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A longitudinal investigation of cognitive functioning and its relationship to symptom severity and academic functioning in treatment seeking youth with ADHD

Pia Tallberg
Pia Tallberg
, 
Maria Rastam
Maria Rastam
, 
Sean Perrin
Sean Perrin
, 
Anne-Li Hallin
Anne-Li Hallin
 and 
Peik Gustafsson
Peik Gustafsson
   | Apr 23, 2021
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Published Online: Apr 23, 2021
Page range: 52 - 63
DOI: https://doi.org/10.21307/sjcapp-2021-007
Keywords
© 2021 Pia Tallberg et al., published by sciendo.
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

FIGURE 1.

Flow-ChartADHD = attention deficit hyperactivity disorder; FTF = Five To Fifteen; SNAP-IV = Swanson-Nolan-Pelham scale, version IV; WAIS-IV = Wechsler Adult Intelligence Scales, fourth edition; WISC-IV = Wechsler Intelligence Scales for children, fourth edition
Flow-ChartADHD = attention deficit hyperactivity disorder; FTF = Five To Fifteen; SNAP-IV = Swanson-Nolan-Pelham scale, version IV; WAIS-IV = Wechsler Adult Intelligence Scales, fourth edition; WISC-IV = Wechsler Intelligence Scales for children, fourth edition

FIGURE 2.

Linear diagram presenting slopes of the beta values for the Wechsler composite scores for the ADHD and Control groups between baseline and the 3-4 year follow-up and the slope differences.Notes. β = Beta, not standardized. FSIQ = full scale intelligence quotient. In parenthesis 95% confidence interval. The beta values are controlled for Wechsler version used at first and (WISC-IV and WAIS-IV) and second assessment (WISC-IV and WAIS-IV). ADHD group: T1, n = 125, except for Processing Speed, n = 124; T2, n = 94. Control group: T1 n = 59; T2, n = 52; * = p < 0.05; ** = p < 0.01; *** = p < 0.001
Linear diagram presenting slopes of the beta values for the Wechsler composite scores for the ADHD and Control groups between baseline and the 3-4 year follow-up and the slope differences.Notes. β = Beta, not standardized. FSIQ = full scale intelligence quotient. In parenthesis 95% confidence interval. The beta values are controlled for Wechsler version used at first and (WISC-IV and WAIS-IV) and second assessment (WISC-IV and WAIS-IV). ADHD group: T1, n = 125, except for Processing Speed, n = 124; T2, n = 94. Control group: T1 n = 59; T2, n = 52; * = p < 0.05; ** = p < 0.01; *** = p < 0.001

Results for the predictors in relation to long-term outcomes for each of the Wechsler composites in separate linear mixed model analyses.

Dependent variable Independent variables Groups
ADHD Controls
T1, n = 90, T2, n = 93 T1, n = 59, T2, n = 52
Betaa 95% CI p−value Betaa 95% CI p−value
FSIQ Time (year) −.93 −1.51 ;−.35 .002 1.10 .41 ; 1.79 .002
Girls vs boys 4.10 −1.05 ; 9.25 .117 −1.37 −6.65 ; 3.91 .605
WAIS vs WISC 3.11 −.86 ; 7.07 .119 −.71 −5.34 ; 3.92 .740
Special education supports −.95 −5.80 ; 3.89 .696 −9.25 −16.49 ; −2.02 .013
SNAP IV T1, T2 b −.08 −.23 ; .06 .250 −.04 −.54 ; .45 .861
ADHD medication 1.55 −4.47 ; 7.56 .611
Verbal comprehension Time (year) −.92 −1.58 ;−.26 .007 2.13 1.19 ; 3.06 <.001
Girls vs boys 4.39 −1.35 ; 10.12 .132 −3.75 −10.27 ; 2.77 .253
WAIS vs WISC −5.79 −10.31 ;−1.27 .014 −2.59 −8.78 ; 3.60 .374
Special education supports −3.26 −8.65 ; 2.13 .232 −6.71 −15.65 ; 2.22 .137
SNAP IV T1, T2b −.02 −.18 ; .15 .821 .14 −.47 ; .75 .654
ADHD medication .50 −6.20 ; 7.19 .884
Perceptual reasoning Time (year) −.43 −1.07 ; .21 .184 .88 −.19 ; 1.94 .104
Girls vs boys 1.73 −4.21 ; 7.68 .564 −5.61 −12.20 ; .98 .093
WAIS vs WISC .98 −3.43 ; 5.38 .653 −2.48 −9.45 ; 4.49 .446
Special education supports .29 −5.87 ; 5.30 .919 −7.45 −16.48 ; 1.58 .104
SNAP IV T1, T2 b .07 −.09 ; .23 .390 .02 −.60 ; .64 .954
ADHD medication 1.94 −5.00 ; 8.89 .579
Working memory Time (year) −.28 −1.06 ; .50 .484 −.52 −1.45 ; .41 .268
Girls vs boys .77 −3.95 ; 5.49 .746 4.78 .45 ; 9.11 .031
WAIS vs WISC 5.35 .30 ; 10.40 .039 3.59 −2.22 ; 9.40 .198
Special education supports −.48 −4.92 ; 3.95 .830 −4.06 −10.01 ; 1.88 .176
SNAP IV T1, T2b −.23 −.41 ; −.06 .009 −.23 −.64 ;.17 .252
ADHD medication −.79 −6.28 ; 4.70 .775
Processing speed Time (year) −1.37 −2.21 ; −.53 .002 .30 −.86 ; 1.47 .602
Girls vs boys 6.19 .70 ; 11.68 .028 3.36 −2.17 ; 8.89 .228
WAIS vs WISC 10.51 4.98 ; 16.04 .001 .09 −7.18 ; 7.37 .978
Special education supports 3.02 −2.14 ; 8.18 .248 −9.52 −17.11 ; −1.94 .015
SNAP IV T1, T2 b −.12 −.32 ; .07 .212 −.16 −.68 ; .36 .538
ADHD medication 2.91 −3.48 ; 9.30 .369

Means and standard deviations for scores on the Wechsler scales and SNAP-IV for ADHD and Control participants

Groups
ADHD Controls
Baseline measures n Mean (SD) n Mean (SD)
WISC-IV/WAIS-IV 120/5 59/0
FSIQ 125 88.90 (12.67) 59 96.51 (9.71)
Verbal comprehension 125 93.43 (13.36) 59 95.12 (12.97)
Perceptual reasoning 125 97.06 (14.04) 59 101.41 (12.00)
Working memory 125 82.03 (12.95) 59 93.02 (10.45)
Processing speed 124 88.69 (13.59) 59 98.42 (11.06)
SNAP–IV 116 30.69 (10.58) 59 5.98 (6.81)

Results of logistic regression models of the relationship between the dependent variable grades at follow-up, and the independent variables parent rated SNAP-IV scores, and Wechsler composites in the ADHD group

Model statistics Variables Odds Ratio 95% CI p-value
T1 Measures SNAP-IV T1 .99 .94 ; 1.04 .678
Χ2 = 5.86 Verbal comprehension 1.05 1.00 ; 1.10 .031
df = 5 Perceptual reasoning .99 .96 ; 1.04 .788
p for model = .32 Working memory .98 .94 ; 1.02 .335
Nagelkerke R2 = .094 Processing speed 1.00 .97 ; 1.04 .815
n = 82
T2 Measures SNAP-IV T2 .92 .87 ; .98 .007
Χ2 = 23.80 Verbal comprehension 1.11 1.04 ; 1.19 .001
df = 5 Perceptual reasoning 1.01 .96 ; 1.07 .624
p for model < .001 Working memory .95 .89 ; 1.00 .073
Nagelkerke R2 = .356 Processing speed 1.00 .96 ; 1.04 .897
n = 79

Descriptive clinical data of parent-rated comorbid symptoms at the baseline in the ADHD group

Percentiles
FTF variables < 90 ≥ 90 < 98 ≥ 98
n % n % n %
Motor skills 67 60 35 31 10 9
EF 14 12 62 55 36 32
Perception 46 41 51 46 15 13
Memory 39 35 58 51 16 14
Language 54 48 40 35 19 17
Learning 25 26 39 41 32 33
Social skills 38 34 56 50 19 17
Externalized 27 24 39 34 47 42
Internalized 59 52 38 34 16 14
Compulsivity 71 57 34 27 8 6
eISSN:
2245-8875
Language:
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Publication timeframe:
Volume Open
Journal Subjects:
Medicine, Basic Medical Science, other
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