UNCORRECTED PROOF Short communication The TaqIA polymorphism linked to the DRD2 gene is related with lower attention and less inhibitory control in alcoholic patients R. Rodríguez-Jiménez a, *, C. Ávila b , G. Ponce a , M.I. Ibáñez b , G. Rubio c , M.A. Jiménez-Arriero a , I. Ampuero d , J.A. Ramos d , J. Hoenicka a , T. Palomo a a Unidad de Conductas Adictivas (UCA), Servicio de Psiquiatría, Hospital Universitario 12 de Octubre, Avda. de Córdoba s/n, 28041 Madrid, Spain b Dpto. Psicología Básica, Clínica y Psicobiología, Universitat Jaume I, Castelló, Spain c Servicios de Salud Mental, Retiro, Madrid, Spain d Facultad de Medicina, Universidad Complutense Madrid, Madrid, Spain Received 1 February 2005; accepted 30 May 2005 Abstract The TaqIA polymorphism linked to the DRD2 gene has been associated with alcoholism. The aim of this work is to study attention and inhibitory control as per the continuous performance test and the stop task in a sample of 50 Spanish male alcoholic patients split into two groups according to the presence of the TaqIA1 allele in their genotype. Our results show that alcoholics carrying the TaqIA1 allele present lower sustained attention and less inhibitory control than those patients without such allele. © 2005 Published by Elsevier SAS. Keywords: Alcoholism; TaqIA polymorphism; CPT; Stop task; Attention; Inhibitory control 1. Introduction Various genetic association studies have shown that a num- ber of genetic polymorphisms might be linked to alcoholism. Blum et al. [1] reported the first association between a gene variant and alcoholism, specifically that of the TaqIA poly- morphism linked to DRD2 gene. This polymorphism con- sists of a single nucleotide polymorphism (SNP) localising to the 3′UTR of the DRD2 gene, and a significant relation- ship has been found to exist between the TaqIA1 allele in alcoholics of Caucasian populations relative to controls [2]. A number of phenotypes have been reported in relation to the TaqIA1allele, such as low density of the D2 dopaminer- gic receptor in the striatum and nucleus accumbens [3–5],a lower rate of brain glucose consumption [6], abnormalities in the P300 wave [7–9], higher density of the dopamine trans- porter [10], higher levels of urine homovanillic acid [11], lower global impulsiveness as evaluated with the Barrat impul- siveness scale (BIS) [12], and high prevalence of antisocial personality disorder [13]. Furthermore, the TaqIA1 allele has also been linked to the attention-deficit hyperactivity disorder (ADHD) [14], which is characterised by neuropsychological alterations such as attention-deficit and poor inhibitory control [15]. We have investigated the hypothesis that lower attention and less inhibitory control in alcoholics could be related to the TaqIA1 allele. This is, to the best of our knowledge, the first study of its kind evaluating the relationship between these two neuropsychological variables and the TaqIA polymor- phism in alcoholics. 2. Subjects and methods 2.1. Subjects Our sample was comprised of 50 Spanish males with an intelligence quotient (IQ) above 70 recruited consecutively from the general hospital and outpatient clinics that fulfilled criteria of alcohol dependence. All patients were, at last, second-generation Spaniards. In order to assess substance * Corresponding author. Tel.: +34 91 390 8022; fax: +34 91 390 8538. E-mail address: mjimenez.hdoc@salud.madrid.org (R. Rodríguez-Jiménez). ARTICLE IN PRESS European Psychiatry "" (2005) """-""" http://france.elsevier.com/direct/EURPSY/ 0924-9338/$ - see front matter © 2005 Published by Elsevier SAS. doi:10.1016/j.eurpsy.2005.05.010 EURPSY-2363 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56