A randomized controlled multicenter trial on the multimodal treatment of adult attention-deficit hyperactivity disorder: enrollment and characteristics of the study sample.

Adult ADHD is a frequent psychiatric disorder affecting relevant aspects of an individual's life. The aim of our study group was to carry out the first randomized controlled multicenter study to evaluate the effects of psychotherapy compared to clinical management in combination with psychopharmacological treatment with methylphenidate (MPH) or placebo (Plac) in a factorial four-arm design. Here, we present the enrollment procedure and description of adult ADHD patients recruited for the trial. Four hundred and thirty-three adult patients with ADHD were randomized at seven study sites in Germany to four treatment conditions: manualized dialectical-behavioral-therapy-based group psychotherapy (GPT) plus MPH or Plac, or clinical management (CM) including supportive counseling plus MPH or Plac with weekly sessions in the first 12 weeks and monthly sessions thereafter. Assessment for eligibility included standardized scales and instruments. After prescreening of 1,480 patients, 518 were evaluated for trial participation and 433 were randomized. The main reasons for prescreening failure were lack of interest in participating (n = 205), difficulties in meeting the time and effort requirements for participation (n = 186), and contraindications for psychopharmacological treatment with MPH (n = 194). The full analysis set (FAS) comprised 419 adult ADHD patients (mean age 35.2 years, males/females 1:1). Fifty-seven percent of the patients suffered from the combined ADHD subtype. Prevalence of at least one current or lifetime axis-I comorbidity was 66 %. Axis-II comorbidity rates was 18 % (patients with comorbid borderline and antisocial personality disorders were excluded). Our network was able to recruit an adult ADHD sample essentially comparable to community samples. A selection bias was created by excluding patients unable or unwilling to participate, or who had somatic and psychiatric contraindications for stimulant treatment (Current Controlled Trials ISRCTN54096201, FUNDING: Federal Ministry of Education and Research 01GV0606).