Childhood correlates and young adult outcomes of trajectories of emotional problems from childhood to adolescence

BACKGROUND

Emotional problems, especially anxiety, have become increasingly common in recent generations. Few population-based studies have examined trajectories of emotional problems from early childhood to late adolescence or investigated differences in psychiatric and functional outcomes.

METHODS

Using the Avon Longitudinal Study of Parents and Children (ALSPAC, n = 8286, 50.4% male), we modeled latent class growth trajectories of emotional problems, using the parent-reported Strength and Difficulties Questionnaire emotional scale (SDQ-E) on seven occasions (4-17 years). Psychiatric outcomes in young adulthood (21-25 years) were major depressive disorder (MDD), generalized anxiety disorder (GAD), and self-harm. Functional outcomes were exam attainment, educational/occupational status, and social relationship quality.

RESULTS

We identified four classes of emotional problems: low (67.0%), decreasing (18.4%), increasing (8.9%), and persistent (5.7%) problems. Compared to those in the low class, individuals with decreasing emotional problems were not at elevated risk of any poor adult outcome. Individuals in the increasing and persistent classes had a greater risk of adult MDD (RR: 1.59 95% CI 1.13-2.26 and RR: 2.25 95% CI 1.49-3.41) and self-harm (RR: 2.37 95% CI 1.91-2.94 and RR: 1.87 95% CI 1.41-2.48), and of impairment in functional domains. Childhood sleep difficulties, irritability, conduct and neurodevelopmental problems, and family adversity were associated with a persistent course of emotional problems.

CONCLUSIONS

Childhood emotional problems were common, but those whose symptoms improved over time were not at increased risk for adverse adult outcomes. In contrast, individuals with persistent or adolescent-increasing emotional problems had a higher risk of mental ill-health and social impairment in young adulthood which was especially pronounced for those with persistent emotional problems.

Disentangling nature from nurture in examining the interplay between parent-child relationships, ADHD, and early academic attainment

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) is highly heritable and is associated with lower educational attainment. ADHD is linked to family adversity, including hostile parenting. Questions remain regarding the role of genetic and environmental factors underlying processes through which ADHD symptoms develop and influence academic attainment.

METHOD

This study employed a parent-offspring adoption design (N = 345) to examine the interplay between genetic susceptibility to child attention problems (birth mother ADHD symptoms) and adoptive parent (mother and father) hostility on child lower academic outcomes, via child ADHD symptoms. Questionnaires assessed birth mother ADHD symptoms, adoptive parent (mother and father) hostility to child, early child impulsivity/activation, and child ADHD symptoms. The Woodcock-Johnson test was used to examine child reading and math aptitude.

RESULTS

Building on a previous study (Harold et al., 2013, Journal of Child Psychology and Psychiatry, 54(10), 1038-1046), heritable influences were found: birth mother ADHD symptoms predicted child impulsivity/activation. In turn, child impulsivity/activation (4.5 years) evoked maternal and paternal hostility, which was associated with children's ADHD continuity (6 years). Both maternal and paternal hostility (4.5 years) contributed to impairments in math but not reading (7 years), via impacts on ADHD symptoms (6 years).

CONCLUSION

Findings highlight the importance of early child behavior dysregulation evoking parent hostility in both mothers and fathers, with maternal and paternal hostility contributing to the continuation of ADHD symptoms and lower levels of later math ability. Early interventions may be important for the promotion of child math skills in those with ADHD symptoms, especially where children have high levels of early behavior dysregulation.

A risk calculator to predict adult attention-deficit/hyperactivity disorder: generation and external validation in three birth cohorts and one clinical sample

AIM

Few personalised medicine investigations have been conducted for mental health. We aimed to generate and validate a risk tool that predicts adult attention-deficit/hyperactivity disorder (ADHD).

METHODS

Using logistic regression models, we generated a risk tool in a representative population cohort (ALSPAC - UK, 5113 participants, followed from birth to age 17) using childhood clinical and sociodemographic data with internal validation. Predictors included sex, socioeconomic status, single-parent family, ADHD symptoms, comorbid disruptive disorders, childhood maltreatment, ADHD symptoms, depressive symptoms, mother's depression and intelligence quotient. The outcome was defined as a categorical diagnosis of ADHD in young adulthood without requiring age at onset criteria. We also tested Machine Learning approaches for developing the risk models: Random Forest, Stochastic Gradient Boosting and Artificial Neural Network. The risk tool was externally validated in the E-Risk cohort (UK, 2040 participants, birth to age 18), the 1993 Pelotas Birth Cohort (Brazil, 3911 participants, birth to age 18) and the MTA clinical sample (USA, 476 children with ADHD and 241 controls followed for 16 years from a minimum of 8 and a maximum of 26 years old).

RESULTS

The overall prevalence of adult ADHD ranged from 8.1 to 12% in the population-based samples, and was 28.6% in the clinical sample. The internal performance of the model in the generating sample was good, with an area under the curve (AUC) for predicting adult ADHD of 0.82 (95% confidence interval (CI) 0.79-0.83). Calibration plots showed good agreement between predicted and observed event frequencies from 0 to 60% probability. In the UK birth cohort test sample, the AUC was 0.75 (95% CI 0.71-0.78). In the Brazilian birth cohort test sample, the AUC was significantly lower -0.57 (95% CI 0.54-0.60). In the clinical trial test sample, the AUC was 0.76 (95% CI 0.73-0.80). The risk model did not predict adult anxiety or major depressive disorder. Machine Learning approaches did not outperform logistic regression models. An open-source and free risk calculator was generated for clinical use and is available online at https://ufrgs.br/prodah/adhd-calculator/.

CONCLUSIONS

The risk tool based on childhood characteristics specifically predicts adult ADHD in European and North-American population-based and clinical samples with comparable discrimination to commonly used clinical tools in internal medicine and higher than most previous attempts for mental and neurological disorders. However, its use in middle-income settings requires caution.

Adolescent and adult differences in major depression symptom profiles

BACKGROUND

Depression is the leading global cause of disability and often begins in adolescence. The genetic architecture and treatment response profiles for adults and adolescents differ even though identical criteria are used to diagnose depression across different age groups. There is no clear consensus on how these groups differ in their symptom profiles.

METHODS

Using data from a two-generation family study, we compared the presentation of DSM-IV depressive symptoms in adolescents and adults with MDD (Major Depressive Disorder). We also compared DSM-IV depressive symptom counts using latent class analysis.

RESULTS

Vegetative symptoms (appetite and weight change, loss of energy and insomnia) were more common in adolescent MDD than adult MDD. Anhedonia/loss of interest and concentration problems were more common in adults with MDD. When using latent class analysis to look at depressive symptoms, a vegetative symptom profile was also seen in adolescent depression only.

LIMITATIONS

Adults and adolescents were recruited in different ways. Adolescent cases were more likely to be first-onset while adult cases were recurrences. It was not possible to examine how recurrence affected adolescent depression symptom profiles.

CONCLUSION

Differences in how depression presents in adolescents and adults may be consistent with different pathophysiological mechanisms. For adolescents, we found that vegetative/physical disturbances were common (loss of energy, changes in weight, appetite and sleep changes). For adults, anhedonia/loss of interest and concentration difficulties were more common.

Testosterone therapy for sexual dysfunction in men with Type 2 diabetes: a systematic review and meta-analysis of randomized controlled trials

AIM

To evaluate the effectiveness of testosterone therapy on a range of sexual function domains in men with Type 2 diabetes.

METHOD

Electronic databases were searched for studies investigating the effect of testosterone therapy on sexual function in men with Type 2 diabetes. All randomized controlled trials were considered for inclusion if they compared the efficacy of testosterone therapy with that of placebo and reported sexual function outcomes. Statistical analysis was performed using a random-effects model, and heterogeneity was expressed using the I² statistic.

RESULTS

A total of 611 articles were screened. Six randomized control trials, in a total of 587 men with Type 2 diabetes, were eligible for inclusion. The pooled data suggested that testosterone therapy improves sexual desire (random-effects pooled effect size 0.314; 95% CI 0.082-0.546) and erectile function (random-effects pooled effect size 0.203; 95% CI 0.007-0.399) when compared with control groups. Testosterone therapy had no significant effect on constitutional symptoms or other sexual domains compared with control groups. No studies have investigated the incidence of prostate cancer, fertility and cardiovascular disease after testosterone therapy in men with Type 2 diabetes.

CONCLUSION

Testosterone therapy may moderately improve sexual desire and erectile function in men with Type 2 diabetes; however, available data are limited, and the long-term risks of testosterone therapy are not known in this specific patient group. We conclude that testosterone therapy is a potential treatment for men with Type 2 diabetes non-responsive to phosphodiesterase-5 inhibitors. Testosterone therapy could be considered for men with Type 2 diabetes when potential risks and benefits of therapy are carefully considered and other therapeutic options are unsuitable.

Investigating the genetic underpinnings of early-life irritability

Severe irritability is one of the commonest reasons prompting referral to mental health services. It is frequently seen in neurodevelopmental disorders that manifest early in development, especially attention-deficit/hyperactivity disorder (ADHD). However, irritability can also be conceptualized as a mood problem because of its links with anxiety/depressive disorders; notably DSM-5 currently classifies severe, childhood-onset irritability as a mood disorder. Investigations into the genetic nature of irritability are lacking although twin studies suggest it shares genetic risks with both ADHD and depression. We investigated the genetic underpinnings of irritability using a molecular genetic approach, testing the hypothesis that early irritability (in childhood/adolescence) is associated with genetic risk for ADHD, as indexed by polygenic risk scores (PRS). As a secondary aim we investigated associations between irritability and PRS for major depressive disorder (MDD). Three UK samples were utilized: two longitudinal population-based cohorts with irritability data from childhood (7 years) to adolescence (15-16 years), and one ADHD patient sample (6-18 years). Irritability was defined using parent reports. PRS were derived from large genome-wide association meta-analyses. We observed associations between ADHD PRS and early irritability in our clinical ADHD sample and one of the population samples. This suggests that early irritability traits share genetic risk with ADHD in the general population and are a marker of higher genetic loading in individuals with an ADHD diagnosis. Associations with MDD PRS were not observed. This suggests that early-onset irritability could be conceptualized as a neurodevelopmental difficulty, behaving more like disorders such as ADHD than mood disorders.

Explaining risk for suicidal ideation in adolescent offspring of mothers with depression

BACKGROUND

It is well-established that offspring of depressed mothers are at increased risk for suicidal ideation. However, pathways involved in the transmission of risk for suicidal ideation from depressed mothers to offspring are poorly understood. The aim of this study was to examine the contribution of potential mediators of this association, including maternal suicide attempt, offspring psychiatric disorder and the parent-child relationship.

METHOD

Data were utilized from a population-based birth cohort (ALSPAC). Three distinct classes of maternal depression symptoms across the first 11 years of the child's life had already been identified (minimal, moderate, chronic-severe). Offspring suicidal ideation was assessed at age 16 years. Data were analysed using structural equation modelling.

RESULTS

There was evidence for increased risk of suicidal ideation in offspring of mothers with chronic-severe depression symptoms compared to offspring of mothers with minimal symptoms (odds ratio 3.04, 95% confidence interval 2.19-4.21). The majority of this association was explained through maternal suicide attempt and offspring psychiatric disorder. There was also evidence for an independent indirect effect via the parent-child relationship in middle childhood. There was no longer evidence of a direct effect of maternal depression on offspring suicidal ideation after accounting for all three mediators. The pattern of results was similar when examining mechanisms for maternal moderate depression symptoms.

CONCLUSIONS

Findings highlight that suicide prevention efforts in offspring of depressed mothers should be particularly targeted at both offspring with a psychiatric disorder and offspring whose mothers have made a suicide attempt. Interventions aimed at improving the parent-child relationship may also be beneficial.

Acoustic reflectors are visible in the right heart during radiofrequency ablation of varicose veins

Objective

Cerebrovascular events have been noted after foam sclerotherapy for varicose veins. One hypothesis is migration of microemboli to the brain through a cardiac septal defect. The aim of this study was to identify whether acoustic reflectors are found in the right side of the heart during radiofrequency ablation of varicose veins, as neurological events are not reported during these procedures.

Methods

Transthoracic echocardiography was performed during local anaesthetic radiofrequency ablation (VNUS ClosureFast) of the great saphenous vein in 14 patients. An apical view was captured at the start of the procedure, during each cycle of heating and at 1 min post-treatment. Patients were monitored for 1 h. Video loops were read by an independent cardiologist. The presence of acoustic reflectors was classified as: 0 = absent, 1 = occasional, 2 = stream, 3 = complete opacification.

Results

Loops were of diagnostic quality in 11/14 (79%) patients. After the second cycle of heating, acoustic reflectors moving through the right heart were seen in 5/11 (45%) patients. These were classified as grade 1 in four patients and grade 2 in one patient. No acoustic reflectors were seen in the left heart. No neurological symptoms were reported.

Conclusion

Acoustic reflectors in the right heart are a common finding during radiofrequency ablation of varicose veins. Considering the prevalence of cardiac septal defects (17%), more neurological events would be expected if these particles were indeed responsible for these events. Further work is required to elicit the mechanisms underlying neurological complications following sclerotherapy.

Day-case minimally invasive excision of a giant mediastinal parathyroid adenoma

Inferior parathyroid adenomas in the mediastinum can be a troublesome cause for hypercalcaemia, requiring a full collar incision or, occasionally, a sternotomy. We report a case of a giant parathyroid adenoma in a 61-year-old woman on warfarin, which we excised via a minimally invasive transcervical approach after radiological localisation. The procedure was performed as a day case and, at six weeks, the patient had recovered fully with biochemical resolution of hypercalcaemia. This case demonstrates that focused transcervical excision of giant parathyroid adenomas is a viable option and should be considered prior to neck exploration or sternotomy.

Impact of risk scoring on decision-making in symptomatic moderate carotid atherosclerosis

Background

Benefit from carotid endarterectomy (CEA) in symptomatic moderate (50–69 per cent) carotid stenosis remains marginal. The Fourth National Clinical Guideline for Stroke recommends use of the risk score from the European Carotid Surgery Trial (ECST) to aid decision-making in symptomatic carotid disease. It is not known whether clinicians are, in fact, influenced by it.

Methods

Using the ECST risk prediction model, three scenarios of patients with a low (less than 10 per cent), moderate (20–25 per cent) and high (40–45 per cent) 5-year risk of stroke were devised and validated. Invitations to complete an online survey were sent by e-mail to vascular surgeons and stroke physicians, with responses gathered. The questionnaire was then repeated with the addition of the ECST risk score.

Results

Two hundred and one completed surveys were analysed (21·5 per cent response rate): 107 by stroke physicians and 94 by vascular surgeons. The high-risk scenario after the introduction of the ECST risk score showed an increased use of CEA (66·7 versus 80·1 per cent; P = 0·009). The low-risk scenario after risk score analysis demonstrated a swing towards best medical therapy (23·4 versus 57·2 per cent; P < 0·001). CEA was preferred in the moderate-risk scenario and this was not altered significantly by introduction of the risk score (71·6 versus 75·6 per cent; P = 0·609). Vascular surgeons exhibited a preference towards CEA compared with stroke physicians in both low- and moderate-risk scenarios (P < 0·001 and P = 0·003 respectively).

Conclusion

The addition of a risk score appeared to influence clinicians in their decision-making towards CEA in high-risk patients and towards best medical therapy in low-risk patients.

The European burden of primary varicose veins

BACKGROUND

The treatment of varicose veins has been demonstrated to improve quality of life, alleviate symptoms of depression and treat the complications of venous disease. This study aims to show the studies which contain information regarding the prevalence and distribution of venous disease. Then using the population and prevalence data for venous disease, and considering the cost of treating varicose veins, this study aims to analyse the treatment of varicose veins and assess whether there is a disparity between European countries.

METHODS

Relevant papers regarding the prevalence or incidence of venous disease were identified through searches of PubMed (1966 to October 2010). The search terms 'prevalence OR incidence' AND 'varicose veins or venous disease' were used. Population data, prevalence data and the number of varicose vein procedures performed in each country was obtained for 2010.

RESULTS

Four studies were included. From calculated values comparing the predicted and actual number of patients requiring treatment for venous disease, the UK, Finland and Sweden are potentially not treating all patients with C2 disease. In contrast to this, all other European countries represented are treating more patients, suggesting that they may be treating additional patients. There was up to a four-fold difference in the numbers of procedures per million population that were performed for varicose veins in different European countries.

CONCLUSION

There is a marked disparity across Europe between the predicted number of patients with varicose veins requiring treatment and the actual care given. The factors influencing this need more detailed investigation.

'The risks of playing it safe': a prospective longitudinal study of response to reward in the adolescent offspring of depressed parents

BACKGROUND

Alterations in reward processing may represent an early vulnerability factor for the development of depressive disorder. Depression in adults is associated with reward hyposensitivity and diminished reward seeking may also be a feature of depression in children and adolescents. We examined the role of reward responding in predicting depressive symptoms, functional impairment and new-onset depressive disorder over time in the adolescent offspring of depressed parents. In addition, we examined group differences in reward responding between currently depressed adolescents, psychiatric and healthy controls, and also cross-sectional associations between reward responding and measures of positive social/environmental functioning. Method We conducted a 1-year longitudinal study of adolescents at familial risk for depression (n = 197; age range 10-18 years). Reward responding and self-reported social/environmental functioning were assessed at baseline. Clinical interviews determined diagnostic status at baseline and at follow-up. Reports of depressive symptoms and functional impairment were also obtained.

RESULTS

Low reward seeking predicted depressive symptoms and new-onset depressive disorder at the 1-year follow-up in individuals free from depressive disorder at baseline, independently of baseline depressive symptoms. Reduced reward seeking also predicted functional impairment. Adolescents with current depressive disorder were less reward seeking (i.e. bet less at favourable odds) than adolescents free from psychopathology and those with externalizing disorders. Reward seeking showed positive associations with social and environmental functioning (extra-curricular activities, humour, friendships) and was negatively associated with anhedonia. There were no group differences in impulsivity, decision making or psychomotor slowing.

CONCLUSIONS

Reward seeking predicts depression severity and onset in adolescents at elevated risk of depression. Adaptive reward responses may be amenable to change through modification of existing preventive psychological interventions.

Modelling the cost-effectiveness of carotid endarterectomy for asymptomatic stenosis5

Background

The aim of this study was to model the cost-effectiveness of carotid endarterectomy for asymptomatic stenosis versus medical therapy based on 10-year data from the Asymptomatic Carotid Surgery Trial (ACST).

Methods

This was a cost–utility analysis based on clinical effectiveness data from the ACST with UK-specific costs and stroke outcomes. A Markov model was used to calculate the incremental cost-effectiveness ratio (ICER, or cost per additional quality-of-life year) for a strategy of early endarterectomy versus medical therapy for the average patient and published subgroups. An exploratory analysis considered contemporary event rates.

Results

The ICER was £ 7584 per additional quality-adjusted life-year (QALY) for the average patient in the ACST. At thresholds of £ 20 000 and £ 30 000 there was a 74 and 84 per cent chance respectively of early endarterectomy being cost-effective. The ICER for men below 75 years of age was £ 3254, and that for men aged 75 years or above was £ 71 699. For women aged under 75 years endarterectomy was less costly and more effective than medical therapy; for women aged 75 years or more endarterectomy was less effective and more costly than medical therapy. At contemporary perioperative event rates of 2·7 per cent and background any-territory stroke rates of 1·6 per cent, early endarterectomy remained cost-effective.

Conclusion

In the ACST, early endarterectomy was predicted to be cost-effective in those below 75 years of age, using a threshold of £ 20 000 per QALY. If background any-territory stroke rates fell below 1 per cent per annum, early endarterectomy would cease to be cost-effective.

Systematic review of sonographic chronic cerebrospinal venous insufficiency findings in multiple sclerosis

OBJECTIVE

The sonographic findings of chronic cerebrospinal venous insufficiency (CCSVI) are used by some as selection criteria for venography. We performed a systematic review to establish the prevalence and strength of association between sonographic CCSVI and multiple sclerosis (MS).

METHOD

Two reviewers searched PubMed and EMBASE from 1948 to date using the keywords 'chronic cerebrospinal venous insufficiency' according to PRISMA guidelines.

RESULTS

Four cross-sectional studies met the criteria for inclusion. The prevalence of CCSVI ranged from 7% to 100% in MS patients and from 2% to 36% in healthy controls. Diagnostic odds ratios for MS varied between 2 and 26, 499 (I(2) = 94%). Sensitivities of CCSVI for MS varied between 7% and 100% (I(2) = 98%). Specificities varied between 64% and 100% (I(2) = 95%).

CONCLUSION

There is substantial variation in the strength of association between CCSVI and MS beyond that explained by demographic differences or sonographer training. Reliable evidence on which to base decisions requires sonographic consensus and assessment of the reproducibility of individual criteria between trained sonographers.

Internal jugular thrombosis post venoplasty for chronic cerebrospinal venous insufficiency

Chronic cerebrospinal venous insufficiency (CCSVI) is a hypothesis through which cerebral venous drainage abnormalities contribute towards the pathogenesis of multiple sclerosis. CCSVI venoplasty is already practised worldwide. We report the case of a 33-year-old lady with multiple sclerosis who underwent left internal jugular venoplasty resulting in iatrogenic jugular thrombosis requiring open thrombectomy for symptom relief. This occurred without insertion of a stent and while fully anticoagulated. Clinicians should be aware that endovenous treatment of CCSVI could cause paradoxical deterioration of cerebral venous drainage. Patients with complications post venoplasty are now presenting to geographically distant vascular units.

Familial transmission of depression and antisocial behavior symptoms: disentangling the contribution of inherited and environmental factors and testing the mediating role of parenting

BACKGROUND

Genetic and environmental influences on child psychopathology have been studied extensively through twin and adoption designs. We offer a novel methodology to examine genetic and environmental influences on the intergenerational transmission of psychopathology using a sample of parents and children conceived through in vitro fertilization (IVF).

METHOD

The sample included families with children born through IVF methods, who varied as to whether the child was genetically related or unrelated to the rearing mother and father (mother genetically related, n=434; mother genetically unrelated, n=127; father genetically related, n=403; father genetically unrelated, n=156). Using standardized questionnaires, mothers and fathers respectively reported on their own psychopathology (depression, aggression), their parenting behavior toward their child (warmth, hostility) and their child's psychopathology (depression, aggression). A cross-rater approach was used, where opposite parents reported on child symptoms (i.e. fathers reported on symptoms for the mother-child dyad, and vice versa).

RESULTS

For mother-child dyads, a direct association between mother depression and child depression was observed among genetically unrelated dyads, whereas a fully mediated path was observed among genetically related dyads through mother-to-child hostility and warmth. For father-child dyads, direct and mediated pathways were observed for genetically related father-child dyads. For aggression, the direct association between parent aggression and child aggression was fully mediated by parent-to-child hostility for both groups, indicating the role of parent-to-child hostility as a risk mechanism for transmission.

CONCLUSIONS

A differential pattern of genetic and environmental mediation underlying the intergenerational transmission of psychopathology was observed among genetically related and genetically unrelated father-child and mother-child dyads.

Steroid sulfatase is a potential modifier of cognition in attention deficit hyperactivity disorder

Deletions encompassing the X-linked STS gene (encoding steroid sulfatase) have been observed in subjects with neurodevelopmental disorders, including attention deficit hyperactivity disorder (ADHD). Recently, two single nucleotide polymorphisms (SNPs) within STS (rs12861247 and rs17268988) have been reported to be associated with ADHD risk and inattentive symptoms in ADHD, respectively. Using a UK sample of ADHD subjects (aged 5-18 years), we tested the hypothesis that rs12861247 is associated with ADHD risk using a case-control approach (comparing 327 ADHD cases with 358 male controls from the Wellcome Trust Case Control Consortium). Using a subset of males from the ADHD sample, we also examined whether variation within STS is associated with symptomatology/cognitive function in ADHD. We then tested whether SNPs associated with cognitive function in ADHD were also associated with cognitive function in healthy male subjects using a German sample (n = 143, aged 18-30 years), and whether STS was expressed in brain regions pertinent to ADHD pathology during development. We did not replicate the previously identified association with rs12861247. However, in ADHD males, variation at rs17268988 was associated with inattentive symptoms, while variation within STS was significantly associated with performance on three cognitive measures. Three SNPs associated with cognitive function in ADHD males were not associated with cognitive function in healthy males. STS was highly expressed in the developing cerebellar neuroepithelium, basal ganglia, thalamus, pituitary gland, hypothalamus and choroid plexus. These data suggest that genetic variants affecting STS expression and/or activity could influence the function of brain regions perturbed in ADHD.

Internal or external wall diameter for abdominal aortic aneurysm screening?

INTRODUCTION

The national abdominal aortic aneurysm (AAA) screening programme measures internal wall diameter; however, current UK intervention criteria use external wall diameter. Our aim was to determine the clinical significance of the difference between these two measurements.

PATIENTS AND METHODS

Fifty patients on an aneurysm surveillance programme were ultrasound scanned by two experienced vascular scientists, blinded to the other's results. Maximum anteroposterior internal wall and maximum anteroposterior external wall diameters were measured.

RESULTS

The median difference between internal and external diameter was 6 mm (IQR 6-7) for scientist 1 and 7 mm (IQR 5-8) for scientist 2. This was statistically significant (P < 0.0002). External wall diameter displayed less interobserver variability (3 mm vs 6 mm).

CONCLUSIONS

Screening measurements underestimate aneurysm size by 6 mm and display greater variability in comparison to external wall measurements. These findings should be understood to prevent a delay in the detection and treatment of AAAs.

The links between prenatal stress and offspring development and psychopathology: disentangling environmental and inherited influences

BACKGROUND

Exposure to prenatal stress is associated with later adverse health and adjustment outcomes. This is generally presumed to arise through early environmentally mediated programming effects on the foetus. However, associations could arise through factors that influence mothers' characteristics and behaviour during pregnancy which are inherited by offspring.

METHOD

A 'prenatal cross-fostering' design where pregnant mothers are related or unrelated to their child as a result of in vitro fertilization (IVF) was used to disentangle maternally inherited and environmental influences. If links between prenatal stress and offspring outcome are environmental, association should be observed in unrelated as well as related mother-child pairs. Offspring birth weight and gestational age as well as mental health were the outcomes assessed.

RESULTS

Associations between prenatal stress and offspring birth weight, gestational age and antisocial behaviour were seen in both related and unrelated mother-offspring pairs, consistent with there being environmental links. The association between prenatal stress and offspring anxiety in related and unrelated groups appeared to be due to current maternal anxiety/depression rather than prenatal stress. In contrast, the link between prenatal stress and offspring attention deficit hyperactivity disorder was only present in related mother-offspring pairs and therefore was attributable to inherited factors.

CONCLUSIONS

Genetically informative designs can be helpful in testing whether inherited factors contribute to the association between environmental risk factors and health outcomes. These results suggest that associations between prenatal stress and offspring outcomes could arise from inherited factors and post-natal environmental factors in addition to causal prenatal risk effects.

NK1 (TACR1) receptor gene 'knockout' mouse phenotype predicts genetic association with ADHD

Mice with functional genetic ablation of the Tacr1 (substance P-preferring receptor) gene (NK1R-/-) are hyperactive. Here, we investigated whether this is mimicked by NK1R antagonism and whether dopaminergic transmission is disrupted in brain regions that govern motor performance. The locomotor activity of NK1R-/- and wild-type mice was compared after treatment with an NK1R antagonist and/or psychostimulant (d-amphetamine or methylphenidate). The inactivation of NK1R (by gene mutation or receptor antagonism) induced hyperactivity in mice, which was prevented by both psychostimulants. Using in vivo microdialysis, we then compared the regulation of extracellular dopamine in the prefrontal cortex (PFC) and striatum in the two genotypes. A lack of functional NK1R reduced (>50%) spontaneous dopamine efflux in the prefrontal cortex and abolished the striatal dopamine response to d-amphetamine. These behavioural and neurochemical abnormalities in NK1R-/- mice, together with their atypical response to psychostimulants, echo attention deficit hyperactivity disorder (ADHD) in humans. These findings prompted genetic studies on the TACR1 gene (the human equivalent of NK1R) in ADHD patients in a case-control study of 450 ADHD patients and 600 screened supernormal controls. Four single-nucleotide polymorphisms (rs3771829, rs3771833, rs3771856, and rs1701137) at the TACR1 gene, previously known to be associated with bipolar disorder or alcoholism, were strongly associated with ADHD. In conclusion, our proposal that NK1R-/- mice offer a mouse model of ADHD was borne out by our human studies, which suggest that DNA sequence changes in and around the TACR1 gene increase susceptibility to this disorder.

Differential dopamine receptor D4 allele association with ADHD dependent of proband season of birth

Season of birth (SOB) has been associated with attention deficit hyperactivity disorder (ADHD) in two existing studies. One further study reported an interaction between SOB and genotypes of the dopamine D4 receptor (DRD4) gene. It is important that these findings are further investigated to confirm or refute the findings. In this study, we investigated the SOB association with ADHD in four independent samples collected for molecular genetic studies of ADHD and found a small but significant increase in summer births compared to a large population control dataset. We also observed a significant association with the 7-repeat allele of the DRD4 gene variable number tandem repeat polymorphism in exon three with probands born in the winter season, with no significant differential transmission of this allele between summer and winter seasons. Preferential transmission of the 2-repeat allele to ADHD probands occurred in those who were born during the summer season, but did not surpass significance for association, even though the difference in transmission between the two seasons was nominally significant. However, following adjustment for multiple testing of alleles none of the SOB effects remained significant. We conclude that the DRD4 7-repeat allele is associated with ADHD but there is no association or interaction with SOB for increased risk for ADHD. Our findings suggest that we can refute a possible effect of SOB for ADHD.

Testing for gene x environment interaction effects in attention deficit hyperactivity disorder and associated antisocial behavior

Gene x environment (G x E) interactions are increasingly thought to have substantial influence on the aetiology and clinical manifestations of complex disorders. In ADHD, although main effects of specific genetic variants and pre- or peri-natal variables have been reported and replicated using pooled analyses, few studies have looked at possible interactions. In a clinical sample of 266 children with ADHD, we tested for interaction between gene variants (in DRD4, DAT1, DRD5, and 5HTT) found to be associated with ADHD in pooled analyses and maternal smoking, alcohol use during pregnancy and birth weight. First, G x E effects on a diagnosis of ADHD were tested using conditional logistic regression analyses. Second, possible modifying effects of G x E on symptoms of associated conduct disorder and oppositional defiant disorder (ODD) were investigated using linear regression analysis. The sample size associated with each of the analyses differed as not each variant had been genotyped for each individual. No effects of G x E on ADHD diagnosis were observed. The results suggest that lower birth weight and maternal smoking during pregnancy may interact with DRD5 and DAT1 (birth weight only) in influencing associated antisocial behavior symptoms (ODD and conduct disorder). These preliminary findings showed no evidence of interaction between previously implicated variants in ADHD and specific environmental risk factors, on diagnosis of the disorder. There may be evidence of G x E on associated antisocial behavior in ADHD, but further investigation is needed.

The impact of gestational stress and prenatal growth on emotional problems in offspring: a review

OBJECTIVE

Events occurring very early in life, even prenatally, may have long-term effects on future health and behaviour. The influence of poor foetal growth and gestational stress in the mother on the risk of emotional problems in offspring was reviewed.

METHOD

A selective review of the literature was undertaken.

RESULTS

Studies of preterm infants and infants born small for gestational age have shown increased levels of emotional problems across the lifespan. In general, studies examining maternal depression/anxiety during pregnancy and other indices of gestational stress have shown significant associations with emotional problems in children. The results of several studies also point to the importance of psychosocial and genetic factors in moderating associations.

CONCLUSION

Future research that focuses on identifying the mechanisms underlying these associations is needed. The moderating role of psychosocial and genetic risk factors is an important area in which future research should be directed. These findings have clinical implications for the provision of antenatal care.

Refining the attention deficit hyperactivity disorder phenotype for molecular genetic studies

It is well established that attention deficit hyperactivity disorder (ADHD) is a familial and highly heritable disorder. Consequently, much effort is being directed towards searching for specific susceptibility genes. There is a growing trend, across the field of complex disease genetics, towards undertaking secondary analyses based on refined phenotypic definitions and in testing whether specific susceptibility genes modify the phenotypic presentation of the disorder in question. It is crucial that good, empirically derived arguments are made before undertaking multiple analyses on different phenotype refinements. In this review article, we consider the evidence from genetic epidemiological studies as well as key clinical studies that provide guidance on examining the ADHD phenotype for the purpose of molecular genetic studies. Specifically, findings on categorical versus dimensional conceptualisations of ADHD, reporter effects, comorbidity, ADHD subtypes and persistence are reviewed. Current evidence suggests that for the purpose of identifying susceptibility genes for ADHD, parent and teachers should be used as informants and that focusing on the clinical diagnosis of ADHD is useful. There is also good empirical support in favour of examining antisocial behaviour in ADHD. Genetic studies of dimensional ADHD are useful for other complementary purposes.

Maternal smoking during pregnancy as an environmental risk factor for attention deficit hyperactivity disorder behaviour. A review

Attention deficit hyperactivity disorder (ADHD) is a common childhood psychiatric disorder which affects between 3% and 5% of school aged children. Despite much research, little is known regarding the aetiology of the disorder. Maternal cigarette smoking during pregnancy has been linked to a number of negative effects in offspring in infancy, childhood and even into adulthood and has been proposed as a possible risk factor for ADHD. The aim of this review was to discuss the evidence associating maternal smoking during pregnancy and ADHD as well as methodological issues concerning this association. A literature search using PubMed was employed using relevant keywords. The relevant reference sections of articles found were also searched. All English language studies published before June 2005 were assessed. A pooled odds ratio derived from case-control studies was also obtained. Despite methodological limitations, the majority of studies identify maternal smoking during pregnancy as a risk factor for ADHD behaviours. A pooled odds ratio indicates more than a two-fold increase in risk for a diagnosis of ADHD in those individuals whose mothers smoked during pregnancy (odds ratio 2.39, 95% confidence intervals 1.61, 3.52 P<0.001). Maternal smoking during pregnancy is a risk factor for ADHD behaviour and diagnoses, although the mechanisms through which such risks work is unknown.

No support for association between the dopamine transporter (DAT1) gene and ADHD

Several groups have reported an association between the 10-repeat allele of a dopamine transporter (DAT1) 3'UTR VNTR variant and ADHD but the finding has not been universally observed. An association between DAT1 genotype and stimulant medication response has also been reported although again there are conflicting data. We tested the DAT1 3'VNTR and three SNPs in the putative promoter region of DAT1 for association with ADHD in 263 parent-proband trios. Analyses of genotypes, alleles, and haplotypes were performed using family-based association methods. Case-control analysis of the VNTR in 263 cases and 287 controls was also conducted. In addition, we tested for association between the VNTR marker and stimulant medication response. Comparing allele 10 versus all other alleles combined, no significant association was found with ADHD, using FBAT analysis (chi2 = 0.1 (df 1), P = 0.9, (odds ratio (OR) = 1.0, 95% CI 0.8-1.2), and case-control analysis (chi2 = 0.12 (df 2), P = 0.91). No evidence of association with any of the SNPs in the promoter region was found. Haplotype analysis was also non-significant (chi2 = 3.93, (df 9) global P = 0.85). Finally, no association was found between the DAT 1 VNTR and response to stimulant medication (chi2 = 1.63 (df 3) P = 0.65). We conclude that the 3' VNTR and three additional promoter variants in DAT1 do not appear to be associated with ADHD, or response to stimulant mediation in our sample.

Association of the paternally transmitted copy of common Valine allele of the Val66Met polymorphism of the brain-derived neurotrophic factor (BDNF) gene with susceptibility to ADHD

Attention deficit hyperactivity disorder (ADHD) is a common, highly heritable, neurodevelopmental disorder with onset in early childhood. Genes involved in neuronal development and growth are, thus, important etiological candidates and brain-derived neurotrophic factor (BDNF), has been hypothesized to play a role in the pathogenesis of ADHD. BDNF is a member of the neurotrophin family and is involved in the survival and differentiation of dopaminergic neurons in the developing brain (of relevance because drugs that block the dopamine transporter can be effective therapeutically). The common Val66Met functional polymorphism in the human BDNF gene (rs 6265) was genotyped in a collaborative family-based sample of 341 white UK or Irish ADHD probands and their parents. We found evidence for preferential transmission of the valine (G) allele of BDNF (odds ratio, OR=1.6, P=0.02) with a strong paternal effect (paternal transmissions: OR=3.2, P=0.0005; maternal transmissions: OR=1.00; P=1.00). Our findings support the hypothesis that BDNF is involved in the pathogenesis of ADHD. The transmission difference between parents raises the possibility that an epigenetic process may be involved.

Attention deficit hyperactivity disorder with reading disabilities: preliminary genetic findings on the involvement of the ADRA2A gene

BACKGROUND

Attention deficit/hyperactivity disorder (ADHD) and reading disability (RD) tend to co-occur and quantitative genetic studies have shown this to arise primarily through shared genetic influences. However, molecular genetic studies have shown different genes to be associated with each of these conditions. Neurobiological studies have implicated noradrenergic function in the aetiology of ADHD that is comorbid with RD. This paper examines the neurobiological evidence and presents preliminary testing of the hypothesis that the ADRA2A receptor gene is contributing to ADHD and comorbid RD.

METHODS

One hundred and fifty-two children (140 boys, 12 girls) of British Caucasian origin, aged between 6 and 13 years and with a diagnosis of ADHD, were recruited. The children's reading ability was tested. Children were identified as having ADHD or ADHD plus RD (n=82). DNA was available for 110 parent child trios and 42 parent child duos. Genotyping was undertaken for an ADRA2A polymorphism.

RESULTS

For those with ADHD plus RD there was evidence of association with the alpha 2A adrenergic receptor (ADRA2A) polymorphism with the G allele being preferentially transmitted.

CONCLUSIONS

The preliminary evidence together with other neurobiological research findings suggests that the ADRA2A gene may contribute to comorbid ADHD and RD and needs to be properly examined.

Relationship between antisocial behaviour, attention-deficit hyperactivity disorder and maternal prenatal smoking

BACKGROUND

There is substantial evidence that maternal smoking during pregnancy is associated with both antisocial behaviour and symptoms of attention-deficit hyperactivity disorder (ADHD) in offspring. However, it is not clear whether maternal smoking during pregnancy is independently associated with antisocial behaviour or whether the association arises because antisocial behaviour and ADHD covary.

AIMS

To examine the relationship between maternal smoking during pregnancy, antisocial behaviour and ADHD in offspring.

METHOD

Questionnaires concerning behaviour and environmental factors were sent to twins from the CaStANET study and data analysed using a number of bivariate structural equation models.

RESULTS

Maternal prenatal smoking contributed small but significant amounts to the variance of ADHD and of antisocial behaviour. The best fitting bivariate model was one in which maternal prenatal smoking had a specific influence on each phenotype, independent of the effect on the other phenotype.

CONCLUSIONS

Both antisocial behaviour and ADHD symptoms in offspring are independently influenced by maternal prenatal smoking during pregnancy.

A family based study of catechol-O-methyltransferase (COMT) and attention deficit hyperactivity disorder (ADHD)

Neurobiological studies have suggested that altered dopaminergic function may contribute to the etiology of attention deficit hyperactivity disorder (ADHD). The gene encoding catechol-O-methyltransferase (COMT) is an attractive candidate for ADHD susceptibility as it plays a major role in the degradation of dopamine. Moreover, a functional Val158Met polymorphism in COMT that alters the activity of the encoded protein has been strongly implicated in frontal lobe function, with the high activity Valine allele being associated with poorer performance, and ADHD is thought to involve fronto-striatal pathways. We have examined this functional variant for association with ADHD in a family based association sample comprising 279 probands and their parents. We have also examined two other markers in the COMT gene (rs737865, rs165599) which, together with the Val/Met variant, have recently been shown to be associated with altered COMT expression rather than enzyme activity. No evidence for association was observed with any single marker or haplotype in a sample of 279 affected children and their parents.

Direct analysis of the genes encoding G proteins G alpha T2, G alpha o, G alpha Z in ADHD

We have followed up the extensive replicated evidence that the dopamine DRD4 receptor is involved in the aetiology of ADHD by undertaking direct analysis of genes encoding other proteins in this effector system. We prioritised the genes encoding G protein alpha subunits G alpha(T2), G alpha(o), G alpha(Z) as these have been shown to transduce the effects of ligand binding at DRD4. We screened the exons of all three genes for sequence variation in 28 unrelated subjects with ADHD and identified 13 novel polymorphisms. All were tested for possible association with ADHD using a combination of pooled and individual genotyping. The results of our study do not suggest that polymorphisms in these genes contribute to susceptibility to ADHD.

Follow-up of genetic linkage findings on chromosome 16p13: evidence of association of N-methyl-D aspartate glutamate receptor 2A gene polymorphism with ADHD

Attention deficit hyperactivity disorder (ADHD) is a childhood onset disorder, for which there is good evidence that genetic factors contribute to the aetiology. Recently reported linkage findings suggested evidence of a susceptibility locus on chromosome 16p13 (maximum LOD score of 4.2, P=5 x 10(-6)). The GRIN2A (glutamate receptor, ionotropic, N-methyl D-aspartate 2A) gene that encodes the N-methyl D-aspartate receptor subunit 2A (NMDA2A) maps to this region of linkage. As this is also a good functional candidate gene for ADHD, we undertook family-based association analysis in a sample of 238 families. We found significant evidence of association with a GRIN2A exon 5 polymorphism (chi(2)=5.7, P=0.01). Our data suggest that genetic variation in GRIN2A may confer increased risk for ADHD and that this, at least in part, might be responsible for the linkage result on 16p reported by Smalley et al. We conclude that replication is required and that further work examining for association of GRIN2A polymorphisms with ADHD is warranted.

Chromosome 22q11 deletions, velo-cardio-facial syndrome and early-onset psychosis. Molecular genetic study

BACKGROUND

Velo-cardio-facial syndrome (VCFS) is associated with interstitial deletions of chromosome 22q11. About 30% of patients with VCFS have psychosis, and the rate of these deletions in schizophrenia has been reported to be about 1%. Even higher rates of VCFS deletions have been reported for childhood-onset schizophrenia.

AIMS

To test the hypothesis that there is an increased rate of VCFS among patients with early-onset psychosis (age at onset <18 years). We screened 192 early-onset patients and 329 patients with adult-onset schizophrenia.

METHOD

We genotyped the patients and 444 healthy controls for hemizygosity of five microsatellite markers and one single nucleotide polymorphism that map to the 22q11-deleted region.

RESULTS

One patient had a VCFS deletion, confirmed with semi-quantitative polymerase chain reaction. None of the controls showed a pattern of genotypes consistent with hemizygosity.

CONCLUSIONS

VCFS may be less frequent among patients with psychosis than previously suggested; this rate is not increased among early-onset patients.

Evidence to suggest biased phenotypes in children with Attention Deficit Hyperactivity Disorder from completely ascertained trios

The transmission disequilibrium test (TDT) is widely used as a robust statistical method to test for genetic association due to linkage based upon analysis of parent-proband trios. The TDT and other family-based tests (eg haplotype relative risk method) are commonly used in association studies including those of ADHD because of concerns that the case-control design has a strong tendency for false positives due to poor matching between cases and controls. Unfortunately, it is not always possible to obtain DNA from both parents in studies of this design, even where the onset of disorder is in childhood, and usually the missing parent is the father. Despite the fact that methods exist for analysis where one parent is missing, many family-based studies are based on the collection or analysis of complete trios only. However this selection process might potentially introduce bias, particularly for studies of behavioural phenotypes like ADHD because the phenotype of proband or parents might influence family stability and therefore complete parental ascertainment. We set out to examine whether children with ADHD and for whom DNA samples from fathers were missing ('duos') differed phenotypically from children for whom genotype information was available from both parents ('trios'). Children from duos showed a significantly higher frequency of DMS-IV ADHD-combined type, significantly more co-morbid conduct disorder and conduct disorder symptoms, and a trend for higher total ADHD symptom scores. Excluding duos from sample collection and analysis may result in systematic bias. If comorbid conduct disorder and ADHD-combined type index increased genetic liability, exclusion of duos could further reduce the power of the TDT (and similar tests) to detect susceptibility genes for ADHD, or replicate effects detected by case-control analysis.

Serotonergic system and attention deficit hyperactivity disorder (ADHD): a potential susceptibility locus at the 5-HT(1B) receptor gene in 273 nuclear families from a multi-centre sample

Attention deficit hyperactivity disorder (ADHD) is a highly heritable and heterogeneous disorder, which usually becomes apparent during the first few years of childhood. Imbalance in dopamine neurotransmission has been suggested as a factor predisposing to ADHD. However, evidence has suggested an interaction between dopamine and serotonin systems in the pathophysiology of the disorder. Studies using selective agonists of the different 5-HT receptors microinjected into selected brain structures have shown a positive modulating effect on the functional activities of the mesotelencephalic dopaminergic system. This suggests that some of the genetic predisposition to ADHD might be due to DNA variation at serotonin system genes. In this study, we investigated polymorphisms in HTR(1B) and HTR(2A) (which encode the serotonin receptors 5-HT(1B) and 5-HT(2A) respectively) in a European ADHD sample. Using haplotype based haplotype relative risk (HHRR) and transmission disequilibrium test (TDT) analyses, we observed significant preferential transmission of the allele 861G of the HTR(1B) in the total sample (for HHRR; chi(2) = 7.4, P = 0.0065 and TDT; (chi(2) = 6.4, P = 0.014). Analysis of HTR(2A) failed to reveal evidence of association or linkage between the His452Tyr polymorphism and ADHD in the total sample. However, a significantly increased transmission of the allele 452His was observed in the Irish sample alone (chi(2) = 4.9, P = 0.026). These preliminary data suggest an important role for the serotonin system in the development of ADHD. Further studies, preferentially including different ethnic groups are required to substantiate these findings.

The development of a new site-specific measure of quality of life for breast problems: the Cardiff breast scales

The management of women presenting to primary care with symptoms of breast disease is of increasing interest given recent organisational changes aimed at improving accuracy and speed of referrals. As part of a randomised controlled trial, 1063 women were recruited following a primary care consultation for a variety of breast-related problems. In the absence of a suitable outcome measure for such women, a site-specific instrument was developed to complement a generic quality of life scale (SF-36). Items were generated using key informant interviews with health professionals. Draft scale items were piloted using a postal questionnaire and subsequent patient debrief interviews. A sample of respondents were also sent the same questionnaire I month later to assess test-retest reliability. Across the whole sample (n = 848), three factors were identified: 'general well-being', 'concerns' and 'relationships'. These factors accounted for 60% of total variance. Evidence of scale validity, reliability and responsiveness are reported for this new outcome measure for use in women presenting with breast problems.