reaction time (RT) and error data.

RESULTS

Deficient BIP was found in subjects with minimal, moderate and full ADHD defined in terms of inattention (in both tasks) and hyperactivity/impulsivity dimensions (in the 2C-RT). The size of the deficit increased in a linear manner across increasingly severe presentations of ADHD. IB-EF was unrelated to ADHD.

CONCLUSIONS

Deficits in BIP operate at subclinical and clinical levels of ADHD. The linear nature of this relationship provides support for a dimensional model of ADHD in which diagnostic thresholds are defined in terms of clinical and societal burden rather than representing discrete pathophysiological states.

When self-report diverges from performance: the usage of BIS-11 along with neuropsychological tests

Impulsivity has been fractionated into multiple independent, but correlated, components. Personality and neuropsychological studies have consistently shown its multidimensional nature. Each theoretical approach uses different techniques such as self-report questionnaires and neuropsychological tests to assess impulsivity, respectively. Our main objective was to investigate if there is evidence of convergent validity for impulsivity as assessed by both types of measures. We administered the Barratt Impulsivity Scale 11 and two neuropsychological tests (Iowa Gambling Task and Continuous Performance Task) to 266 participants to measure inhibition control and non-planning impulsivity dimensions. Results from an exploratory factorial analysis and group comparison indicated there was little evidence of convergent validity between the two types of measures. These findings are discussed in terms of impulsivity as a multi-factorial construct as well as the specific instruments used for assessment. Implications for psychological theory and impulsivity assessment were also proposed.

Influence of attention-deficit/hyperactivity disorder on binge eating behaviors and psychiatric comorbidity profile of obese women

OBJECTIVE

Previous studies have reported higher prevalence rates of attention-deficit/hyperactivity disorder (ADHD) both in eating disorders (ED) and in obese patients. We compared the psychiatric comorbidity profile of obese ADHD women with non-ADHD obese women and how ADHD symptoms impact in binge eating behaviors.

DESIGN

Cross-sectional study of a clinical sample.

SUBJECTS

171 adult women were evaluated at a specialized clinic in obesity and ED.

MEASUREMENTS

Participants complete a semi-structured interview and psychopathology rating scales. A hierarchical regression model was employed to predict binge eating behavior.

RESULTS

Obese ADHD patients had a larger number of psychiatric comorbidities (p<0.001), especially Substance Abuse Disorders, and higher scores on psychopathology rating scales (p<0.05). The highest prediction for binge eating in the regression model was the presence of depressive symptoms, followed by ADHD inattention symptoms and trait-impulsivity.

CONCLUSION

ADHD should be routinely evaluated in obese since it is related with more severe psychopathology. Depressive symptoms can predict the presence of binge eating in obese patients.

Specificity of basic information processing and inhibitory control in attention deficit hyperactivity disorder

BACKGROUND

Both inhibitory-based executive functioning (IB-EF) and basic information processing (BIP) deficits are found in clinic-referred attention deficit hyperactivity disorder (ADHD) samples. However, it remains to be determined whether: (1) such deficits occur in non-referred samples of ADHD; (2) they are specific to ADHD; (3) the co-morbidity between ADHD and oppositional defiant disorder/conduct disorder (ODD/CD) has additive or interactive effects; and (4) IB-EF deficits are primary in ADHD or are due to BIP deficits.

METHOD

We assessed 704 subjects (age 6-12 years) from a non-referred sample using the Development and Well-Being Assessment (DAWBA) and classified them into five groups: typical developing controls (TDC; n = 378), Fear disorders (n = 90), Distress disorders (n = 57), ADHD (n = 100), ODD/CD (n = 40) and ADHD+ODD/CD (n = 39). We evaluated neurocognitive performance with a Two-Choice Reaction Time Task (2C-RT), a Conflict Control Task (CCT) and a Go/No-Go (GNG) task. We used a diffusion model (DM) to decompose BIP into processing efficiency, speed-accuracy trade-off and encoding/motor function along with variability parameters.

RESULTS

Poorer processing efficiency was found to be specific to ADHD. Faster encoding/motor function differentiated ADHD from TDC and from fear/distress whereas a more cautious (not impulsive) response style differentiated ADHD from both TDC and ODD/CD. The co-morbidity between ADHD and ODD/CD reflected only additive effects. All ADHD-related IB-EF classical effects were fully moderated by deficits in BIP.

CONCLUSIONS

Our findings challenge the IB-EF hypothesis for ADHD and underscore the importance of processing efficiency as the key specific mechanism for ADHD pathophysiology.

Nonpharmacological interventions for ADHD: systematic review and meta-analyses of randomized controlled trials of dietary and psychological treatments

OBJECTIVE

Nonpharmacological treatments are available for attention deficit hyperactivity disorder (ADHD), although their efficacy remains uncertain. The authors undertook meta-analyses of the efficacy of dietary (restricted elimination diets, artificial food color exclusions, and free fatty acid supplementation) and psychological (cognitive training, neurofeedback, and behavioral interventions) ADHD treatments.

METHOD

Using a common systematic search and a rigorous coding and data extraction strategy across domains, the authors searched electronic databases to identify published randomized controlled trials that involved individuals who were diagnosed with ADHD (or who met a validated cutoff on a recognized rating scale) and that included an ADHD outcome.

RESULTS

Fifty-four of the 2,904 nonduplicate screened records were included in the analyses. Two different analyses were performed. When the outcome measure was based on ADHD assessments by raters closest to the therapeutic setting, all dietary (standardized mean differences=0.21-0.48) and psychological (standardized mean differences=0.40-0.64) treatments produced statistically significant effects. However, when the best probably blinded assessment was employed, effects remained significant for free fatty acid supplementation (standardized mean difference=0.16) and artificial food color exclusion (standardized mean difference=0.42) but were substantially attenuated to nonsignificant levels for other treatments.

CONCLUSIONS

Free fatty acid supplementation produced small but significant reductions in ADHD symptoms even with probably blinded assessments, although the clinical significance of these effects remains to be determined. Artificial food color exclusion produced larger effects but often in individuals selected for food sensitivities. Better evidence for efficacy from blinded assessments is required for behavioral interventions, neurofeedback, cognitive training, and restricted elimination diets before they can be supported as treatments for core ADHD symptoms.

Practitioner review: current best practice in the management of adverse events during treatment with ADHD medications in children and adolescents

BACKGROUND

Medication is an important element of therapeutic strategies for ADHD. While medications for ADHD are generally well-tolerated, there are common, although less severe, as well as rare but severe adverse events AEs during treatment with ADHD drugs. The aim of this review is to provide evidence- and expert-based guidance concerning the management of (AEs) with medications for ADHD.

METHODS

For ease of use by practitioners and clinicians, the article is organized in a simple question and answer format regarding the prevalence and management of the most common AEs. Answers were based on empirical evidence from studies (preferably meta-analyses or systematic reviews) retrieved in PubMed, Ovid, EMBASE and Web of Knowledge through 30 June 2012. When no empirical evidence was available, expert consensus of the members of the European ADHD Guidelines Group is provided. The evidence-level of the management recommendations was based on the SIGN grading system.

RESULTS

The review covers monitoring and management strategies of loss of appetite and growth delay, cardiovascular risks, sleep disturbance, tics, substance misuse/abuse, seizures, suicidal thoughts/behaviours and psychotic symptoms.

CONCLUSION

Most AEs during treatment with drugs for ADHD are manageable and most of the times it is not necessary to stop medication, so that patients with ADHD may continue to benefit from the effectiveness of pharmacological treatment.

Abstract P1-09-05: The RAZOR trial: a phase II prevention trial of screening plus goserilin and raloxifene versus screening alone in pre-menopausal women at increased risk of breast cancer

Background: Observational studies indicate that oophorectomy at about age 40 reduces breast cancer risk by approximately a half in high risk women. Widespread use of risk reducing oophorectomy is unlikely to be acceptable to these women. We explored the feasibility of giving goserelin to produce reversible ovarian suppression together with raloxifene to maintain bone mineral density (BMD).

Objectives: The primary study objective was adherence to treatment. Secondary objectives were uptake of randomisation, side effects/quality of life and measures of effect on bone and in serum.

Methods: Recruitment was from 3 UK Family History Clinics. Consenting women at ≥ 1 in 3 lifetime risk of breast cancer were randomised to control or monthly subcutaneous goserelin 3.6 mg and raloxifene 60 mg/d orally for two years. Questionnaires (Endocrine Symptom Checklist, Trait & State Anxiety, Sexual Activity & Cancer Worry) measuring toxicity/quality of life were administered by nurses. Dual energy X-ray absorptiometry (DXA) BMD measurements were performed in the treatment arm annually. Lipids and collagen breakdown products were measured by standard methods.

Results: 75 of 511 (14.7%) women approached agreed to randomisation (38 to treatment and 37 to control). The major reason for non-entry was fear of side effects (85%). Median age was 37 and 35 years, for the experimental (A) and control arm (B), respectively. Median follow up is 8.8 years. 20/38 in arm A and 27/37 of controls completed the 24 m study. 18/38 women in arm A withdrew (13 [34%] because of side effects) and 10/37 in arm B for various reasons including the desire for risk reducing surgery (n = 4). No significant differences were seen in the Endocrine Symptom Sub-scale, State or Trait anxiety or Cancer Worry. However, Hot flushes, night and cold sweats (together p &lt;0.005), vaginal dryness (p = 0.006); loss of interest in sex, dyspareunia and reduced sexual pleasure (together p &lt; 0.005) were significantly more in arm A. Despite this, 11 of 23 women in arm A when asked would have been happy to complete a potential five years of treatment. BMD declined by 3–7% and Ctx significantly increased (p &lt; 0.005 each) but both returned to baseline by year 3. Lipids were unchanged. 4 women later developed breast cancer in arm B and 2 in arm A.

Conclusions: Uptake and adherence to treatment was relatively low in this group of women at high risk. The major reason for low uptake was fear of side effects and these were the major reason for drop out from treatment. Raloxifene did not maintain BMD. This approach to breast cancer prevention induced significant symptoms and bone loss, thus methods to ameliorate these need to be developed if ovarian suppression is to play a role in breast cancer prevention.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-09-05.

Prevention of breast cancer in the context of a national breast screening programme

Breast cancer is not only increasing in the west but also particularly rapidly in eastern countries where traditionally the incidence has been low. The rise in incidence is mainly related to changes in reproductive patterns and lifestyle. These trends could potentially be reversed by defining women at greatest risk and offering appropriate preventive measures. A model for this approach was the establishment of Family History Clinics (FHCs), which have resulted in improved survival in younger women at high risk. New predictive models of risk that include reproductive and lifestyle factors, mammographic density and measurement of risk-associated single nucleotide polymorphisms (SNPs) may give more precise information concerning risk and enable better targeting for mammographic screening programmes and of preventive measures. Endocrine prevention using anti-oestrogens and aromatase inhibitors is effective, and observational studies suggest lifestyle modification may also be effective. However, referral to FHCs is opportunistic and predominantly includes younger women. A better approach for identifying older women at risk may be to use national breast screening programmes. Here were described pilot studies to assess whether the routine assessment of breast cancer risk is feasible within a population-based screening programme, whether the feedback and advice on risk-reducing interventions would be welcomed and taken up, and to consider whether the screening interval should be modified according to breast cancer risk.

The hierarchical factor model of ADHD: invariant across age and national groupings?

OBJECTIVE

To examine the factor structure of attention-deficit/hyperactivity disorder (ADHD) in a clinical sample of 1,373 children and adolescents with ADHD and their 1,772 unselected siblings recruited from different countries across a large age range. Hierarchical and correlated factor analytic models were compared separately in the ADHD and sibling samples, across three different instruments and across parent and teacher informants. Specific consideration was given to factorial invariance analyses across different ages and different countries in the ADHD sample.

METHOD

A sample of children and adolescents between 5 and 17 years of age with ADHD and their unselected siblings was assessed. Participants were recruited from seven European countries and Israel. ADHD symptom data came from a clinical interview with parents Parental Account of Childhood Symptoms and questionnaires from parents and teachers (Conners Parent and Teacher).

RESULTS

A hierarchical general factor model with two specific factors best represented the structure of ADHD in both the ADHD and unselected sibling groups, and across informants and instruments. The model was robust and invariant with regard to age differences in the ADHD sample. The model was not strongly invariant across different national groups in the ADHD sample, likely reflecting severity differences across the different centers and not any substantial difference in the clinical presentation of ADHD.

CONCLUSIONS

The results replicate previous studies of a model with a unitary ADHD component and separable specific traits of inattention and hyperactivity/impulsivity. The unique contribution of this study was finding support for this model across a large developmental and multinational/multicultural sample and its invariance across ages.

Neuropsychological intra-individual variability explains unique genetic variance of ADHD and shows suggestive linkage to chromosomes 12, 13, and 17

Attention-deficit/hyperactivity disorder (ADHD) is a highly heritable neuropsychiatric disorder that is usually accompanied by neuropsychological impairments. The use of heritable, psychometrically robust traits that show association with the disorder of interest can increase the power of gene-finding studies. Due to the robust association of intra-individual variability with ADHD on a phenotypic and genetic level, intra-individual variability is a prime candidate for such an attempt. We aimed to combine intra-individual variability measures across tasks into one more heritable measure, to examine the relatedness to other cognitive factors, and to explore the genetic underpinnings through quantitative trait linkage analysis. Intra-individual variability measures from seven tasks were available for 238 ADHD families (350 ADHD-affected and 195 non-affected children) and 147 control families (271 children). Intra-individual variability measures from seven different tasks shared common variance and could be used to construct an aggregated measure. This aggregated measure was largely independent from other cognitive factors related to ADHD and showed suggestive linkage to chromosomes 12q24.3 (LOD = 2.93), 13q22.2 (LOD = 2.36), and 17p13.3 (LOD = 2.00). A common intra-individual variability construct can be extracted from very diverse neuropsychological tasks; this construct taps into unique genetic aspects of ADHD and may relate to loci conferring risk for ADHD (12q24.3 and 17p13.3) and possibly autism (12q24.3). Given that joining of data across sites boosts the power for genetic analyses, our findings are promising in showing that intra-individual variability measures are viable candidates for across site analyses where different tasks have been used.

Genome-wide association study of motor coordination problems in ADHD identifies genes for brain and muscle function

OBJECTIVES

Motor coordination problems are frequent in children with attention deficit/hyperactivity disorder (ADHD). We performed a genome-wide association study to identify genes contributing to motor coordination problems, hypothesizing that the presence of such problems in children with ADHD may identify a sample of reduced genetic heterogeneity.

METHODS

Children with ADHD from the International Multicentre ADHD Genetic (IMAGE) study were evaluated with the Parental Account of Children's Symptoms. Genetic association testing was performed in PLINK on 890 probands with genome-wide genotyping data. Bioinformatics enrichment-analysis was performed on highly ranked findings. Further characterization of the findings was conducted in 313 Dutch IMAGE children using the Developmental Coordination Disorder Questionnaire (DCD-Q).

RESULTS

Although none of the findings reached genome-wide significance, bioinformatics analysis of the top-ranked findings revealed enrichment of genes for motor neuropathy and amyotrophic lateral sclerosis. Genes involved in neurite outgrowth and muscle function were also enriched. Among the highest ranked genes were MAP2K5, involved in restless legs syndrome, and CHD6, causing motor coordination problems in mice. Further characterization of these findings using DCD-Q subscales found nominal association for 15 SNPs.

CONCLUSIONS

Our findings provide clues about the aetiology of motor coordination problems, but replication studies in independent samples are necessary.

Genome-wide analysis of copy number variants in attention deficit hyperactivity disorder: the role of rare variants and duplications at 15q13.3

OBJECTIVE

Attention deficit hyperactivity disorder (ADHD) is a common, highly heritable psychiatric disorder. Because of its multifactorial etiology, however, identifying the genes involved has been difficult. The authors followed up on recent findings suggesting that rare copy number variants (CNVs) may be important for ADHD etiology.

METHOD

The authors performed a genome-wide analysis of large, rare CNVs (<1% population frequency) in children with ADHD (N=896) and comparison subjects (N=2,455) from the IMAGE II Consortium.

RESULTS

The authors observed 1,562 individually rare CNVs >100 kb in size, which segregated into 912 independent loci. Overall, the rate of rare CNVs >100 kb was 1.15 times higher in ADHD case subjects relative to comparison subjects, with duplications spanning known genes showing a 1.2-fold enrichment. In accordance with a previous study, rare CNVs >500 kb showed the greatest enrichment (1.28-fold). CNVs identified in ADHD case subjects were significantly enriched for loci implicated in autism and in schizophrenia. Duplications spanning the CHRNA7 gene at chromosome 15q13.3 were associated with ADHD in single-locus analysis. This finding was consistently replicated in an additional 2,242 ADHD case subjects and 8,552 comparison subjects from four independent cohorts from the United Kingdom, the United States, and Canada. Presence of the duplication at 15q13.3 appeared to be associated with comorbid conduct disorder.

CONCLUSIONS

These findings support the enrichment of large, rare CNVs in ADHD and implicate duplications at 15q13.3 as a novel risk factor for ADHD. With a frequency of 0.6% in the populations investigated and a relatively large effect size (odds ratio=2.22, 95% confidence interval=1.5–3.6), this locus could be an important contributor to ADHD etiology.

P4-11-07: Feasibility and Acceptability of Offering Breast Cancer Risk Estimation in the Context of the UK National Health Service Breast Cancer Screening Programme: A New Paradigm for Cancer Prevention

Background: Currently there are no real attempts internationally to tailor breast screening programmes to individual risk Methods: We have assessed the feasibility of collecting breast cancer risk information during routine mammographic screening in the National Health Service Breast Screening Programme (NHSBSP) in England, in order to consider, ultimately, adapting the screening interval to risk of breast cancer and introducing preventive strategies in women at high risk. The study Predicting Risk Of Cancer At Screening (PROCAS) aims to recruit 60,000 women over 3 years. Results: 26,000 women (June 8th 2011) have so far given consent to join the study. Thirty six percent of the first 20,000 women in nineteen screening sites in Manchester consented to enter the study and completed a risk factor questionnaire. The median 10 year breast cancer risk was 2.65%, with 926 (9.26%) of the first 10,000 women having a 10 year risk of ≥5% and 92 (0.92%) having a 10 year risk of ≥8% (Tyrer-Cuzick), IQR:1.35. 832 (8.32%) women had a mammographic density of 60% or greater (Visual Analogue Scale). We collected saliva samples from 1019 women for genetic analysis and will extend this to 18% of participants. Of those who agreed to participate in the study, 94% indicated that they wished to know their breast cancer risk. Women with a 10-year risk of ≥8%, and women with a 10-year risk of ≥5% and mammographic density ≥60% were invited to attend or be telephoned to be counselled. To date 138 have accepted with 135, so far, having received risk counselling. Nineteen percent of the high-risk women identified subsequently decided to enter a randomised breast cancer prevention study with either a dietary or drug intervention (IBIS2, anastrazole vs placebo). Results from the first 1,000 women who provided DNA samples suggest that the risk information from the 18 validated SNPS may enhance existing risk models. Conclusion: This study demonstrates that it is feasible to determine individual breast cancer risk and offer women appropriate risk-reducing interventions within the context of a population-based mammographic screening programme.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-11-07.

Genome-wide copy number variation study associates metabotropic glutamate receptor gene networks with attention deficit hyperactivity disorder

Attention deficit hyperactivity disorder (ADHD) is a common, heritable neuropsychiatric disorder of unknown etiology. We performed a whole-genome copy number variation (CNV) study on 1,013 cases with ADHD and 4,105 healthy children of European ancestry using 550,000 SNPs. We evaluated statistically significant findings in multiple independent cohorts, with a total of 2,493 cases with ADHD and 9,222 controls of European ancestry, using matched platforms. CNVs affecting metabotropic glutamate receptor genes were enriched across all cohorts (P = 2.1 × 10(-9)). We saw GRM5 (encoding glutamate receptor, metabotropic 5) deletions in ten cases and one control (P = 1.36 × 10(-6)). We saw GRM7 deletions in six cases, and we saw GRM8 deletions in eight cases and no controls. GRM1 was duplicated in eight cases. We experimentally validated the observed variants using quantitative RT-PCR. A gene network analysis showed that genes interacting with the genes in the GRM family are enriched for CNVs in ∼10% of the cases (P = 4.38 × 10(-10)) after correction for occurrence in the controls. We identified rare recurrent CNVs affecting glutamatergic neurotransmission genes that were overrepresented in multiple ADHD cohorts.

A functional variant of the serotonin transporter gene (SLC6A4) moderates impulsive choice in attention-deficit/hyperactivity disorder boys and siblings

BACKGROUND

Impulsive drive for immediate reward (IDIR) and delay aversion are dissociable elements of the preference for immediate over delayed rewards seen in attention-deficit/hyperactivity disorder (ADHD). We hypothesized that IDIR would be associated with dopamine regulating genes and delay aversion would be associated with serotonin-regulating genes.

METHODS

Impulsive drive for immediate reward and delay aversion were measured in 459 male children and adolescents (328 ADHD and 131 unaffected siblings) with a laboratory choice task. The sample was genotyped for the 5HTT (SLC6A4) promoter serotonin-transporter-linked polymorphic region polymorphism and a DAT1 (SLC6A3) 40-base pair variable number tandem repeat located in the 3'-untranslated region of the gene.

RESULTS

There was no effect of dopamine transporter (DAT)1 on IDIR. As predicted, serotonin-transporter-linked polymorphic region s-allele carriers were more delay averse. This effect was driven by the s/l genotype in the ADHD group. These results were not altered by taking account of the rs25531 A/G single nucleotide polymorphism and were independent of age, IQ, and oppositional defiant disorder symptoms.

CONCLUSIONS

The results support the genetic distinctiveness of IDIR and delay aversion in ADHD and implicate serotonin function in delay aversion. Possible explanations of the heterosis effect in the ADHD cases are presented.

The ATXN1 and TRIM31 genes are related to intelligence in an ADHD background: evidence from a large collaborative study totaling 4,963 subjects

Intelligence is a highly heritable trait for which it has proven difficult to identify the actual genes. In the past decade, five whole-genome linkage scans have suggested genomic regions important to human intelligence; however, so far none of the responsible genes or variants in those regions have been identified. Apart from these regions, a handful of candidate genes have been identified, although most of these are in need of replication. The recent growth in publicly available data sets that contain both whole genome association data and a wealth of phenotypic data, serves as an excellent resource for fine mapping and candidate gene replication. We used the publicly available data of 947 families participating in the International Multi-Centre ADHD Genetics (IMAGE) study to conduct an in silico fine mapping study of previously associated genomic locations, and to attempt replication of previously reported candidate genes for intelligence. Although this sample was ascertained for attention deficit/hyperactivity disorder (ADHD), intelligence quotient (IQ) scores were distributed normally. We tested 667 single nucleotide polymorphisms (SNPs) within 15 previously reported candidate genes for intelligence and 29451 SNPs in five genomic loci previously identified through whole genome linkage and association analyses. Significant SNPs were tested in four independent samples (4,357 subjects), one ascertained for ADHD, and three population-based samples. Associations between intelligence and SNPs in the ATXN1 and TRIM31 genes and in three genomic locations showed replicated association, but only in the samples ascertained for ADHD, suggesting that these genetic variants become particularly relevant to IQ on the background of a psychiatric disorder.

European guidelines on managing adverse effects of medication for ADHD

The safety of ADHD medications is not fully known. Concerns have arisen about both a lack of contemporary-standard information about medications first licensed several decades ago, and signals of possible harm arising from more recently developed medications. These relate to both relatively minor adverse effects and extremely serious issues such as sudden cardiac death and suicidality. A guidelines group of the European Network for Hyperkinetic Disorders (EUNETHYDIS) has therefore reviewed the literature, recruited renowned clinical subspecialists and consulted as a group to examine these concerns. Some of the effects examined appeared to be minimal in impact or difficult to distinguish from risk to untreated populations. However, several areas require further study to allow a more precise understanding of these risks.

Predictability of oppositional defiant disorder and symptom dimensions in children and adolescents with ADHD combined type

BACKGROUND

Oppositional defiant disorder (ODD) is frequently co-occurring with attention deficit hyperactivity disorder (ADHD) in children and adolescents. Because ODD is a precursor of later conduct disorder (CD) and affective disorders, early diagnostic identification is warranted. Furthermore, the predictability of three recently confirmed ODD dimensions (ODD-irritable, ODD-headstrong and ODD-hurtful) may assist clinical decision making.

METHOD

Receiver-operating characteristic (ROC) analysis was used in order to test the diagnostic accuracy of the Conners' Parent Rating Scale revised (CPRS-R) and the parent version of the Strength and Difficulties Questionnaire (PSDQ) in the prediction of ODD in a transnational sample of 1093 subjects aged 5-17 years from the International Multicentre ADHD Genetics study. In a second step, the prediction of three ODD dimensions by the same parent rating scales was assessed by backward linear regression analyses.

RESULTS

ROC analyses showed adequate diagnostic accuracy of the CPRS-R and the PSDQ in predicting ODD in this ADHD sample. Furthermore, the three-dimensional structure of ODD was confirmed by confirmatory factor analysis and the CPRS-R emotional lability scale significantly predicted the ODD irritable dimension.

CONCLUSIONS

The PSDQ and the CPRS-R are both suitable screening instruments in the identification of ODD. The emotional lability scale of the CPRS-R is an adequate predictor of irritability in youth referred for ADHD.

Case-control genome-wide association study of attention-deficit/hyperactivity disorder

OBJECTIVE

Although twin and family studies have shown attention-deficit/hyperactivity disorder (ADHD) to be highly heritable, genetic variants influencing the trait at a genome-wide significant level have yet to be identified. Thus additional genomewide association studies (GWAS) are needed.

METHOD

We used case-control analyses of 896 cases with DSM-IV ADHD genotyped using the Affymetrix 5.0 array and 2,455 repository controls screened for psychotic and bipolar symptoms genotyped using Affymetrix 6.0 arrays. A consensus SNP set was imputed using BEAGLE 3.0, resulting in an analysis dataset of 1,033,244 SNPs. Data were analyzed using a generalized linear model.

RESULTS

No genome-wide significant associations were found. The most significant results implicated the following genes: PRKG1, FLNC, TCERG1L, PPM1H, NXPH1, PPM1H, CDH13, HK1, and HKDC1.

CONCLUSIONS

The current analyses are a useful addition to the present literature and will make a valuable contribution to future meta-analyses. The candidate gene findings are consistent with a prior meta-analysis in suggesting that the effects of ADHD risk variants must, individually, be very small and/or include multiple rare alleles.

Emotional lability in children and adolescents with attention deficit/hyperactivity disorder (ADHD): clinical correlates and familial prevalence

BACKGROUND

The goal of this study was to investigate the occurrence, severity and clinical correlates of emotional lability (EL) in children with attention deficit/hyperactivity disorder (ADHD), and to examine factors contributing to EL and familiality of EL in youth with ADHD.

METHODS

One thousand, one hundred and eighty-six children with ADHD combined type and 1827 siblings (aged 6-18 years) were assessed for symptoms of EL, ADHD, associated psychopathology and comorbid psychiatric disorders with a structured diagnostic interview (PACS) as well as parent and teacher ratings of psychopathology (SDQ; CPRS-R:L; CTRS-R:L). Analyses of variance, regression analyses, chi(2)-tests or loglinear models were applied.

RESULTS

Mean age and gender-standardized ratings of EL in children with ADHD were >1.5 SD above the mean in normative samples. Severe EL (>75th percentile) was associated with more severe ADHD core symptoms, primarily hyperactive-impulsive symptoms, and more comorbid oppositional defiant, affective and substance use disorders. Age, hyperactive-impulsive, oppositional, and emotional symptoms accounted for 30% of EL variance; hyperactive-impulsive symptoms did not account for EL variance when coexisting oppositional and emotional problems were taken into account, but oppositional symptoms explained 12% of EL variance specifically. Severity of EL in probands increased the severity of EL in siblings, but not the prevalence rates of ADHD or ODD. EL and ADHD does not co-segregate within families.

CONCLUSION

EL is a frequent clinical problem in children with ADHD. It is associated with increased severity of ADHD core symptoms, particularly hyperactivity-impulsivity, and more symptoms of comorbid psychopathology, primarily symptoms of oppositional defiant disorder (ODD), but also affective symptoms, and substance abuse. EL in ADHD seems to be more closely related to ODD than to ADHD core symptoms, and is only partly explainable by the severity of ADHD core symptoms and associated psychopathology. Although EL symptoms are transmitted within families, EL in children with ADHD does not increase the risk of ADHD and ODD in their siblings.

The quality of life of children with attention deficit/hyperactivity disorder: a systematic review

Quality of life (QoL) describes an individual's subjective perception of their position in life as evidenced by their physical, psychological, and social functioning. QoL has become an increasingly important measure of outcome in child mental health clinical work and research. Here we provide a systematic review of QoL studies in children and young people with attention deficit hyperactivity disorder (ADHD) and address three main questions. (1) What is the impact of ADHD on QoL? (2) What are the relationships between ADHD symptoms, functional impairment and the mediators and moderators of QoL in ADHD? (3) Does the treatment of ADHD impact on QoL? Databases were systematically searched to identify research studies describing QoL in ADHD. Thirty six relevant articles were identified. Robust negative effects on QoL are reported by the parents of children with ADHD across a broad range of psycho-social, achievement and self evaluation domains. Children with ADHD rate their own QoL less negatively than their parents and do not always seeing themselves as functioning less well than healthy controls. ADHD has a comparable overall impact on QoL compared to other mental health conditions and severe physical disorders. Increased symptom level and impairment predicts poorer QoL. The presence of comorbid conditions or psychosocial stressors helps explain these effects. There is emerging evidence that QoL improves with effective treatment. In conclusion, ADHD seriously compromises QoL especially when seen from a parents' perspective. QoL outcomes should be included as a matter of course in future treatment studies.

ADHD and DAT1: further evidence of paternal over-transmission of risk alleles and haplotype

We [Hawi et al. (2005); Am J Hum Genet 77:958-965] reported paternal over-transmission of risk alleles in some ADHD-associated genes. This was particularly clear in the case of the DAT1 3'-UTR VNTR. In the current investigation, we analyzed three new sample comprising of 1,248 ADHD nuclear families to examine the allelic over-transmission of DAT1 in ADHD. The IMAGE sample, the largest of the three-replication samples, provides strong support for a parent of origin effect for allele 6 and the 10 repeat allele (intron 8 and 3'-UTR VNTR, respectively) of DAT1. In addition, a similar pattern of over-transmission of paternal risk haplotypes (constructed from the above alleles) was also observed. Some support is also derived from the two smaller samples although neither is independently significant. Although the mechanism driving the paternal over-transmission of the DAT risk alleles is not known, these finding provide further support for this phenomenon.

Dopamine and serotonin transporter genotypes moderate sensitivity to maternal expressed emotion: the case of conduct and emotional problems in attention deficit/hyperactivity disorder

BACKGROUND

Mothers' positive emotions expressed about their children with attention deficit/hyperactivity disorder (ADHD) are associated with a reduced likelihood of comorbid conduct problems (CP). We examined whether this association with CP, and one with emotional problems (EMO), is moderated by variants within three genes, previously reported to be associated with ADHD and to moderate the impact of environmental risks on conduct and/or emotional problems; the dopamine transporter gene (SLC6A3/DAT1), the dopamine D4 receptor gene (DRD4) and the serotonin transporter gene (SLC6A4/5HTT).

METHODS

Seven hundred and twenty-eight males between the ages of 5 and 17 with a DSM-IV research diagnosis of combined type ADHD were included in these analyses. Parents and teachers rated children's conduct and emotional problems. Positive maternal expressed emotion (PMEE) was coded by independent observers on comments made during a clinical assessment with the mother based on current or recent medication-free periods.

RESULTS

Sensitivity to the effects of PMEE on CP was moderated by variants of the DAT1 and 5HTT genes. Only children who did not carry the DAT1 10R/10R or the 5HTT l/l genotypes showed altered levels of CP when exposed to PMEE. The effect was most marked where the child with ADHD had both these genotypes. For EMO, sensitivity to PMEE was found only with those who carried the DAT1 9R/9R. There was no effect of DRD4 on CP or EMO.

CONCLUSION

The gene-environment interactions observed suggested that genetic make-up can alter the degree of sensitivity an ADHD patients has to their family environment. Further research should focus on distinguishing general sensitivity genotypes from those conferring risk or protective qualities.

Autism symptoms in Attention-Deficit/Hyperactivity Disorder: a familial trait which correlates with conduct, oppositional defiant, language and motor disorders

It is hypothesised that autism symptoms are present in Attention-Deficit/Hyperactivity Disorder (ADHD), are familial and index subtypes of ADHD. Autism symptoms were compared in 821 ADHD probands, 1050 siblings and 149 controls. Shared familiality of autism symptoms and ADHD was calculated using DeFries-Fulker analysis. Autism symptoms were higher in probands than siblings or controls, and higher in male siblings than male controls. Autism symptoms were familial, partly shared with familiality of ADHD in males. Latent class analysis using SCQ-score yielded five classes; Class 1(31%) had few autism symptoms and low comorbidity; Classes 2-4 were intermediate; Class 5(7%) had high autism symptoms and comorbidity. Thus autism symptoms in ADHD represent a familial trait associated with increased neurodevelopmental and oppositional/conduct disorders.

Conduct disorder and ADHD: evaluation of conduct problems as a categorical and quantitative trait in the international multicentre ADHD genetics study

Attention-deficit/hyperactivity disorder (ADHD) is typically characterized by inattention, excessive motor activity, impulsivity, and distractibility. Individuals with ADHD have significant impairment in family and peer relations, academic functioning, and show high co-morbidity with a wide range of psychiatric disorders including oppositional defiant disorder (ODD), conduct disorder (CD), anxiety disorder, depression, substance abuse, and pervasive developmental disorder (PDD). Family studies suggest that ADHD + CD represents a specific subtype of the ADHD disorder with familial risk factors only partly overlapping with those of ADHD alone. We performed a hypothesis-free analysis of the GAIN-ADHD sample to identify markers and genes important in the development of conduct problems in a European cohort of individuals with ADHD. Using the Family-Based Association Test (FBAT) package we examined three measures of conduct problems in 1,043,963 autosomal markers. This study is part of a series of exploratory analyses to identify candidate genes that may be important in ADHD and ADHD-related traits, such as conduct problems. We did not find genome-wide statistical significance (P < 5 x 10(-7)) for any of the tested markers and the three conduct problem traits. Fifty-four markers reached strong GWA signals (P < 10(-5)). We discuss these findings in the context of putative candidate genes and the implications of these findings in the understanding of the etiology of ADHD + CD. We aimed to achieve insight into the genetic etiology of a trait using a hypothesis-free study design and were able to identify a number of biologically interesting markers and genes for follow-up studies.

Meta-analysis of genome-wide linkage scans of attention deficit hyperactivity disorder

Genetic contribution to the development of attention deficit hyperactivity disorder (ADHD) is well established. Seven independent genome-wide linkage scans have been performed to map loci that increase the risk for ADHD. Although significant linkage signals were identified in some of the studies, there has been limited replications between the various independent datasets. The current study gathered the results from all seven of the ADHD linkage scans and performed a Genome Scan Meta Analysis (GSMA) to identify the genomic region with most consistent linkage evidence across the studies. Genome-wide significant linkage (P(SR) = 0.00034, P(OR) = 0.04) was identified on chromosome 16 between 64 and 83 Mb. In addition there are nine other genomic regions from the GSMA showing nominal or suggestive evidence of linkage. All these linkage results may be informative and focus the search for novel ADHD susceptibility genes.

Does parental expressed emotion moderate genetic effects in ADHD? An exploration using a genome wide association scan

Studies of gene x environment (G x E) interaction in ADHD have previously focused on known risk genes for ADHD and environmentally mediated biological risk. Here we use G x E analysis in the context of a genome-wide association scan to identify novel genes whose effects on ADHD symptoms and comorbid conduct disorder are moderated by high maternal expressed emotion (EE). SNPs (600,000) were genotyped in 958 ADHD proband-parent trios. After applying data cleaning procedures we examined 429,981 autosomal SNPs in 909 family trios. ADHD symptom severity and comorbid conduct disorder was measured using the Parental Account of Childhood Symptoms interview. Maternal criticism and warmth (i.e., EE) were coded by independent observers on comments made during the interview. No G x E interactions reached genome-wide significance. Nominal effects were found both with and without genetic main effects. For those with genetic main effects 36 uncorrected interaction P-values were <10(-5) implicating both novel genes as well as some previously supported candidates. These were found equally often for all of the interactions being investigated. The observed interactions in SLC1A1 and NRG3 SNPs represent reasonable candidate genes for further investigation given their previous association with several psychiatric illnesses. We find evidence for the role of EE in moderating the effects of genes on ADHD severity and comorbid conduct disorder, implicating both novel and established candidates. These findings need replicating in larger independent samples.