title: Co-occurring symptoms of attention deficit hyperactivity disorder (ADHD) in a population-based sample of adolescents screened for depression.
abstract: BACKGROUND
  Depression is common in adolescents, with a gender bias towards girls. Symptoms associated with attention deficit hyperactivity disorder (ADHD) tend to co-occur in depressed adolescents. This may be related to common features between the two symptom domains, but co-occurring ADHD symptoms may also inflate the severity of depression. The present study investigates the frequency and influence of ADHD symptoms co-occurring with depression in a gender balanced population-based sample of Norwegian adolescents.
  
  
  METHODS
  A sample of 9614 adolescents (16-19 years) completed a questionnaire including the short version of the Mood and Feelings Questionnaire (sMFQ) and the Adult ADHD Self-Report Scale (ASRS), with items reflecting symptoms associated with depression and ADHD, respectively. The sMFQ sum score was used as a proxy for severity of depression, and adolescents with a score equal to or above the 90th percentile were defined as depressed. A high response on any of the ASRS items was used to define the presence of an ADHD symptom, and the number of high scores was used to indicate severity.
  
  
  RESULTS
  ADHD symptoms were frequently reported by the adolescents, with a higher frequency in girls than in boys. The gender differences were, however, minor when the analysis was restricted to the adolescents defined as depressed. Each severe symptom reported on the ASRS contributed significantly to increase the sum score on the sMFQ, and more than 20 % of the adolescents defined as depressed reported six or more symptoms within the ASRS inattention subscale.
  
  
  CONCLUSIONS
  The results emphasize the importance of screening for symptoms associated with ADHD when assessing adolescents presenting symptoms indicating depression. Although girls reported higher frequency of symptoms within both domains, the gender bias was dependent on the overall symptom severity. Awareness of co-occurrence of symptoms and gender biases are of importance for both clinical work and future research on mental health and service use in adolescence.
authors.affiliation: Department of Biological and Medical Psychology, Jonas Lies vei 91, Bergen, Norway. astri.lundervold@psych.uib.no.|Regional Centre for Child and Youth Mental Health and Child Welfare, Uni Research, Bergen, 5002, Norway. astri.lundervold@psych.uib.no.|K. G. Jebsen Center for Research on Neuropsychiatric Disorders, University of Bergen, Bergen, 5009, Norway. astri.lundervold@psych.uib.no.
authors.forename: Astri J
authors.initials: AJ
authors.lastname: Lundervold
authors.affiliation: Department of Psychology, University of California, Berkeley, CA, USA. stephen.hinshaw@gmail.com.|Department of Psychiatry, University of California, San Francisco, CA, USA. stephen.hinshaw@gmail.com.
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Hinshaw
authors.affiliation: Department of Biological and Medical Psychology, Jonas Lies vei 91, Bergen, Norway. lin.sorensen@psych.uib.no.|K. G. Jebsen Center for Research on Neuropsychiatric Disorders, University of Bergen, Bergen, 5009, Norway. lin.sorensen@psych.uib.no.
authors.forename: Lin
authors.initials: L
authors.lastname: Sørensen
authors.affiliation: Regional Centre for Child and Youth Mental Health and Child Welfare, Uni Research, Bergen, 5002, Norway. maj-britt.posserud@uni.no.|Department of Child and Adolescent Psychiatry, Haukeland University Hospital, Bergen, Norway. maj-britt.posserud@uni.no.|Department of Clinical Medicine, Faculty of Medicine and Dentistry, University of Bergen, Norway. maj-britt.posserud@uni.no.
authors.forename: Maj-Britt
authors.initials: MB
authors.lastname: Posserud
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior / Q000523:psychology*; D001289:Attention Deficit Disorder with Hyperactivity / Q000453:epidemiology* / Q000523:psychology; D015897:Comorbidity; D003863:Depression / Q000175:diagnosis* / Q000453:epidemiology* / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008603:Mental Health; D009664:Norway; D012727:Sex Characteristics; D012737:Sex Factors; D011795:Surveys and Questionnaires