@article{BrevikvanDonkelaarWeberetal.2016,
  author    = {Brevik, Erlend J and van Donkelaar, Marjolein M. J. and Weber, Heike and S{\´a}nchez-Mora, Cristina and Jacob, Christian and Rivero, Olga and Kittel-Schneider, Sarah and Garcia-martinez, Iris and Aebi, Marcel and van Hulzen, Kimm and Cormand, Bru and Ramos-Quiroga, Josep A and Lesch, Klaus-Peter and Reif, Andreas and Ribases, Marta and Franke, Barbara and Posserud, Maj-Britt and Johansson, Stefan and Lundervold, Astri J. and Haavik, Jan and Zayats, Tetyana},
  title     = {Genome-wide analyses of aggressiveness in attention-deficit hyperactivity disorder},
  series = {American Journal of Medical Genetics Part B-Neuropsychiatric Genetics},
  volume    = {171B},
  journal   = {American Journal of Medical Genetics Part B-Neuropsychiatric Genetics},
  number    = {5},
  organization    = {IMAGE Consortium},
  doi       = {10.1002/ajmg.b.32434},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-188116},
  pages     = {733-747},
  year      = {2016},
  abstract  = {Aggressiveness is a behavioral trait that has the potential to be harmful to individuals and society. With an estimated heritability of about 40\%, genetics is important in its development. We performed an exploratory genome-wide association (GWA) analysis of childhood aggressiveness in attention deficit hyperactivity disorder (ADHD) to gain insight into the underlying biological processes associated with this trait. Our primary sample consisted of 1,060 adult ADHD patients (aADHD). To further explore the genetic architecture of childhood aggressiveness, we performed enrichment analyses of suggestive genome-wide associations observed in aADHD among GWA signals of dimensions of oppositionality (defiant/vindictive and irritable dimensions) in childhood ADHD (cADHD). No single polymorphism reached genome-wide significance (P<5.00E-08). The strongest signal in aADHD was observed at rs10826548, within a long noncoding RNA gene (beta = -1.66, standard error (SE) = 0.34, P = 1.07E-06), closely followed by rs35974940 in the neurotrimin gene (beta = 3.23, SE = 0.67, P = 1.26E-06). The top GWA SNPs observed in aADHD showed significant enrichment of signals from both the defiant/vindictive dimension (Fisher's P-value = 2.28E-06) and the irritable dimension in cADHD (Fisher's P-value = 0.0061). In sum, our results identify a number of biologically interesting markers possibly underlying childhood aggressiveness and provide targets for further genetic exploration of aggressiveness across psychiatric disorders.},
  language  = {en}
}
@article{NeufangAkhrifHerrmannetal.2016,
  author    = {Neufang, S. and Akhrif, A. and Herrmann, C.G. and Drepper, C. and Homola, G.A. and Nowak, J. and Waider, J. and Schmitt, A.G. and Lesch, K.-P. and Romanos, M.},
  title     = {Serotonergic modulation of 'waiting impulsivity' is mediated by the impulsivity phenotype in humans},
  series = {Translational Psychiatry},
  journal   = {Translational Psychiatry},
  number    = {6},
  doi       = {10.1038/tp.2016.210},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-164418},
  pages     = {e940},
  year      = {2016},
  abstract  = {In rodents, the five-choice serial reaction time task (5-CSRTT) has been established as a reliable measure of waiting impulsivity being defined as the ability to regulate a response in anticipation of reinforcement. Key brain structures are the nucleus accumbens (NAcc) and prefrontal regions (for example, pre- and infralimbic cortex), which are, together with other transmitters, modulated by serotonin. In this functional magnetic resonance imaging study, we examined 103 healthy males while performing the 5-CSRTT measuring brain activation in humans by means of a paradigm that has been widely applied in rodents. Subjects were genotyped for the tryptophan hydroxylase-2 (TPH2; G-703T; rs4570625) variant, an enzyme specific for brain serotonin synthesis. We addressed neural activation patterns of waiting impulsivity and the interaction between the NAcc and the ventromedial prefrontal cortex (vmPFC) using dynamic causal modeling. Genetic influence was examined via interaction analyses between the TPH2 genotype (GG homozygotes vs T allele carriers) and the degree of impulsivity as measured by the 5-CSRTT. We found that the driving input of the vmPFC was reduced in highly impulsive T allele carriers (reflecting a reduced top-down control) in combination with an enhanced response in the NAcc after correct target processing (reflecting an augmented response to monetary reward). Taken together, we found a high overlap of our findings with reports from animal studies in regard to the underlying cognitive processes, the brain regions associated with waiting impulsivity and the neural interplay between the NAcc and vmPFC. Therefore, we conclude that the 5-CSRTT is a promising tool for translational studies.},
  language  = {en}
}
@article{ZayatsJacobsenKleppeetal.2016,
  author    = {Zayats, T and Jacobsen, KK and Kleppe, R and Jacob, CP and Kittel-Schneider, S and Ribas{\´e}s, M and Ramos-Quiroga, JA and Richarte, V and Casas, M and Mota, NR and Grevet, EH and Klein, M and Corominas, J and Bralten, J and Galesloot, T and Vasquez, AA and Herms, S and Forstner, AJ and Larsson, H and Breen, G and Asherson, P and Gross-Lesch, S and Lesch, KP and Cichon, S and Gabrielsen, MB and Holmen, OL and Bau, CHD and Buitelaar, J and Kiemeney, L and Faraone, SV and Cormand, B and Franke, B and Reif, A and Haavik, J and Johansson, S},
  title     = {Exome chip analyses in adult attention deficit hyperactivity disorder},
  series = {Translational Psychiatry},
  volume    = {6},
  journal   = {Translational Psychiatry},
  number    = {e923},
  doi       = {10.1038/tp.2016.196},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-168297},
  year      = {2016},
  abstract  = {Attention-deficit/hyperactivity disorder (ADHD) is a highly heritable childhood-onset neuropsychiatric condition, often persisting into adulthood. The genetic architecture of ADHD, particularly in adults, is largely unknown. We performed an exome-wide scan of adult ADHD using the Illumina Human Exome Bead Chip, which interrogates over 250 000 common and rare variants. Participants were recruited by the International Multicenter persistent ADHD CollaboraTion (IMpACT). Statistical analyses were divided into 3 steps: (1) gene-level analysis of rare variants (minor allele frequency (MAF)<1\%); (2) single marker association tests of common variants (MAF⩾1\%), with replication of the top signals; and (3) pathway analyses. In total, 9365 individuals (1846 cases and 7519 controls) were examined. Replication of the most associated common variants was attempted in 9847 individuals (2077 cases and 7770 controls) using fixed-effects inverse variance meta-analysis. With a Bonferroni-corrected significance level of 1.82E-06, our analyses of rare coding variants revealed four study-wide significant loci: 6q22.1 locus (P=4.46E-08), where NT5DC1 and COL10A1 reside; the SEC23IP locus (P=6.47E-07); the PSD locus (P=7.58E-08) and ZCCHC4 locus (P=1.79E-06). No genome-wide significant association was observed among the common variants. The strongest signal was noted at rs9325032 in PPP2R2B (odds ratio=0.81, P=1.61E-05). Taken together, our data add to the growing evidence of general signal transduction molecules (NT5DC1, PSD, SEC23IP and ZCCHC4) having an important role in the etiology of ADHD. Although the biological implications of these findings need to be further explored, they highlight the possible role of cellular communication as a potential core component in the development of both adult and childhood forms of ADHD.},
  language  = {en}
}