title: Severity but not comorbidities predicts response to methylphenidate in adults with attention-deficit/hyperactivity disorder: results from a naturalistic study.
abstract: Although the identification of reliable predictors of methylphenidate response in adults with attention-deficit/hyperactivity disorder (ADHD) is necessary to guide treatment decisions, very few data exist on this issue. Here, we assessed the predictors of clinical response to immediate-release methylphenidate hydrochloride (IR-MPH) in a naturalistic setting by analyzing the influence of demographic factors, severity, and a wide range of comorbid psychiatric disorders. Two hundred fifty adult patients with ADHD were evaluated and completed a short-term treatment with IR-MPH. Mental health diagnoses were based on Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria through the use of standard structured interviews. The Swanson, Nolan, and Pelham Rating Scale, version 4, adapted to adults was used to assess the severity of ADHD. In the linear regression model, only higher severity of ADHD was associated to a better IR-MPH response (b = 0.770; P < 0.001). Treatment of comorbidities in a subsample (n = 62) did not modify this pattern. Our findings suggest that in clinical settings, patients with more severe ADHD symptoms have a good response to treatment independently from the presence of mild or stabilized comorbidities and their treatments. For adults with ADHD, differently from other common psychiatric disorders such as depression and anxiety, higher severity is associated with better treatment response.
authors.affiliation: From the *ADHD Outpatient Clinic, Hospital de Clínicas de Porto Alegre, and †Department of Genetics, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Rio Grande do Sul; ‡Postgraduate Program in Biotechnology, Centro Universitário UNIVATES, Lajeado; §Department of Psychiatry, Faculdade de Medicina, Universidade Federal do Rio Grande do Sul, Rio Grande do Sul; and ||National Institute of Development Psychiatry for Children and Adolescents, São Paulo, Brazil.
authors.forename: Marcelo M
authors.initials: MM
authors.lastname: Victor
authors.forename: Diego L
authors.initials: DL
authors.lastname: Rovaris
authors.forename: Carlos A I
authors.initials: CA
authors.lastname: Salgado
authors.forename: Katiane L
authors.initials: KL
authors.lastname: Silva
authors.forename: Rafael G
authors.initials: RG
authors.lastname: Karam
authors.forename: Eduardo S
authors.initials: ES
authors.lastname: Vitola
authors.forename: Felipe A
authors.initials: FA
authors.lastname: Picon
authors.forename: Verônica
authors.initials: V
authors.lastname: Contini
authors.forename: Paula O
authors.initials: PO
authors.lastname: Guimarães-da-Silva
authors.forename: Paula
authors.initials: P
authors.lastname: Blaya-Rocha
authors.forename: Paulo S
authors.initials: PS
authors.lastname: Belmonte-de-Abreu
authors.forename: Luis A
authors.initials: LA
authors.lastname: Rohde
authors.forename: Eugenio H
authors.initials: EH
authors.lastname: Grevet
authors.forename: Claiton H D
authors.initials: CH
authors.lastname: Bau
mesh_terms: D000328:Adult; D001289:Attention Deficit Disorder with Hyperactivity / Q000188:drug therapy* / Q000453:epidemiology*; D000697:Central Nervous System Stimulants / Q000627:therapeutic use*; D015897:Comorbidity; D005260:Female; D006801:Humans; D008297:Male; D001523:Mental Disorders / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology*; D008774:Methylphenidate / Q000627:therapeutic use*; D011569:Psychiatric Status Rating Scales; D012720:Severity of Illness Index; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000697:Central Nervous System Stimulants; D008774:Methylphenidate