17.1.1 Diagnostic studies – Do the phenomena of hyperactivity, inattention and impulsiveness cluster together?
Characteristics of Included Studies
Reference / Type of study / Quality assessment / Population (characteristics) / Factors / Do the phenomena cluster together? / Measure(s) / FundingAMADOR-CAMPOS2005 / FACTOR ANALYSIS / 1.1 Well covered
1.2 Well covered / n= 1018 school-aged children / Confirmatory factor analysis showed a three factor model (83.2% of total variance):
Inattention
Hyperactivity
Impulsivity
And a two factor model (79.3% of total variance):
Inattention
Hyperactivity-impulsivity / Hyperactivity and inattentiveness represent separate symptom dimensions in this sample. / DSM-IV symptom list / Grant BSO 2001-3751-C02-01 from Ministerio de Ciencia y Tecnologia (Spain) and from the Agencia d’Ajuts Universitaris I de Recerca Generalitat de Catalunya 2002, SGF00153
BAUERMEISTER 1992 / FACTOR ANALYSIS / 1.1 Well covered
1.2 Not addressed / 2 samples:
n= 665 (aged 4-5) (preschool children)
& n= 680 (aged 6-13) (school children)
All Puerto Rican children identified by teachers as requiring referral to psycho-educational services (for e.g. learning difficulties, behavioural or emotional problems) / For age 4-5 sample: 2 factors (attention deficit/hyperactivity & oppositional defiant)
For age 6-13 sample : 3 factors (hyperactivity/impulsivity; inattention/distractibility & oppositional defiant) / In preschool children the phenomena all cluster together, in school children it appears there are two clusters of symptoms: hyperactive/impulsive and inattentive. / Teacher-rated: 14 ADHD items and 9 ODD items based closely on DSM-III-R symptoms / University of Puerto Rico Institutional Research Fund
CONNERS1969 / FACTOR ANALYSIS / 1.1 Well covered
1.2 Adequately addressed / n= 103; mean age: 9.8 years
Children with behaviour disorders, hyperactivity or poor attention spans associated with learning disorders. For all included children drug therapy seemed specifically indicated. / 5 factors:
Defiance or aggressive conduct disorder
Day-dreaming or inattentive
Anxious-fearful
Hyperactivity
[poorly defined fifth factor] ‘health’ / Hyperactivity and inattentiveness represent separate symptom dimensions in this sample Although both sets of symptoms improved when children administered dextroamphetamine sulphate. / Teacher-rated: Conners Teacher rating Scale / Public Health Service grant & Research Scientist Development award, both from NIMH.
NB. Smith, Kline & French Laboratories
CONNERS1997 / FACTOR ANALYSIS / 1.1 Well covered
1.2 Adequate / 172 adolescents
86 ADHD
86 controls
(12-17 yrs) / 6 factors:
Family problems
Emotional problems
Conduct problems
Cognitive problems
Anger control problems
Hyperactivity / Hyperactivity was the only phenomena of the clinical question reported / Conners’-Wells Adolescent Self Report / Senior Research Scientist Award (partial)
CONNERS1998 / FACTOR ANALYSIS / 1.1 Well covered
1.2 Adequate / 182 children
91 ADHD
91 controls
(3-17yrs)
Mean age 10.16(3.40) / 7 factors:
Cognitive problems
Oppositional
Hyperactivity/Imp
Anxious-shy
Perfectionism
Social problems
Psychosomatic / Hyperactivity and impulsivity cluster together into one factor / Revised Conners’ Parent Rating Scale / NIMH grant (partial)
DREGER1964 / FACTOR ANALYSIS / 1.1 Adequate
1.2 Adequate / 351 clinical sample
80 control sample / 10 factors:
Paranoid/aggressive
Antisocial aggressive
Intellectual retardation
Psychoid desurgency
Confident/sociable
Impulsive/hyperactive
Sadistic aggressive
Disturbed sleep
Immaturity
Parental age / Hyperactivity and impulsivity form part of one dimension / Behavioural Classification Project (parent response) / NIMH Florida Council on Research & Training in Mental Health
GLUTTING2005 / FACTOR ANALYSIS / 1.1 Adequate
1.2 Adequate / 1080 college students (m=18.7 yrs) and parent / 3 factors:
Inattentiveness
Hyperactivity
Impulsivity / Inattentiveness, hyperactivity and impulsivity formed separate dimensions / Student Response Inventory
Parent Response Inventory / NR
GOMEZ1999 / FACTOR ANALYSIS / 1.1 Well covered
1.2 Adequate / n= 1275 (age: 5-11 years; non-clinical, sampled from schools). / 3 factors:
Inattention
Hyperactivity
Impulsivity
For both parent and teacher ratings all 3 factors were significantly (p < .001) correlated with each other (correlations ranged from 0.50 - 0.89)
NB. Fit of 3-factor model only marginally better than a 2-factor model / Although the three phenomena of hyperactivity, impulsivity and inattentiveness appear to represent separate dimensions of ADHD symptoms, they were all significantly correlated, indicating they share a proportion of their variance / Parent- and Teacher-rated: DSM-IV ADHD rating scale / NR
HO1996 / FACTOR ANALYSIS / 1.1 Adequate
1.2 Well covered / 3069 primary school children(Hong Kong)
(6 to 7 yrs) / 3 factors:
Hyperactive
Antisocial
Neurotic / Rutter’s Child Behaviour Questionnaires (parent + teachers) / The Croucher Foundation
HUDZIAK1998 / FACTOR ANALYSIS
Latent class analysis / 1.1 Well covered
1.2 Adequate / Sample of adolescent, female twin-pairs (non-clinical, sampled from birth records)
n= 1549 twin-pairs (aged 13-19) / 2 factors:
Inattention
Hyperactivity/Impulsivity
Latent class analysis revealed ADHD symptoms are best conceptualised as 3 continuous symptom domains: IA, H/I and IA + H/I (consistent with correlation between IA and H/I in factor analysis / While inattention, and hyperactivity/impulsivity represent 2 separate dimensions of ADHD, they can exist as a ‘combined’ type, and are moderately correlated symptom dimensions / Parent-rated: Clinical interview based on DSM-IV symptom list for ADHD (Responses based on each twin as a child, prior to age 7) / Grants from NIMH; NIAAA & NIMH MH
KOOIJ2005 / FACTOR ANALYSIS / 1.1 Adequately covered
1.2 Well covered / n = 1813 adults; aged 18-75; non-clinical (sampled from GP registers) / 3 factors:
Inattention
Hyperactivity
Impulsivity / Although the 3 phenomena of hyperactivity, impulsivity and inattentiveness appear to represent separate dimensions of symptoms, there were moderate correlations (0.47-0.57) between them, indicating they share a proportion of their variance / Self-report: 23-item Dutch version of ADHD DSM-IV rating scale (all items asked about current ADHD symptoms) / Mental Health Institute GCZ Delfland; Health Care Insurance Compnay DSW; Parnassia, psycho-meidacl centre; and partky from grants from NIMH and NARSAD
NB. 2 authors are consultants to and at speakers bureau for Janen-Cilag and Eli Lilly and Company, 1 author has served as consultant to Abbott, and 1 author is consultant to GlaxoSmithKlien
LAHEY1988 / FACTOR ANALYSIS / 1.1 Well covered
1.2 Adequate / 2 samples:
n= 667 (aged: ‘elementary school’; non-referred children)
& n=86 (aged: 6-13; consecutively clinic-referred for psychological assessment (48% ADD/H; 22% ADD/WO) / SNAP checklist: 2 factors (same for both samples): Inattention/Disorganisation
Hhyperactivity/Impulsivity
Clinician rated scale: 3 factors:
Hyperactivity/Inattention Inattention/Disorganisation ‘Sluggish tempo’ / In both samples, and for both teacher-rated and clinician-rated scales, hyperactivity and impulsivity cluster together, and both cluster separately from inattention symptoms / Teacher-rated: SNAP checklist (16-items from DSM-III symptom list)
& Clinician-rated: 20-items from DSM-III symptoms (for clinic-referred sample only) / NR
LAHEY1994 / FACTOR ANALYSIS / 1.1 Well covered
1.2 Adequate / 380 clinic referred youths
(4 to 17 yrs) / NA / 3 subtypes of attention deficit hyperactivity disorder (predominantly inattentive, predominantly hyperactive-impulsive, and combined types) were distinguished on the basis of the degree of deviance on separate dimensions of inattention and hyperactivity-impulsivity. These three subtypes were found to differ in terms of types of impairment, age, and sex ratio, but not ethnicity. / DSM-IV
(Diagnostic Interview Schedule for Children; parent or teacher)
Children’s Global Assessment Scale / NIMH grant
LEVITON1993 / FACTOR ANALYSIS / 1.1 Well covered
1.2 Not addressed / n= 3451 (all Caucasian, all 8-9 yrs old)
Girls and Boys’ data analysed separately / Girls: 6 factors:
Arithmetic
Hyperactive
Tasks
Read
Daydream
Directions
Boys: 5 factors:
Arithmetic
Hyperactive
Tasks
Read
Daydream / In both female and male samples hyperactivity symptoms and ‘daydream’ symptoms (such as ‘easily distracted’ - similar to ‘inattention’ symptoms from other studies) represent different dimensions of symptoms. / Teacher-rated: Boston Teacher Questionnaire / Program-Project Grant; Children’s Hospital Medical Centre Mental Retardation and Human Development Program; NICHD; NINDS; NINCDS
MCGEE1985 / FACTOR ANALYSIS / 1.1 Well covered
1.2 Well covered / n= 951 children
(7 years of age) / Three main factors:
Aggressiveness
Hyperactivity
Anxiety-fearfulness / NA / Rutter Child Scale B / None
MOLINA2001 / FACTOR ANALYSIS / 1.1 Well covered
1.2 Well covered / 247 (6th, 7th & 8th grades)
(11 to 16 yrs) / 3 factors:
Inattention
Hyperactivity/Imp
Defiant behaviour / 3 factors separate but correlated / Teacher reports of DSM-IV / National Institute of Alcohol and Alcoholism
Uni of Pittsburg
Dep of Psychiatry
National Institute on Drug Abuse
NIMH
PELHAM1992 / FACTOR ANALYSIS / 1.1 Adequate
1.2 Well covered / 931 boys
(5 to 14 yrs) / 3 factors:
Oppositional/Defiant
Inattention
Impulsivity/Overactivity / Impulsivity and overactivity form one dimension / DBD / NIAAA, NIDA
PILLOW1998 / FACTOR ANALYSIS / 1.1 Well covered
1.2 Not addressed / n= 282; all boys; aged 5-15 (mean 9.23)
94% met criteria for ADHD (DSM-III-R); 35%: ODD, and 37% CD. / 3 factors:
Inattention
Hyperactivity
Impulsivity
However, when ADHD symptom items were FA’d with ODD and CD items hyperactivity and impulsivity became one factor, with inattention, ODD and CD factors also. NB. Authors argue this is more clinically relevant model due to high rates of comorbidity of CD and ODD with ADHD. / For ADHD symptoms in isolation: While Inattention; Hyperactivity & Impulsivity represent different dimensions of ADHD symptoms, hyperactivity and impulsivity were highly correlated (0.82), and inattention & impulsivity, and inattention and hyperactivity were also correlated (0.61; 0.59, resp.) / Parent-rated: Disruptive Behaviour Disorders Scale with 6 items from the SNAP added (42-items total; but only 31 items used in FA). / NR
SMITH2000 / FACTOR ANALYSIS / 1.1 Well covered
1.2 Not addressed / n=317
Average age 19.69 years (all undergraduate college students) / 2 primary factors:
Hyperactivity/ impulsivity & Inattention. / Hyperactivity and impulsiveness cluster together, no evidence reported to suggest that inattention clusters with other factors. / Self-report: Adult Behaviour Checklist-Revised (for college sample) / NR
TAYLOR1984 / FACTOR ANALYSIS / 1.1 Adequate
1.2 Adequate / 437 primary school-aged children (6 to 9 yrs)
76 ADHD/CD outpatients
22 CD sample / 7 factors:
Conduct problems
Anxiety
Hyperactivity/Inattention
Unpopularity
Antisocial conduct
Isolation
Oversensitive / Hyperactivity and inattention form one dimension / CTRS / NR
WERRY1975 / FACTOR ANALYSIS / 1.1 Adequate
1.2 Adequate / 291 controls (US)
48 hyperactive (US)
16 hyperactive (NZ)
(elementary school) / 4 factors:
Conduct problems
Hyperactivity/Inattentiveness
Unsociability
Tension/anxiety / Hyperactivity and inattentiveness form one dimension / CTRS / NIMH, MRC
WOLRAICH1996 / FACTOR ANALYSIS / 1.1 Adequate
1.2 Well covered / 8258 children (5th grade in kindergarten) / 5 factors:
Oppositional-defiance
Inattention
Hyperactivity/Impulsivity
Anxiety-depression
Stealing/Truancy / Hyperactivity and impulsivity form one dimension. Another dimension is inattention / Custom (modified from SNAP and DBD) / The United Way
ZUDDAS2006 / FACTOR ANALYSIS / 1.1 Well covered
1.2 Well covered / Primary school-aged children (Italy)
1575 parent reports
1085 teacher reports / 4 factors (both by teacher and parent reports):
Inattention
Hyperactivity/Imp
ODD
CD / Construct validity of ADHD, ODD and CD should also be distinguished from each other / Disruptive Behaviors Disorders Rating Scale / Telethon-Italy Grant
Sardinian Public Health Secretariat Grant
DUPAUL2001 / CROSS-SECTIONAL / NA / 94 children
58 w ADHD
36 controls / NA / NA / NA / DR Pool Healthcare Trust grant