Substance-Related Problems in Adolescents with ADHD-Diagnoses: The Importance of Self-Reported Conduct Problems

BACKGROUND

Attention-deficit/hyperactivity disorder (ADHD) is a known risk factor for substance-related problems (SRP) during adolescence, but the nature of this relationship and the importance of co-occurring conduct problems are not fully understood.

METHODS

Data stem from a linked dataset between a large population-based survey conducted in 2012 of Norwegian adolescents aged 16 to 19, and registry-based data from specialized child and adolescent mental health services (n = 9,411).

RESULTS

Adolescents with "ADHD + high conduct problems" had increased risk of SRP (odds ratios = 2.37-10.14). Adolescents with "ADHD only" had very similar risk of SRP as adolescents from the general population with low symptoms of conduct problems. Relative to boys, girls with "ADHD + high conduct problems" appeared to have somewhat higher risk for SRP.

CONCLUSION

The present study suggests that the risk for SRP among adolescent with ADHD is largely driven by co-existing conduct problems.

An Exploratory Investigation of Goal Management Training in Adults With ADHD: Improvements in Inhibition and Everyday Functioning

Background: Adults with attention deficit/hyperactivity disorder (ADHD) are predominantly treated with medication. However, there is also a need for effective, psychologically based interventions. As ADHD is strongly associated with reduced inhibitory control, cognitive remediation approaches should be efficient. Goal management training (GMT) aims at enhancing inhibitory control and has shown positive effects on inhibitory control in non-ADHD patient groups. The aim of the current study was to explore whether GMT would specifically enhance inhibitory control in adults with ADHD, and if such an enhancement would lead to secondary improvements in self-reported everyday functioning. Methods: Twenty-one participants with ADHD (mean age: 39.05 years [SD 11.93]) completed the intervention and assessments pre-, post- and 6 months after the intervention. Measures included neuropsychological tests and self-report questionnaires pertaining to cognitive- and executive functioning, emotion regulation, quality of life, and ADHD symptoms. Results: Compared to baseline, the participants showed enhanced inhibitory control on performance-based measures at post-assessment and 6-month follow-up. The participants also reported increased productivity and reduced cognitive difficulties in everyday life at both assessments post-treatment, as well as improvements in aspects of emotion regulation and a reduction in the severity of core ADHD-symptoms at 6-month follow-up. Conclusion: Our exploratory study showed that GMT seems to specifically improve one of the core executive dysfunctions in ADHD, namely inhibitory control, with a positive effect lasting at least 6 months post-treatment. The adults with ADHD also reported improved self-regulation in their everyday life after completing GMT, providing strong arguments for further investigations of GMT as a treatment option for this group of adults. Clinical Trial Registration: The study is registered under ISRCTN.com (ISRCTN91988877; https://doi.org/10.1186/ISRCTN91988877).

1q21.1 distal copy number variants are associated with cerebral and cognitive alterations in humans

Low-frequency 1q21.1 distal deletion and duplication copy number variant (CNV) carriers are predisposed to multiple neurodevelopmental disorders, including schizophrenia, autism and intellectual disability. Human carriers display a high prevalence of micro- and macrocephaly in deletion and duplication carriers, respectively. The underlying brain structural diversity remains largely unknown. We systematically called CNVs in 38 cohorts from the large-scale ENIGMA-CNV collaboration and the UK Biobank and identified 28 1q21.1 distal deletion and 22 duplication carriers and 37,088 non-carriers (48% male) derived from 15 distinct magnetic resonance imaging scanner sites. With standardized methods, we compared subcortical and cortical brain measures (all) and cognitive performance (UK Biobank only) between carrier groups also testing for mediation of brain structure on cognition. We identified positive dosage effects of copy number on intracranial volume (ICV) and total cortical surface area, with the largest effects in frontal and cingulate cortices, and negative dosage effects on caudate and hippocampal volumes. The carriers displayed distinct cognitive deficit profiles in cognitive tasks from the UK Biobank with intermediate decreases in duplication carriers and somewhat larger in deletion carriers-the latter potentially mediated by ICV or cortical surface area. These results shed light on pathobiological mechanisms of neurodevelopmental disorders, by demonstrating gene dose effect on specific brain structures and effect on cognitive function.

Examining the Subacute Effects of Mild Traumatic Brain Injury Using a Traditional and Computerized Neuropsychological Test Battery

This study investigates subacute cognitive effects of mild traumatic brain injury (MTBI) in the Trondheim Mild TBI Study, as measured, in part, by the neuropsychological test battery of the Collaborative European NeuroTrauma Effectiveness Research in TBI (CENTER-TBI) program, including computerized tests from the Cambridge Neuropsychological Test Automated Battery (CANTAB) and traditional paper-and-pencil tests. We investigated whether cognitive function was associated with injury severity: intracranial traumatic lesions on neuroimaging, witnessed loss of consciousness (LOC), or post-traumatic amnesia (PTA) >1 h. Further, we explored which of the tests in the CENTER-TBI battery might be associated with the largest subacute effects of MTBI (i.e., at 2 weeks post-injury). We recruited 177 patients with MTBI (16-59 years of age) from a regional trauma center and an outpatient clinic,79 trauma control participants, and 81 community control participants. The MTBI group differed from community controls only on one traditional test of processing speed (coding; p = 0.009, Cliff's delta [Δ] = 0.20). Patients with intracranial abnormalities performed worse than those without on a traditional test (phonemic verbal fluency; p = 0.043, Δ = 0.27), and patients with LOC performed differently on the Attention Switching Task from the CANTAB (p = 0.020, Δ = -0.20). Patients with PTA >1 h performed worse than those with <1 h on 10 measures, from traditional tests and the CANTAB (Δ = 0.33-0.20), likely attributable, at least in part, to pre-existing differences in intellectual functioning between groups. In general, those with MTBI had good neuropsychological outcome 2 weeks after injury and no particular CENTER-TBI computerized or traditional tests seemed to be more sensitive to subtle cognitive deficits.

Autism traits: The importance of "co-morbid" problems for impairment and contact with services. Data from the Bergen Child Study

BACKGROUND

Co-occurring problems are common in individuals with clinical autism spectrum disorder (ASD) but their relevance for impairment and contact with health services in ASD is largely unexplored.

AIMS

We investigated the extent of co-occurring problems in children with high ASD traits from a total population sample. We explored the contribution of co-occurring problems to impairment and service contact, and whether there were children without co-occurring problems in this group; as proxy for "ASD only".

METHODS AND PROCEDURES

Children screening positive on the Autism Spectrum Screening Questionnaire (ASSQ) were used as proxy for ASD. Attention Deficit/Hyperactivity Disorder (ADHD) and Oppositional Defiant Disorder (ODD) were operationalised using symptom counts. A parent or teacher report above the 95th percentile counted as "problem" present for other symptom domains.

OUTCOMES AND RESULTS

92% of ASSQ high-scorers had a minimum of two other problems. Emotional problems, ADHD symptoms and learning problems were the most commonly reported problems, also predicting impairment and contact with services.

CONCLUSIONS AND IMPLICATIONS

Co-occurring problems were common in ASD screen positive children and contributed strongly to both impairment and to contact with services. Gender differences indicated that female symptoms were perceived as less impairing by parents and teachers.

GWAS meta-analysis reveals novel loci and genetic correlates for general cognitive function: a report from the COGENT consortium

This corrects the article DOI: 10.1038/mp.2016.244.

Prevalence and clinical correlates of insomnia in adults with attention-deficit hyperactivity disorder

OBJECTIVE

To investigate the prevalence of insomnia in adults with Attention-deficit hyperactivity disorder (ADHD) and its association with clinical subtypes, current ADHD symptoms, and stimulant treatment.

METHOD

We obtained diagnostic information, symptom rating scales and treatment history from clinically ascertained adult ADHD patients diagnosed according to DSM-IV criteria (n = 268, mean age 38.1 years) and randomly selected population controls (n = 202, mean age 36.5 years). The Bergen Insomnia Scale (BIS) was used to measure insomnia. ADHD symptom domains were self-rated using the Adult ADHD Self-Rating Scale.

RESULTS

Insomnia was far more frequent among adults with ADHD (66.8%) than in the population controls (28.8%) (P < 0.001). Insomnia was more common in adults with the combined subtype than in those with the inattentive subtype (79.7% and 55.6%, respectively) (P = 0.003). For self-reported current ADHD symptoms, inattention was strongly correlated to insomnia. Patients currently using stimulant treatment for ADHD reported a lower total insomnia score compared to patients without medication (P < 0.05).

CONCLUSION

Insomnia was highly prevalent among adults with ADHD. The lower insomnia score in patients on current stimulant treatment suggests that stimulant treatment is not associated with worsening of insomnia symptoms in adult ADHD patients.

GWAS meta-analysis reveals novel loci and genetic correlates for general cognitive function: a report from the COGENT consortium

The complex nature of human cognition has resulted in cognitive genomics lagging behind many other fields in terms of gene discovery using genome-wide association study (GWAS) methods. In an attempt to overcome these barriers, the current study utilized GWAS meta-analysis to examine the association of common genetic variation (~8M single-nucleotide polymorphisms (SNP) with minor allele frequency ⩾1%) to general cognitive function in a sample of 35 298 healthy individuals of European ancestry across 24 cohorts in the Cognitive Genomics Consortium (COGENT). In addition, we utilized individual SNP lookups and polygenic score analyses to identify genetic overlap with other relevant neurobehavioral phenotypes. Our primary GWAS meta-analysis identified two novel SNP loci (top SNPs: rs76114856 in the CENPO gene on chromosome 2 and rs6669072 near LOC105378853 on chromosome 1) associated with cognitive performance at the genome-wide significance level (P<5 × 10^-8). Gene-based analysis identified an additional three Bonferroni-corrected significant loci at chromosomes 17q21.31, 17p13.1 and 1p13.3. Altogether, common variation across the genome resulted in a conservatively estimated SNP heritability of 21.5% (s.e.=0.01%) for general cognitive function. Integration with prior GWAS of cognitive performance and educational attainment yielded several additional significant loci. Finally, we found robust polygenic correlations between cognitive performance and educational attainment, several psychiatric disorders, birth length/weight and smoking behavior, as well as a novel genetic association to the personality trait of openness. These data provide new insight into the genetics of neurocognitive function with relevance to understanding the pathophysiology of neuropsychiatric illness.

Genome-wide autozygosity is associated with lower general cognitive ability

Inbreeding depression refers to lower fitness among offspring of genetic relatives. This reduced fitness is caused by the inheritance of two identical chromosomal segments (autozygosity) across the genome, which may expose the effects of (partially) recessive deleterious mutations. Even among outbred populations, autozygosity can occur to varying degrees due to cryptic relatedness between parents. Using dense genome-wide single-nucleotide polymorphism (SNP) data, we examined the degree to which autozygosity associated with measured cognitive ability in an unselected sample of 4854 participants of European ancestry. We used runs of homozygosity-multiple homozygous SNPs in a row-to estimate autozygous tracts across the genome. We found that increased levels of autozygosity predicted lower general cognitive ability, and estimate a drop of 0.6 s.d. among the offspring of first cousins (P=0.003-0.02 depending on the model). This effect came predominantly from long and rare autozygous tracts, which theory predicts as more likely to be deleterious than short and common tracts. Association mapping of autozygous tracts did not reveal any specific regions that were predictive beyond chance after correcting for multiple testing genome wide. The observed effect size is consistent with studies of cognitive decline among offspring of known consanguineous relationships. These findings suggest a role for multiple recessive or partially recessive alleles in general cognitive ability, and that alleles decreasing general cognitive ability have been selected against over evolutionary time.

Prevalence of auditory hallucinations in Norwegian adolescents: results from a population-based study

Knowing the prevalence and characteristics of auditory verbal hallucinations (AVH) in adolescents is important for estimations of need for mental health care and assessment of psychosis risk. In this report we assess the prevalence of AVH in a population-based sample of 16-19 years old Norwegian adolescents (n = 9,646, 46.4% male) using two items assessing AVH (from the extended Launay-Slade Hallucination Scale). The prevalence of hearing a voice speaking thoughts aloud was 10.6%. The prevalence of being troubled by voices was 5.3%, showing that negative emotionality about AVH is less frequent than the experience of hearing voices. Female respondents had slightly increased risk for being troubled by voices than males (odds ratio = 1.3), while age did not modulate prevalence. This AVH prevalence is in line with earlier reports in smaller samples of adolescents and indicates that AVH are not uncommon in this period of life. Further longitudinal studies are needed to investigate the value of AVH in predicting psychiatric disorder.

Genetic contributions to variation in general cognitive function: a meta-analysis of genome-wide association studies in the CHARGE consortium (N=53949)

General cognitive function is substantially heritable across the human life course from adolescence to old age. We investigated the genetic contribution to variation in this important, health- and well-being-related trait in middle-aged and older adults. We conducted a meta-analysis of genome-wide association studies of 31 cohorts (N=53,949) in which the participants had undertaken multiple, diverse cognitive tests. A general cognitive function phenotype was tested for, and created in each cohort by principal component analysis. We report 13 genome-wide significant single-nucleotide polymorphism (SNP) associations in three genomic regions, 6q16.1, 14q12 and 19q13.32 (best SNP and closest gene, respectively: rs10457441, P=3.93 × 10(-9), MIR2113; rs17522122, P=2.55 × 10(-8), AKAP6; rs10119, P=5.67 × 10(-9), APOE/TOMM40). We report one gene-based significant association with the HMGN1 gene located on chromosome 21 (P=1 × 10(-6)). These genes have previously been associated with neuropsychiatric phenotypes. Meta-analysis results are consistent with a polygenic model of inheritance. To estimate SNP-based heritability, the genome-wide complex trait analysis procedure was applied to two large cohorts, the Atherosclerosis Risk in Communities Study (N=6617) and the Health and Retirement Study (N=5976). The proportion of phenotypic variation accounted for by all genotyped common SNPs was 29% (s.e.=5%) and 28% (s.e.=7%), respectively. Using polygenic prediction analysis, ~1.2% of the variance in general cognitive function was predicted in the Generation Scotland cohort (N=5487; P=1.5 × 10(-17)). In hypothesis-driven tests, there was significant association between general cognitive function and four genes previously associated with Alzheimer's disease: TOMM40, APOE, ABCG1 and MEF2C.

Lack of association of the rs1344706 ZNF804A variant with cognitive functions and DTI indices of white matter microstructure in two independent healthy populations

The rs1344706 single nucleotide polymorphism within intron 2 of the ZNF804A gene is strongly associated with schizophrenia and bipolar disorder. This variant has also been associated in some studies with a range of cognitive and neuroimaging phenotypes, but several studies have reported no effect on the same phenotypes in other samples. Here, we genotyped 670 healthy adult Norwegian subjects and 1753 healthy adult Swedish subjects for rs1344706, and tested for associations with cognitive phenotypes including general intellectual abilities, memory functions and cognitive inhibition. We also tested whether rs1344706 is associated with white matter microstructural properties using diffusion tensor imaging (DTI) data from 250 to 340 of the Norwegian and Swedish subjects, respectively. Whole-brain voxel-wise statistical modeling of the effect of the ZNF804A variant on two DTI indices, fractional anisotropy (FA) and radial diffusivity (RD), was performed using tract-based spatial statistics (TBSS), and commonly reported effect sizes were calculated within several large-scale white matter pathways based on neuroanatomical atlases. No significant associations were found between rs1344706 and the cognitive traits or white matter microstructure. We conclude that the rs1344706 SNP has no significant effect on these phenotypes in our two reasonably powered samples.

Influence of assessment instrument on ADHD diagnosis

We compared four instruments commonly used to screen for and diagnose Attention-Deficit/Hyperactivity Disorder (ADHD) in children. The Bergen Child Study included a DSM-IV ADHD symptom list and the Strengths and Difficulties Questionnaire (SDQ) as screen in Phase one. Phase two included the parent Development and Well-Being Assessment (DAWBA), whereas Phase three comprised in-depth clinical assessment, including the Schedule for Affective Disorders and Schizophrenia for School Aged Children (K-SADS). We compared ADHD as diagnosed by the four instruments in the children with normal intellectual functioning participating in all three phases (N = 234). The DSM-IV ADHD symptom list showed moderate agreement with all other instruments (κ = 0.53-0.57), whereas there was fair agreement between the K-SADS-DAWBA (κ = 0.31) and between SDQ-DAWBA (κ = 0.33). The DAWBA diagnosed fewer children with ADHD than did the other instruments. Implications for use of the instruments are discussed.

Human cognitive ability is influenced by genetic variation in components of postsynaptic signalling complexes assembled by NMDA receptors and MAGUK proteins

Differences in general cognitive ability (intelligence) account for approximately half of the variation in any large battery of cognitive tests and are predictive of important life events including health. Genome-wide analyses of common single-nucleotide polymorphisms indicate that they jointly tag between a quarter and a half of the variance in intelligence. However, no single polymorphism has been reliably associated with variation in intelligence. It remains possible that these many small effects might be aggregated in networks of functionally linked genes. Here, we tested a network of 1461 genes in the postsynaptic density and associated complexes for an enriched association with intelligence. These were ascertained in 3511 individuals (the Cognitive Ageing Genetics in England and Scotland (CAGES) consortium) phenotyped for general cognitive ability, fluid cognitive ability, crystallised cognitive ability, memory and speed of processing. By analysing the results of a genome wide association study (GWAS) using Gene Set Enrichment Analysis, a significant enrichment was found for fluid cognitive ability for the proteins found in the complexes of N-methyl-D-aspartate receptor complex; P=0.002. Replication was sought in two additional cohorts (N=670 and 2062). A meta-analytic P-value of 0.003 was found when these were combined with the CAGES consortium. The results suggest that genetic variation in the macromolecular machines formed by membrane-associated guanylate kinase (MAGUK) scaffold proteins and their interaction partners contributes to variation in intelligence.

Posttraumatic responses to the July 22, 2011 Oslo Terror among Norwegian high school students

The July 22, 2011, Oslo Terror was defined as a national disaster. Former studies on terror attacks and mass shootings have shown elevated levels of posttraumatic complaints both in direct victims and in general populations. Little is known about how such extreme events in a generally safe society such as Norway would affect an adolescent population. This study examines posttraumatic stress reactions and changes in worldview in relationship to risk factors among 10,220 high school students using data from the ung@hordaland survey. One out of 5 respondents knew someone directly exposed, 55.7% experienced the events to some extent as threatening to their own or their close ones' lives, and 79.9% reported their worldview to be changed. For posttraumatic stress disorder (PTSD) DSM IV criteria, 0.8% reported substantial symptoms of reexperiencing (Criterion B), 4.9% of avoidance (Criterion C), and 1.1% of hyperarousal (Criterion D). Greater personal proximity to the events, higher levels of perceived life threat, and being a female or an immigrant predicted higher levels of PTSD symptom distress. Results indicate that the terror events made a deep impression on Norwegian adolescents, but without causing markedly elevated levels of PTSD symptomatology in the general young population.

Emotional development in children with tics: a longitudinal population-based study

Children with tics often experience accompanying problems that may have more impact on their well being and quality of life than the tics themselves. The present study investigates characteristics and the course of associated problems. In a population-based follow-up study, we investigated the developmental trajectory of children with and without tics when they were 7-9 years old. Parents and teachers completed the strengths and difficulties questionnaire (SDQ) when the children were 7-9 years (wave 1) and 4 years later (wave 2). Using strict criteria, we identified 38 children with tics in the cohort of 4,025 children (0.94% of the total cohort) with a preponderance of boys (78.9%). 22 children (57.9%) in the group with tics had only motor tics, and 16 (42.1%) had both motor and vocal tics. Children with tics had significantly higher parent- and teacher-rated SDQ total difficulty scores and subscale scores in both waves. Children with tics experienced an increase in emotional problems and in peer problems between the first and the second wave. This study in a general population indicates that the presence of tics is associated with a range of internalizing and externalizing difficulties, as well as problems in peer relationships. Moreover, our study indicates that emotional and peer problems tend to increase over time in the group of children with tics.

Representative Factor Generation for the Interactive Visual Analysis of High-Dimensional Data

Datasets with a large number of dimensions per data item (hundreds or more) are challenging both for computational and visual analysis. Moreover, these dimensions have different characteristics and relations that result in sub-groups and/or hierarchies over the set of dimensions. Such structures lead to heterogeneity within the dimensions. Although the consideration of these structures is crucial for the analysis, most of the available analysis methods discard the heterogeneous relations among the dimensions. In this paper, we introduce the construction and utilization of representative factors for the interactive visual analysis of structures in high-dimensional datasets. First, we present a selection of methods to investigate the sub-groups in the dimension set and associate representative factors with those groups of dimensions. Second, we introduce how these factors are included in the interactive visual analysis cycle together with the original dimensions. We then provide the steps of an analytical procedure that iteratively analyzes the datasets through the use of representative factors. We discuss how our methods improve the reliability and interpretability of the analysis process by enabling more informed selections of computational tools. Finally, we demonstrate our techniques on the analysis of brain imaging study results that are performed over a large group of subjects.

Oppositional defiant disorder-gender differences in co-occurring symptoms of mental health problems in a general population of children

Informant- and gender-specific characteristics of Oppositional Defiant Disorder (ODD) and how these might relate to patterns of comorbidity need to be further clarified. We collected data from 7,007 children (aged 7-9) who participated in the Bergen Child Study (BCS), an ongoing population-based study of children's development and mental health. A questionnaire containing the DSM-IV behavioral descriptions of ODD was distributed to parents and teachers. Co-occurring symptoms of mental health problems were measured by the Strengths and Difficulties Questionnaire (SDQ). The boys (n = 122) and girls (n = 41) with symptomatic ODD had an increased risk of co-occurring emotional symptoms, hyperactivity or inattention and peer problems, as compared to their peers without symptomatic ODD. The impact of symptomatic ODD was higher for boys than girls in teacher reported SDQ ratings, except for emotional symptoms. There were no significant interaction effects of gender in parent SDQ ratings. Our results are contrary to the gender paradox hypothesis, which states that co-occurring symptoms of mental health problems are more frequent among girls with ODD as compared to boys with ODD.

Emotional and behavioural problems in subgroups of children with chronic illness: results from a large-scale population study

BACKGROUND

Children with chronic illness are known to have an increased risk of emotional and behavioural problems. In the present population-based study children with asthma, neurological disorders and other chronic illnesses were compared with children without chronic illnesses to assess differences in psychological presentation across illness groups.

METHODS

A total of 537 children with parent-reported chronic illness in the Bergen Child Study were categorized into three groups: asthma, neurological disorders and other chronic illnesses. Emotional and behavioural problems were assessed by the Strengths and Difficulties Questionnaire.

RESULTS

All three illness groups had an increased rate of emotional and behavioural problems, as well as increased probability of a psychiatric disorder compared with children without a chronic illness. Most children with asthma and other chronic illnesses did not have emotional and behavioural problems, and effect sizes were small in both groups. In children with neurological disorders the effect sizes ranged from moderate to large, with emotional problems, inattention hyperactivity and peer problems being the most frequent problems.

CONCLUSIONS

The increased rate of emotional and behavioural problems in children with chronic illness, especially neurological disorders, emphasizes the importance of early detection of mental health problems in these children.

Association between catechol O-methyltransferase (COMT) haplotypes and severity of hyperactivity symptoms in adults

It has been suggested that symptoms of attention-deficit/hyperactivity disorder (ADHD) is related to low dopamine levels in the prefrontal cortex. The enzyme catechol O-methyltransferase (COMT), which degrades dopamine and other catecholamines, is important for monoamine signaling in this brain-region, but genetic studies of the functional Val158Met (rs4680) polymorphism in ADHD have been inconsistent. However, recently it was shown that also common synonymous COMT variants modulate total COMT enzymatic activity by affecting the expression of the gene [Nackley et al. (2006); Science 314(5807):1930-1933]. We therefore hypothesized that analysis of haplotypes could reveal more about the association between COMT and ADHD symptoms than the Val158Met polymorphism alone. SNPs rs6269, rs4633, rs4818, and rs4680, tagging the common putative functional COMT haplotypes, were genotyped in 435 adult subjects with a clinical diagnosis of ADHD and 383 controls and analyzed for association with ADHD and the hyperactivity/impulsivity and inattention dimensions from the Adult ADHD Self-Report Scale (ASRS). All markers showed a trend for association with the hyperactivity/impulsivity scale, peaking at marker rs6269 (P = 0.007). Haplotype analysis revealed that the rs6269 risk allele tags the suggested high COMT-activity haplotype, which is associated with the highest hyperactivity/impulsivity score in our sample (P = 0.01). Our results also suggest that there is a stepwise decreased hyperactivity/impulsivity score associated with the proposed mid and low activity haplotypes described previously. In conclusion, we suggest that COMT haplotype variation is associated primarily with the hyperactivity/impulsivity dimension of ADHD and point to the importance of testing this hypothesis in future studies.

Genetic analyses of dopamine related genes in adult ADHD patients suggest an association with the DRD5-microsatellite repeat, but not with DRD4 or SLC6A3 VNTRs

Attention deficit hyperactivity disorder (ADHD) is a common and highly heritable psychiatric disorder in children and adults. Recent meta-analyses have indicated an association between genes involved in dopaminergic signaling and childhood ADHD, but little is known about their possible role in adult ADHD. In this study of adults with ADHD, we evaluated the three most commonly studied ADHD candidate genetic polymorphisms; the dopamine receptor D4 (DRD4) exon 3 VNTR repeat, a microsatellite repeat 18.5 kb upstream of the DRD5 locus and the 3'UTR dopamine transporter SLC6A3 (DAT 1) VNTR. We examined 358 clinically diagnosed adult Norwegian ADHD patients (51% males) and 340 ethnically matched controls. We found a nominally significant overall association with adult ADHD for the DRD5 microsatellite marker (P = 0.04), and a trend toward increased risk associated with the 148-bp allele consistent with recent meta-analyses. The strongest overall association (P = 0.02) and increased risk for the 148-bp allele [odds ratio (OR) = 1.27 (95% CI: 1.00-1.61)] were seen in the inattentive and combined inattentive/hyperactive group as previously reported for childhood ADHD. No association was found for the DRD4 or SLC6A3 polymorphisms in this patient sample. In conclusion, our results among adults with a clinical diagnosis of ADHD support an association between ADHD and the DRD5 locus, but not the DRD4 or SLC6A3 loci. It is possible that the latter polymorphisms are associated with a transient form of ADHD with better long-term clinical outcome.

Emotional symptoms in inattentive primary school children: a population-based study

OBJECTIVE

The present study investigates teacher and parent reports of inattention and emotional symptoms in 6,229 primary school children.

METHOD

The assessment included the Emotional Symptoms subscale and the Impact scale from the Strengths and Difficulties Questionnaire and the inattention items from the Swanson, Nolan, and Pelham IV Questionnaire.

RESULTS

Children defined as inattentive showed a high risk of being defined as high scorers on the Emotional Symptoms subscale. A high score on both the Inattention and Emotional Symptoms subscales was associated with a high impact score. Teachers but not parents reported a higher risk of such co-occurrence of symptoms in girls than in boys.

CONCLUSION

Inattentive children should be screened for emotional problems by use of the multi-informants method.

General psychopathology is more important for executive functioning than diagnosis

OBJECTIVE

Impaired executive functioning (EF) has often been reported in patients with major depression or schizophrenia. We hypothesize that the variance in EF is more affected by level of general psychopathology than by diagnosis.

METHOD

Forty-three patients with major depression and 47 with schizophrenia were included. EF was measured with Wisconsin Card Sorting Test, Stroop Colour Word Test, Paced Auditory Serial Addition Test, Digits Backwards and Controlled Oral Word Association Test. The level of general psychopathology was measured with Brief Psychiatric Rating Scale - Expanded and Positive and Negative Syndrome Scale, the General psychopathology subscale.

RESULTS

The level of general psychopathology predicted more of the variance in EF than diagnosis. In multivariate analyses, the effect of general psychopathology on EF was more robust for adjustment for diagnosis than vice versa.

CONCLUSION

Future research on cognitive functioning in psychiatric patients should include level of general psychopathology to avoid overemphasising effects of diagnoses.

Dichotic memory: paradoxical effect of removing a left frontal gyrus: a case study

A 27-year-old right-handed woman was operated with resection of an epileptogenic lesion, a nonmalignant tumor, in the left frontal lobe. The surrounding cortical and subcortical tissue in the tumor-containing gyrus was also resected. Care was taken during the operation not to interfere with motor or language related cortical areas. Pre- and postoperatively, she was tested with a dichotic memory test. In the preoperative test, she showed a marked Left Ear Advantage. In the corresponding tests on the second and fourth postoperative days and at follow-up, her performance had changed to a Right Ear Advantage. A possible explanation of this result is that neighboring cortical areas involved in hemispheric specialization for lateralized, verbal cognitive functions are suppressed by a focal epiletogeneic activity caused by the tumor. The subsequent removal of this influence allowed these cortical areas to function normally.

Dichotic-listening performance and intracarotid injections of amobarbital in children and adolescents. Preoperative and postoperative comparisons

BACKGROUND

Dichotic listening (DL) to consonant-vowel syllables is frequently used in clinical and experimental studies of brain laterality. However, the paradigm of consonant-vowel syllables has not been thoroughly validated through a comparison with injections of amobarbital sodium (Amytal).

OBJECTIVE

To validate the DL test for hemisphere dominance preoperatively vs postoperatively with the results from intracarotid injections of amobarbital (i.e., the Wada test) in epileptic children and adolescents.

DESIGN AND MAIN OUTCOME MEASURES

Patients were tested with DL preoperatively and at 6-month follow-up. Correct reports in the DL tests were entered in a stepwise discriminant analysis for calculation of correct classification of hemisphere dominance with the results from the injections of amobarbital as the grouping variable. Correct reports from the right and left ears on the consonant-vowel DL test were compared preoperatively and postoperatively, separated for the subjects with regard to language dominance in the left and right hemispheres.

SETTING

The Department of Pediatrics, Ostra Hospital, University of Göteborg, Göteborg, Sweden.

PATIENTS

Thirteen children and adolescents between the ages of 10 and 19 years, who were surgically treated for resistant epilepsy, were included in the study. The operated area corresponded with morphological changes and functional dysfunctions according to findings from computed tomography, magnetic resonance imaging, single photon emission computed tomography, and electroencephalography.

RESULTS

The results of the Wada tests revealed that 10 subjects had left hemisphere language dominance, with 3 subjects having right hemisphere language dominance. All 3 subjects with right hemisphere language dominance showed a left ear advantage on the DL test preoperatively and postoperatively, with 8 and 7 of the 10 subjects with left hemisphere dominance showing a right ear advantage, preoperatively and postoperatively, respectively. However, according to discriminant analysis, knowledge of the DL performance led to a correct classification according to the Wada test results in 12 (92%) of the 13 subjects.

CONCLUSIONS

A quantitative classification procedure like discriminant analysis may be more sensitive when predicting hemisphere speech dominance from DL data than a qualitative procedure based on the ear advantage dichotomy. The ear advantage dichotomy may actually introduce arbitrary left-right categories that do not correspond to the actual clustering of the data.

Variability in cognitive function among persons at high genetic risk of Huntington's disease

The present study explores cognitive variability and specificity of cognitive decline in persons at high genetic risk (AR+ persons) of Huntington's disease (HD). Risk status was determined by RFLP markers. Three subgroups were defined according to neuropsychological test performance. One subgroup showed a typical HD pattern of impairment, a second group selectively impaired verbal memory function, and a third group was more heterogeneous. Verbal memory function was frequently impaired among AR+ persons. The specificity of verbal memory dysfunction was evaluated by using a multivariate statistical clustering procedure. While 60% of the AR+ persons were allocated to clusters typical of "subcortical dementia", most AR- persons were allocated to a "normal" cluster. However, the variability was wide within both the AR+ and AR- group. The heterogeneity among AR+ persons was consistent with findings in genetic, neuroimaging, and neuropathological studies of HD. Multidisciplinary studies should be performed to better understand biological determinants of cognitive variability, and to facilitate clinical diagnosis and councelling in individual AR+ persons.

Assessment of 'subcortical dementia' in patients with Huntington's disease, Parkinson's disease, multiple sclerosis and AIDS by a neuropsychological screening battery

Four diagnostic groups categorized as 'subcortical dementia' were studied using a neuropsychological screening battery. The specificity of the battery in disclosing characteristic patterns of impairment in subgroups within the category, and the correspondence between natural subgroups generated by an unsupervised statistical classification technique and the diagnostic labels were investigated. All cognitive affected subgroups demonstrated impairment on tests of sensomotor function, cognitive efficiency and/or memory, and were characterized in terms of severity of impairment as well as a progressive involvement of functional areas. The diagnostic groups were not evenly represented in all natural subgroups. Affected AIDS-patients seemed to resemble patients with Huntington's disease more than the other diagnostic groups. The screening battery could give a general characterization of the pattern of 'subcortical dementia' and different levels of impairment, but more specific process-oriented tasks are needed to contrast diagnostic groups within the concept of 'subcortical dementia'.

Characteristic patterns of verbal memory function in patients with Huntington's disease

Various aspects of verbal memory in patients with Huntington's disease (HD) were studied using the California Verbal Learning Test (CVLT). We tested if the level and interplay between 5 parameters of different memory mechanisms and processes were sufficiently specific to allow acceptable discrimination between patients with HD, patients with Parkinson's disease (PD), and patients without known CNS disease or injury. The HD-patients were characterized by a deficit in acquisition, elevated rates of recall errors and increased use of a passive learning strategy. Preserved aspects were shown in retention over time, interference effects and recognition relative to recall. Employing multivariate classification and validation techniques, the 5 CVLT-features demonstrated good separability between the HD-patients and the control patients. Qualitative similarities between subgroups were suggested, but more disease-specific data seemed necessary in further studies. A number of findings suggested a defect in the active organization of items to be encoded and recalled in HD. Similar findings in the PD-group might indicate that this trait is common in several types of 'subcortical dementia'.

Neuropsychological findings and depressive symptoms in patients with Huntington's disease

Twenty patients with Huntington's disease (HD) and a comparison group were studied by a depression scale (MADRS) and a neuropsychological test-battery assessing central areas of cognitive function. The main purpose was to analyze the consistency of findings across patients and focus on the role of specific factors in the impairments. The HD-patients are impaired relative to norms and the comparison-group in all areas but verbal conceptual function. We further divided the HD-patients into subgroups according to severity of neuropsychological impairment. The groups generally show a pattern of increasing deficits. Early changes are found in tests of cognitive efficiency, memory and sensomotor function, but the pattern of impairment is variable. The more severely affected subgroups show an increased decline in performance and progressive involvement of a broader range of functions. The pattern of depressive symptoms in HD-patients indicates that cognitive symptoms of concentration difficulties and lassitude are prominent in all subgroups.