Umesh Jain

Executive Functions: Performance-Based Measures and the Behavior Rating Inventory of Executive Function (BRIEF) in Adolescents with Attention Deficit/Hyperactivity Disorder (ADHD)

Performance-based measures and ratings of executive functions were examined in a sample of adolescents with attention deficit/hyperactivity disorder (ADHD) and comparison controls. Performance-based measures of executive function included inhibition, working memory, set shifting, and planning, and ratings of these same executive functions were completed by parents and teachers. Adolescents with ADHD demonstrated lower executive function performance than controls and displayed elevated ratings on the executive function ratings by parents and teachers. Significant associations were obtained between the performance-based measures and the parent and teacher ratings, but each measure was not uniquely associated with its respective scale on the rating scales. When performance-based measures and ratings were examined as predictors of ADHD status, the parent and teacher ratings entered as significant predictors of ADHD status. Further commonality analyses indicated that performance-based measures accounted for little unique variance in predicting ADHD status and also displayed little overlap with the behavioral ratings. These findings highlight the diagnostic utility of behavioral ratings of executive function in predicting ADHD status; however, behavioral ratings should not be assumed to be a proxy for performance on measures of executive function in clinical practice.

Executive and motivational processes in adolescents with Attention-Deficit-Hyperactivity Disorder (ADHD)

BackgroundThe objective of the current study was to examine performance and correlates of performance on a decision-making card task involving risky choices (Iowa Gambling Task) in adolescents with ADHD and comparison controls. Forty-four participants with ADHD and 34 controls were administered measures of estimated intellectual ability, working memory, and the card task. Also, behavioural ratings were obtained from parents and teachers.ResultsAdolescents with ADHD scored lower on the measures of intellectual ability, working memory, and made less advantageous selections on the card task compared to controls. Performance on measures of intellectual ability and working memory were unrelated to card task performance in both the ADHD and control samples. Parent ratings of hyperactivity/impulsivity were significantly associated with card task performance in the adolescents with ADHD, but not in controls.ConclusionThese findings demonstrate impaired decision-making in adolescents with ADHD, and the separability of motivational and executive function processes, supporting current dual pathway models of ADHD.

Adult attention deficit hyperactivity disorder and the dopamine D4 receptor gene.

Attention deficit hyperactivity disorder (ADHD) is a prevalent psychiatric condition in children and follow up studies have indicated that 22-33% of patients continue to suffer from ADHD during late adolescence and adulthood. Convincing evidence supports the contribution of genetic factors in the etiology of ADHD, and the interaction of the psychostimulants with the dopamine system suggests that dopamine is involved in the pathophysiology. The 7-repeat allele of the 48 base pair repeat of the dopamine D4 receptor gene (DRD4) has been reported, with several replications, to be associated with ADHD in children. We tested for the presence of association between the DRD4 48 base repeat and adult ADHD in two independent samples: one comprised of cases and ethnically matched controls, and the second made up of nuclear families. Each case was assessed using a battery of adult ADHD assessment instruments. The analysis of the 66 cases and 66 controls showed a significantly higher presence of the 7-repeat in the adult ADHD patients vs. controls (chi(2) = 5.65; df = 1; P = 0.01). In the analysis of transmission of DRD4 alleles in 44 nuclear families with the transmission disequilibrium test, a trend was observed toward a increased transmission of the 7-repeat from the heterozygous parents to the affected offspring (chi(2) = 2.00; df = 1; P = 0.15). When the two samples were combined, the overall significance was stronger (N = 110; z = 2.68; P = 0.003). The results of our study suggest a role of the 7-repeat allele in adult subjects suffering from ADHD. This finding is an important continuation of the group of studies that together strongly suggest the involvement of DRD4 in ADHD.

Sleep in attention-deficit/hyperactivity disorder in children and adults: Past, present, and future

The understanding that sleep can give rise to, or exacerbate symptoms of attention-deficit/hyperactivity disorder (ADHD), and that good sleep hygiene improves attention and concentration tasks has sparked interest in the investigation of possible etiological relationships between sleep disorders and ADHD. Studies indicate that 30% of children and 60-80% of adults with ADHD have symptoms of sleep disorders such as daytime sleepiness, insomnia, delayed sleep phase syndrome, fractured sleep, restless legs syndrome, and sleep disordered breathing. The range and diversity of findings by different researchers have posed challenges in establishing whether sleep disturbances are intrinsic to ADHD or whether disturbances occur due to co-morbid sleep disorders. As a result, understanding of the nature of the relationship between sleep disturbances/disorders and ADHD remains unclear. In this review, we present a comprehensive and critical account of the research that has been carried out to investigate the association between sleep and ADHD, as well as discuss mechanisms that have been proposed to account for the elusive relationship between sleep disturbances, sleep disorders, and ADHD.

The Unity and Diversity of Inattention and Hyperactivity/Impulsivity in ADHD: Evidence for a General Factor with Separable Dimensions

To examine the unity and diversity of inattention and hyperactivity/impulsivity symptom domains of Attention-Deficit/Hyperactivity Disorder (ADHD) in a clinical sample of adolescents with ADHD. Parents and adolescents were administered a semi-structured diagnostic interview, the Schedule for Affective Disorders and Schizophrenia for School-Age Children — Present and Lifetime Version (K-SADS-PL), to assess adolescent ADHD. Data from 201 parent interviews and 189 adolescent interviews were examined. Four potential factor structures for the 18 ADHD symptoms were tested using confirmatory factor analysis: two models with correlated factors and two bifactor models. A bifactor model with two specific factors best accounted for adolescent symptoms, according to both parent and adolescents’ reports. Replication of these findings from behavioral rating scales completed for this sample by parents and teachers indicates that the findings are not method– or informant-specific. The results suggest that there is an important unitary component to ADHD symptoms and separable dimensional traits of Inattention and Hyperactivity/Impulsivity.

Childhood inattention and dysphoria and adult obesity associated with the dopamine D4 receptor gene in overeating women with seasonal affective disorder

There is significant evidence that altered dopamine activity plays a role in seasonal affective disorder (SAD). The current study examined three separate genetic hypotheses for SAD related to the 7-repeat allele (7R) of the dopamine-4 receptor gene (DRD4), a variant associated with decreased affinity for dopamine. We examined the possible contribution of 7R to the overall expression of SAD, attention deficit disorder (ADD) comorbidity, and body weight regulation. As part of an ongoing genetic study of increased eating behavior and mood in female subjects, 108 women with winter SAD and carbohydrate craving/weight gain were administered the Wender-Utah Rating Scale to measure childhood ADD symptomatology, and a questionnaire to assess maximal lifetime body mass index (BMI). To test for an association between 7R and the categorical diagnosis of SAD, the transmission disequilibrium test (TDT) was used in a subsample of probands providing familial DNA. Standard parametric tests were used to compare childhood ADD symptoms and maximal lifetime BMI across the two genotypic groups defined by the presence or absence of 7R. The TDT found no initial evidence for an association between 7R and the categorical diagnosis of SAD. However, 7R carriers reported significantly greater inattention and dysphoria in childhood (p=0.01 and 0.001, respectively) and a higher maximal lifetime BMI (p=0.007) than did probands without this allele. Furthermore, excluding probands with extreme obesity (maximal BMI >40), a strong correlation was found linking childhood inattentive symptoms and maximal lifetime BMI (r=0.35, p=0.001). In overeating women with SAD, the 7R allele of DRD4 may be associated with a unique developmental trajectory characterized by attentional deficits and dysphoria in childhood and mild to moderate obesity in adulthood. This developmental course may reflect different manifestations of the same underlying vulnerability related to central dopamine dysfunction. Given the possibility of population stratification when studying genotype/phenotype relationships, future use of genomic controls and replication of our findings in other overeating and/or ADD populations are needed to confirm these initial results.

Pathways to Pathological Gambling: Component Analysis of Variables Related to Pathological Gambling

This study used principal components analysis to examine the structure of variables associated with pathological gambling. A large battery of questionnaires was administered to a sample of 141 gamblers who ranged from non-problem gamblers to severe pathological gamblers. We found a significant relationship between severity of pathological gambling and various measures of impulsivity, depression, anxiety, erroneous beliefs, and reports of early wins. Component analysis of these variables found four distinct components: emotional vulnerability, impulsivity, erroneous beliefs, and the experiences of wins. Component scores based on these components were regressed onto pathological gambling. Emotional vulnerability had the largest effect (β = 0.54), followed by early wins (β = 0.32), erroneous beliefs (β = 0.31), and impulsivity (β = 0.23). The overall model accounted for 53.4% of the variance of pathological gambling. The findings confirm the idea that there may be several different risk factors that explain the development of pathological gambling.

Association study of brain-derived neurotrophic factor (BDNF) and LIN-7 homolog (LIN-7) genes with adult attention-deficit/hyperactivity disorder.

Attention‐deficit/hyperactivity disorder (ADHD) is a common psychiatric disorder with a large genetic component that has been shown to persist into adulthood in 30–60% of childhood ADHD cases. Adult ADHD confers an increased risk of ADHD in relatives when compared to childhood ADHD, possibly due to a greater genetic liability than the childhood form. Brain‐derived neurotrophic factor (BDNF) is a neurotrophin expressed in the brain throughout life and is involved in survival, differentiation, and synaptic plasticity of several neuronal systems including dopaminergic pathways. Mammalian LIN‐7 homolog is selectively expressed in specific neuronal populations and is involved in the postsynaptic density of neuronal synapses. LIN‐7 is also a positional candidate, as it lies immediately downstream of BDNF. We tested for association between five BDNF polymorphisms, two LIN‐7 polymorphisms and adult ADHD. The sample consisted of 80 trios comprised of an adult ADHD proband and their biological parents and an independent sample of 121 adult ADHD cases and a corresponding number of sex, age, and ethnically matched controls (total 201 probands). Allelic and haplotype association was found between both BDNF and adult ADHD, and LIN‐7 and adult ADHD. HapMap indicates BDNF and LIN‐7 occur in different haplotype blocks, though some linkage disequilibrium exists between the SNPs in these adjacent genes. Further investigations into the pathologic mechanisms of BDNF and LIN‐7 in adult ADHD are required.

The Relationship of Problem Gambling to Criminal Behavior in a Sample of Canadian Male Federal Offenders

This article examines the prevalence of moderate and severe problem gambling in a sample of 254 incarcerated Canadian male federal offenders (completion rate of 39.0%). The prevalence of disordered gambling was measured using the PGSI, DSM-IV-TR, and SOGS that yielded estimates of 9.4%, 6.3%, and 13.0%, respectively. Severe problem gamblers were significantly more likely to have committed income producing offences, but were neither more nor less likely than other offenders to have committed violent offences. The majority of severe problem gamblers (65.2%) and a fifth of the moderate problem gamblers (20.0%) reported that their criminal activity was a result of their gambling (e.g., to pay off debts). Based on these findings there appears to be a need to offer problem gambling treatment services to offenders in order to help them break the cycle of gambling, debt and crime.

A Quantitative Trait Locus Analysis of the Dopamine Transporter Gene in Adults with ADHD

Numerous lines of evidence have shown that attention deficit hyperactivity disorder (ADHD) is a highly heritable disorder, whether it is considered as a category or a dimension. We tested for an association between the dopamine transporter gene (DAT1) and ADHD considering the disorder as categorical as well as a continuous trait. Genotypes for the DAT1 variable number of tandem repeat (VNTR) alleles, along with Brown Attention Deficit Disorder Scale (BADDS) and Wender Utah Rating Scale (WURS) scores were available for 152 adult ADHD patients. In 72 of these patients DNAs from at least one parent were accessible to perform a family-based analysis (FBAT). The mean quantitative trait values of the whole sample of singleton patients were compared among the specific genotype groups using ANOVA. The family-based analysis did not reveal any association between DAT1 alleles and ADHD either when it was considered as a dichotomous trait (Z = 0.16, p = .86) or as a continuous trait (Wender Scale Z = −1.67, p = .09; Brown ADD Scale Z = 0.28, p = .77). No significant differences were detected in the mean symptom scores among the specific genotype groups. The results from our study do not support a major role for the DAT1 VNTR alleles in our sample of adult ADHD. In view of several positive reports in child ADHD, more work is required to elucidate the potential role of the DAT1 VNTR as a risk factor in ADHD.