title: Symptoms of generalized anxiety disorder but not panic disorder at age 15 years increase the risk of depression at 18 years in the Avon Longitudinal Study of Parents and Children (ALSPAC) cohort study.
abstract: BACKGROUND
  Generalized anxiety disorder (GAD) and panic disorder (PD) differ in their biology and co-morbidities. We hypothesized that GAD but not PD symptoms at the age of 15 years are associated with depression diagnosis at 18 years.
  
  
  METHODS
  Using longitudinal data from the Avon Longitudinal Study of Parents and Children (ALSPAC) birth cohort we examined relationships of GAD and PD symptoms (measured by the Development and Well-Being Assessment) at 15 years with depression at 18 years (by the Clinical Interview Schedule - Revised) using logistic regression. We excluded adolescents already depressed at 15 years and adjusted for social class, maternal education, birth order, gender, alcohol intake and smoking. We repeated these analyses following multiple imputation for missing data.
  
  
  RESULTS
  In the sample with complete data (n = 2835), high and moderate GAD symptoms in adolescents not depressed at 15 years were associated with increased risk of depression at 18 years both in unadjusted analyses and adjusting for PD symptoms at 15 years and the above potential confounders. The adjusted odds ratio (OR) for depression at 18 years in adolescents with high relative to low GAD scores was 5.2 [95% confidence interval (CI) 3.0-9.1, overall p < 0.0001]. There were no associations between PD symptoms and depression at 18 years in any model (high relative to low PD scores, adjusted OR = 1.3, 95% CI 0.3-4.8, overall p = 0.737). Missing data imputation strengthened the relationship of GAD symptoms with depression (high relative to low GAD scores, OR = 6.2, 95% CI 3.9-9.9) but those for PD became weaker.
  
  
  CONCLUSIONS
  Symptoms of GAD but not PD at 15 years are associated with depression at 18 years. Clinicians should be aware that adolescents with GAD symptoms may develop depression.
authors: Centre for Academic Mental Health,School of Social and Community Medicine,University of Bristol,Bristol,UK.
authors: S J C
authors: SJ
authors: Davies
authors: Centre for Academic Mental Health,School of Social and Community Medicine,University of Bristol,Bristol,UK.
authors: R M
authors: RM
authors: Pearson
authors: NHMRC Centre for Research Excellence in Mental Health and Substance Use,National Drug and Alcohol Research Centre,University of New South Wales,Sydney,Australia.
authors: L
authors: L
authors: Stapinski
authors: Centre for Academic Mental Health,School of Social and Community Medicine,University of Bristol,Bristol,UK.
authors: H
authors: H
authors: Bould
authors: Centre for Academic Mental Health,School of Social and Community Medicine,University of Bristol,Bristol,UK.
authors: D M
authors: DM
authors: Christmas
authors: Centre for Academic Mental Health,School of Social and Community Medicine,University of Bristol,Bristol,UK.
authors: K S
authors: KS
authors: Button
authors: Centre for Academic Mental Health,School of Social and Community Medicine,University of Bristol,Bristol,UK.
authors: P
authors: P
authors: Skapinakis
authors: Division of Psychiatry,University College London,London,UK.
authors: G
authors: G
authors: Lewis
authors: Centre for Academic Mental Health,School of Social and Community Medicine,University of Bristol,Bristol,UK.
authors: J
authors: J
authors: Evans
mesh_terms: D000293:Adolescent; D001008:Anxiety Disorders / Q000453:epidemiology*; D015897:Comorbidity; D003866:Depressive Disorder / Q000453:epidemiology*; D004739:England / Q000453:epidemiology; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D016584:Panic Disorder / Q000453:epidemiology*; D012306:Risk
keywords: Adolescents; Avon Longitudinal Study of Parents and Children; anxiety; depression; generalized anxiety disorder