Attention deficit hyperactivity disorder (ADH/D) is a neuropsychological developmental disorder characterized by pervasive and impairing symptoms of inattention, hyperactivity, and impulsivity. Whereas it is well known in children, there is still little information about ADH/D in adults, including prevalence. Indeed, there are actually no epidemiological studies in France, despite the considerable impact of this disorder in a patient's professional and affective life. Moreover, ADH/D rarely stays isolated, and many comorbidities often complicate the diagnostic investigation. It is well known that the so-called ADH/D is composed of two main categories of symptoms (Attentional Disorder/Hyperactiviy Disorder), but Impulsiveness also remains a major symptom. Objective. - The aim of this study was to evaluate not only the prevalence of Impulse Control Disorders (ICD) but also psychological and addictive comorbidities among adult patients with ADH/D. A total of 100 patients from specialized consultations of adult ADH/D were evaluated in this study, but only 81 were included after presenting all the clinical criteria of ADH/D. Method. - We used the DSM IV-T-R for ADH/D, the Minnesota Impulsive Disorders Interview a semi-structured clinical interview assessing impulse control disorders (ICD) (compulsive buying, trichotillomania, compulsive sexual behaviour, kleptomania, pyromania and intermittent explosive disorder), and the Mini International Neuropsychiatric Interview in order to evaluate psychiatric and addictive comorbidities. Results. - More than 90 % of the patients met the early apparition criteria of ADH/D (before 7 years). More than half of the patients presented a mixed type of ADH/D (both inattentive and hyperactive impulsive forms): 55.6 % vs 44.4 % for the inattentive type. The vast majority of patients showed a complete form (with a total of 6 or more symptoms out of 9, of inattentive and/or impulsive-hyperactivity category): 93.8 % and only 6.2 % presented a sub-syndromic form of ADH/D (with 3 symptoms at least of one and/or the other category). Regarding the ICDs, we found a proportion of 66 % of patients manifesting at least one, the most frequent ICD being the Intermittent Explosive Disorder (IED): 29.6 %, followed by Compulsive Buying (CB): 23.4 %, Pathological Gambling (PG): 7.4 %, Kleptomania and Compulsive Sexual Behaviour: 2.4 %, and Trichotillomania: 1.2 %. Among the psychiatric comorbidities evaluated, generalized anxiety disorder: 61.7 %, followed by dysthymia: 44.4 %, major depressive episode: 28.3 %, Agoraphobia: 22.2 %, panic disorder: 17.2 %, hypomanic episode: 16 %, social phobia: 11.1 %, bulimia nervosa: 8.6 %, and antisocial personality disorder and obsessive-compulsive disorder: 3.7 %. Regarding the addictive comorbidities, we found a prevalence of 14.8 % of substance abuse (non-alcohol), followed by 7.4 % of alcohol abuse, 6.1 % of substance dependence (non-alcohol), and 3.7 % of alcohol dependence. Conclusion. - ADH/D in adults continues to be unrecognized in France. The aim of this study was to evaluate the prevalence of impulse control disorders, psychiatric and addictive comorbidities in adults with ADH/D. The results enable us to appreciate quantitative and qualitative data for 81 French adults with ADH/D. This disorder rarely remains isolated and is often associated with many others, especially anxiety and mood disorders. We also observed that impulsivity stays at the heart of the ADH/D, either through impulsive behaviours or addictive disorders. Considering the lack of studies with ADH/D adults, it is difficult to compare our data. The diagnosis of ADH/D is complex and stays controversial, moreover the strong prevalence of comorbidities points out the importance of differential diagnosis. (C) L'Encephale, Paris, 2015.