Long-Term Outcomes of Attention-Deficit/Hyperactivity Disorder and Conduct Disorder: A Systematic Review and Meta-Analysis.
Attention-deficit/hyperactivity disorder (ADHD) and conduct disorder (CD) are common externalizing disorders. Despite previous research demonstrating that both are longitudinally associated with adverse outcomes, there have been no systematic reviews examining all of the available evidence linking ADHD and CD with a range of health and psychosocial outcomes.



Electronic databases (EMBASE, Medline, and PsycINFO) were searched for studies published from 1980 up to March 2015. Published cohort and case-control studies were included if they reported a longitudinal association between ADHD or CD and adverse outcomes with a minimum follow-up of 2 years. Outcomes with sufficient data were pooled in a random effects meta-analysis to give overall odds ratios (ORs) with corresponding 95% CIs.



Of the 278 studies assessed, 114 met inclusion criteria and 98 were used in subsequent meta-analyses. ADHD was associated with adverse outcomes including academic achievement (e.g. failure to complete high school; odds ratio [OR] = 3.7, 95% CIs 2.0-7.0), other mental and substance use disorders (e.g. depression; OR = 2.3, 1.5-3.7), criminality (e.g. arrest; OR = 2.4, 1.5-3.8), and employment (e.g., unemployment; OR = 2.0, 1.0-3.9). CD was associated with outcomes relating to academic achievement (e.g. failure to complete high school; OR = 2.7, 1.5-4.7), other mental and substance use disorders (e.g., illicit drug use; OR = 2.1, 1.7-2.6), and criminality (e.g. violence; OR = 3.5, 2.3-5.3).



This study demonstrated that ADHD and CD are associated with disability beyond immediate health loss. Although the analyses could not determine the mechanisms behind these longitudinal associations, they demonstrate the importance of addressing ADHD and CD early in life so as to potentially avert a wide range of future adverse outcomes.
School of Public Health, University of Queensland, Herston, Queensland, Australia; Queensland Centre for Mental Health Research, The Park Centre for Mental Health, Wacol, Queensland; and Institute for Health Metrics and Evaluation, University of Washington, Seattle; University of Queensland Centre for Clinical Research, Herston, Queensland. Electronic address: holly_erskine@qcmhr.uq.edu.au.
Holly E
HE
Erskine
Institute of Health and Biomedical Innovation and School of Public Health and Social Work, Queensland University of Technology, Kelvin Grove, Queensland.
Rosana E
RE
Norman
School of Public Health, University of Queensland, Herston, Queensland, Australia; Queensland Centre for Mental Health Research, The Park Centre for Mental Health, Wacol, Queensland; and Institute for Health Metrics and Evaluation, University of Washington, Seattle.
Alize J
AJ
Ferrari
Centre for Youth Substance Abuse Research, The University of Queensland.
Gary C K
GC
Chan
Duke University Medical Center, Durham, NC.
William E
WE
Copeland
School of Public Health, University of Queensland, Herston, Queensland, Australia; Queensland Centre for Mental Health Research, The Park Centre for Mental Health, Wacol, Queensland; and Institute for Health Metrics and Evaluation, University of Washington, Seattle.
Harvey A
HA
Whiteford
Queensland Centre for Mental Health Research, The Park Centre for Mental Health, Wacol, Queensland; The University of Queensland Centre for Clinical Research, Herston, Queensland; and Metro North Mental Health, Royal Brisbane and Women's Hospital, Herston, Queensland.
James G
JG
Scott
D001289:Attention Deficit Disorder with Hyperactivity / Q000523:psychology* / Q000628:therapy; D016022:Case-Control Studies; D015331:Cohort Studies; D019955:Conduct Disorder / Q000523:psychology* / Q000628:therapy; D016208:Databases, Factual; D006801:Humans; D008137:Longitudinal Studies; D016896:Treatment Outcome
attention-deficit/hyperactivity disorder; conduct disorder; epidemiology; longitudinal; outcomes