17.1.6 Diagnostic studies – Is there evidence for a consistent heritability, neurobiological, (or other) associations suggesting causality?

Characteristics of Included Studies

Reference / Type of study / Quality assessment / No. of studies / Characteristics of studies / Aim / Outcome measures / Results / Funding
BOONSTRA2005 / REVIEW
Meta-analysis / 1.1 Well covered
1.2 Well covered
1.3 Well covered
1.4 Not addressed
1.5 Not addressed
2.1 + / 13 studies / Executive functioning in adults / Compared neuropsychological executive functioning and non-executive functioning between adults with ADHD and controls / EF:
COWAT
CPT
WAIS
Stroop
Trailmaking Test / Effect size
Executive functioning:
verbal fluency (d=0.62)
inhibition (d=0.64 and d=0.89)
set shifting (d=0.65)
Non-executive functioning:
consistency of response (d=0.57)
word reading (d=0.60)
colour naming (d=0.62) / NR
DICKSTEIN2006 / Review
Meta-analysis / 1.1 Well covered
1.2 Well covered
1.3 Well covered
1.4 Not reported
1.5 Adequate
2.1 + / 16 studies / Functional neuroimaging studies / Analysed neuroimaging studies comparing neural activity in people with ADHD and healthy controls / fMRI
FMRI
PET / Frontal activity was found in people with ADHD across studies / NIMH
FARAONE2005 / REVIEW / 1.1 Well covered
1.2 Adequate
1.3 Adequate
1.4 Not addressed
1.5 Not addressed
2.1 + / 20 studies / Twin studies / Examine evidence showing that ADHD is strongly influenced by genes and review the progress of molecular genetic studies seeking to find these genes and the variants that increase susceptibility to ADHD / various / Both genetic and nongenetic factors contribute to the development of ADHD / National Institute of Health
HERVEY2004 / REVIEW
Meta-analysis / 1.1 Well covered
1.2 Well covered
1.3 Well covered
1.4 Not addressed
1.5 Not reported
2.1 + / 33 studies / 18+ adults with ADHD / Reviews studies assessing neuropsychological performance in adults with ADHD / DSMs
Wender-Utah
Various neuropsychological tests / Neuropsychological deficits are expressed in ADHD adults, impairments in (ES):
attention: medium range (d, 0.15-0.83)
behavioural inhibition (d, 0.05-0.85)
memory (d, 0.01-0.90) / NR
KLEIN2006 / CROSS SECTIONAL / NA / 57 w ADHD
53 controls / NA / NA / NA / NA / NR
LI2006 / REVIEW
Meta-analysis / 1.1 Well covered
1.2 Well covered
1.3 Well covered
1.4 Not reported
1.5 Well covered
2.1 + / 36 DAT1
50 DRD4
13 DRD5 / Molecular genetic studies of ADHD / Investigate the role of 3 dopamine-related genes / A statistically significant association between ADHD and dopamine system genes (especially DRD4 and DRD5) / Grants the Ministry of Education , PRC, the National Natural Science Foundation of China and the Shanghai Municipal Commission for Science and Technology
LINNET2003 / REVIEW / 1.1 Well covered
1.2 Well covered
1.3 Well covered
1.4 Not reported
1.5 Well covered
2.1 ++ / 24 studies (tobacco smoking)
9 studies (alcohol)
1 study (caffeine)
5 studies
(psychosocial stress) / Pregnant women use of substances and psychosocial stress and the effects on their children / Examined the associations of common lifestyle factors during pregnancy such as smoking tobacco, alcohol and caffeine use, and maternal psychological stress to the development of ADHD and ADHD-like symptoms in children. / CBCL
SDQ
Rutter’s quest / Studies on tobacco use indicated a greater risk of ADHD-related disorders among children whose mothers smoked during pregnancy.
Contradictory findings were reported in the alcohol studies.
No conclusions were reached on the basis of one caffeine study.
Inconsistent results were found from the psychological stress studies but indicated a modest contribution to ADHD in the offspring. / Nordic Council of Ministers research program Longitudinal epidem
SCHOELIN2005 / REVIEW
Meta-analysis / 1.1 Well covered
1.2 Well covered
1.3 Well covered
1.4 Adequate
1.5 Well covered
2.1 ++ / 24 studies
867 patients
806 controls / Clinically diagnosed ADHD adult patients (16+ yrs) / Reviews quantitatively the neuropsychological data in adults with ADHD by categorising each neuropsy measure into 1 of 10 neuropsy functional domains. / ADHD (DSM-III-R or DSM-IV)
Neuropsych
Functional domains:
Verbal intelligence
Executive functions
Fluency
Visual-figural problem solving
Abstract problem solving; working memory
Simple attention
Sustained attention
Focused attention
Verbal memory
Figural memory / Pooled weighted ES
Verbal intelligence d=-.27
Executive functions d= -.21
Fluency d=-.52
Visual-figural problem solving
d=-.26
Abstract problem solving; working memory d=-.51
Simple attention d=-.38
Sustained attention d=-.52
Focused attention d=-.55
Verbal memory d=-.56
Figural memory d=-.18 / NR
WILLCUTT2005 / REVIEW
Meta-analysis / 1.1 Well covered
1.2 Well covered
1.3 Well covered
1.4 Not addressed
1.5 Adequate
2.1 + / 83 studies
3734 ADHD
2969 control / ADHD studies measuring EF / Reviews the theory of executive function of ADHD / ADHD: DSM-III, DSM-III-R, DSM-IV & ICD-10
EF constructs:
response inhibition, vigilance, set-shifting, planning, organisation, verbal working memory & spatial working memory / Groups with ADHD exhibited significant impairment on all EF tasks.
ES for all measures fell in the medium range (.46-.69) but strongest and most consistent effects were obtained on measures of response inhibition, vigilance, working memory, and planning / National Inst of Health Grant (partial)
WOODS2002 / REVIEW / 1.1 Well covered
1.2 Well covered
1.3 Adequate
1.4 Poor
1.5 Adequate
2.1 + / 35 studies / Studies that specifically examined the neurocognitive functioning of adults w ADHD / Reviewing the usefulness of neuropsychological procedures in differentiating adults with ADHD from various clinical and control populations. / Neuropsychological measures / Adults with ADHD demonstrate subtle impairments on select measures of attention and executive functions, auditory-verbal list learning and complex information processing speed relative to normal controls. / NR

Characteristics of Excluded Studies

Reference / Type of Study / Reason for Exclusion
DIMAIO2003 / REVIEW / Poor quality (description of the methodology is scarce)
YEH2004 / REVIEW / Poor quality (description of the methodology is scarce)