			Home About us Contact

ADHD Subtypes (adhd + subtype)

Distribution by Scientific Domains

Life Sciences	62%

Selected Abstracts

An international multicenter association study of the serotonin transporter gene in persistent ADHD

GENES, BRAIN AND BEHAVIOR, Issue 5 2010
E. T. Landaas
Attention deficit hyperactivity disorder (ADHD) is a common behavioral disorder affecting children and adults. It has been suggested that gene variants related to serotonin neurotransmission are associated with ADHD. We tested the functional promoter polymorphism 5-HTTLPR and seven single nucleotide polymorphisms in SLC6A4 for association with ADHD in 448 adult ADHD patients and 580 controls from Norway. Replication attempts were performed in a sample of 1454 Caucasian adult ADHD patients and 1302 controls from Germany, Spain, the Netherlands and USA, and a meta-analysis was performed also including a previously published adult ADHD study. We found an association between ADHD and rs140700 [odds ratio (OR ) = 0.67; P = 0.01] and the short (S) allele of the 5-HTTLPR (OR = 1.19; P = 0.06) in the Norwegian sample. Analysis of a possible gender effect suggested that the association might be restricted to females (rs140700: OR = 0.45; P = 0.00084). However, the meta-analysis of 1894 cases and 1878 controls could not confirm the association for rs140700 [OR = 0.85, 95% confidence interval (CI) = 0.67,1.09; P = 0.20]. For 5-HTTLPR, five of six samples showed a slight overrepresentation of the S allele in patients, but meta-analysis refuted a strong effect (OR = 1.10, 95% CI = 1.00,1.21; P = 0.06). Neither marker showed any evidence of differential effects for ADHD subtype, gender or symptoms of depression/anxiety. In conclusion, our results do not support a major role for SLC6A4 common variants in persistent ADHD, although a modest effect of the 5-HTTLPR and a role for rare variants cannot be excluded. [source]

Lack of association of dopamine D4 receptor gene polymorphisms with ADHD subtypes in a population sample of twins

AMERICAN JOURNAL OF MEDICAL GENETICS, Issue 5 2001
Richard D. Todd
Abstract Attention-deficit hyperactivity disorder (ADHD) is a common, highly heritable syndrome of childhood characterized by problems with inattention, hyperactivity, and impulsivity. A variety of case control and family-based transmission distortion genetic studies of ADHD have focused on the possible involvement of polymorphisms of the DRD4 receptor gene. The majority of studies have examined the association of variously defined ADHD with an exon 3 polymorphism containing a variable number of imperfect 48 base pair repeats. Recently, McCracken et al. [2000: Mol Psych 5:531,536] reported an association of the DSM-IV primarily inattentive ADHD subtype with a 5, 120 base pair repeat polymorphism in the DRD4 gene. In this report, we test for the possible association of these two polymorphisms with population-derived samples of DSM-IV ADHD subtypes. Furthermore, we extend previous studies by testing for associations with ADHD subtypes derived from latent-class analysis of interview responses. In contrast to most, but not all, previous studies, we failed to demonstrate any significant association of the exon 3 7-repeat allele with ADHD. Nor did we replicate the association of the 5,120 base pair repeat polymorphism. We do find a significant association of the exon 3 3-repeat allele with a novel talkative/impulsive latent-class,defined subtype of ADHD. © 2001 Wiley-Liss, Inc. [source]

Inhibitory functioning across ADHD subtypes: Recent findings, clinical implications, and future directions

DEVELOPMENTAL DISABILITIES RESEARCH REVIEW, Issue 4 2008
Zachary W. Adams
Abstract Although growing consensus supports the role of deficient behavioral inhibition as a central feature of the combined subtype of ADHD (ADHD/C; Barkley 1997 Psychol Bull 121:65,94; Nigg 2001 Psychol Bull 127:571,598), little research has focused on how this finding generalizes to the primarily inattentive subtype (ADHD/I). This question holds particular relevance in light of recent work suggesting that ADHD/I might be better characterized as a disorder separate from ADHD/C (Diamond 2005 Dev Psychopathol 17:807,825; Milich et al. 2001 Clin Psychol Sci Pract 8:463,488). This article describes major findings in the area of inhibitory performance in ADHD and highlights recent research suggesting important areas of divergence between the subtypes. In particular, preliminary findings point to potential differences between the subtypes with respect to how children process important contextual information from the environment, such as preparatory cues that precede responses and rewarding or punishing feedback following behavior. These suggestive findings are discussed in the context of treatment implications, which could involve differential intervention approaches for each subtype targeted to the specific deficit profiles that characterize each group of children. Future research avenues aimed toward building a sound theoretical model of ADHD/I and a better understanding of its relation to ADHD/C are also presented. Specifically, investigators are encouraged to continue studying the complex interplay between inhibitory and attentional processes, as this area seems particularly promising in its ability to improve our understanding of the potentially distinct pathologies underlying the ADHD subtypes. © 2008 Wiley-Liss, Inc. Dev Disabil Res Rev 2008;14:268,275. [source]

Lack of association of dopamine D4 receptor gene polymorphisms with ADHD subtypes in a population sample of twins

Comparison of ADHD symptom subtypes as source-specific syndromes

THE JOURNAL OF CHILD PSYCHOLOGY AND PSYCHIATRY AND ALLIED DISCIPLINES, Issue 6 2004
Kenneth D. Gadow
Background:, This study examines differences between the three subtypes of attention-deficit/hyperactivity disorder (ADHD), inattentive (I), hyperactive-impulsive (H), and combined (C), in a heterogeneous sample of 248 boys (ages 6 to 10 years) with emotional and behavioral problems who were recruited for participation in a diagnostic study. Method:, The boys and their mothers participated in an extensive evaluation that involved multiple assessments of cognitive, behavioral, academic, and family functioning. ADHD subtypes were defined on the basis of teacher alone, mother alone, and mother/teacher ratings of DSM-IV symptoms. Results:, Results indicated ADHD symptom groups showed a differential pattern of impairment socially (H,C>I) and cognitively (I,C>H). The C and H groups were the most and least impaired overall, respectively, and all subtypes were differentiated from the nonADHD clinical control or NONE (N) group in a manner consistent with the primary findings. External validation of group differences was limited, and there were marked inconsistencies in the pattern of findings depending on how groups were defined. For the most part, although the mother/teacher grouping strategy (compared with either alone) captured a greater diversity of differences between subtypes, it also obscured some. Conclusions:, Observed findings are consistent with the notion that mothers and teachers interpret symptom statements in terms of behaviors that are most relevant for their daily concerns. [source]

Comparison of the play of children with attention deficit hyperactivity disorder by subtypes

AUSTRALIAN OCCUPATIONAL THERAPY JOURNAL, Issue 2 2010
Reinie Cordier
Background:,Studies have found differences in the nature and severity of social problems experienced by children with different subtypes of attention deficit hyperactivity disorder (ADHD). Given that play is often the context for acquiring social skills, there is surprisingly limited research examining whether these differences distinguish the play of children within the groups. Methods:,Using the Test of Playfulness (ToP), we examined the similarities and differences in play between children (aged 5,11 years) diagnosed with the threeDSM-IV ADHD subtypes: inattentive (I-subtype;n = 46), hyperactive-impulsive (HI-subtype;n = 28) and combined subtypes (C-subtype;n = 31). Results and conclusions:,Bias interaction, an item-by-item analysis, revealed that the hierarchy of ToP items was similar for children with the HI- and C-subtypes, but differed for children with the I-subtype. Specifically, children with the I-subtype found it more difficult to become intensely engaged in play and to take on playful mischief and clowning; however, they found social play items to be easier. Conversely, whereas mischief and clowning were relatively easier for children with the HI- and C-subtypes, many items reflecting social interaction were more difficult. These findings suggest that interventions can be tailored to these differing presentations. However, further research is needed to confirm the findings. [source]