Table 3.
Characteristics and results of included studies.
| Study | Participants (ADHD and Controls) | Experimental Group | Mean Age (SD) | Gender (Male, Female) | Control Group | Mean Age (SD) | Gender | Inclusion and Exclusion Criteria for ADHD | ADHD Presentation | Medication (Psycho-stimulant) | Handwriting Measures | Q (Quality) S (Speed) P (Process) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Adi-Japha et al., 2007 [28] | 40 | 20 | 12.2 (5.7) | 20 M | 20 | 12.8 (3.6) | 20 M | Inclusion criteria: formal diagnosis of ADHD, IQ score > 85, performance within 1.6 SD on a reading test; Exclusion criteria: reading problems. | ADHD/C | Off-state for at least a week before the experiment. | Graphic production on a digitizing tablet; Letters production. | Q and P |
| Åsberg Johnels et al., 2014 [35] | 55 | 20 | 10 to 16 | 20 F | 35 | 10 to 16 | 35 F | Inclusion criteria: formal diagnosis of ADHD, IQ score > 69; Exclusion criteria: ASD, neuropsychiatric and neurodevelopmental disorders, learning disabilities. | n.s | No medication | FTF; Parental ratings. | Q |
| Borella et al., 2011 [36] | 30 | 15 | 9.3 (1.4) | 12 M; 4 F | 15 | 9.4 (1.4) | 12 M; 3 F | Inclusion criteria: formal diagnosis of ADHD; Exclusion criteria: IQ score < 85, MPH medication, learning disability, mathematical or reading disorders, neurological, sensory, motor, psychiatric or mood disorders. | 5 ADHD/I; 10 ADHD/C | No medication | Batteria per la valutazione delle competenze ortografiche nella scuola dell’obbligo; Continuous letters production. | S and P |
| Capodieci et al., 2018 [37] | 32 | 16 | 10.5 (6.9) | 12 M; 4 F | 16 | 10.1 (6.4) | 12 M; 4 F | Inclusion criteria: formal diagnosis of ADHD for only one child, all others on the basis of an ad-hoc questionnaire; Exclusion criteria: Neurological, psychiatric or serious psychological problems; No child had a learning disability. | n.s | No medication | BVSCO-2; Words production. | Q, S and P |
| Capodieci et al., 2019 [38] | 52 | 26 | 9.6 (1.2) | 22 M; 4 F | 26 | 9.3 (1.1) | n.s | Inclusion criteria: formal diagnosis of ADHD for all but 3 children; Exclusion criteria: neurological or psychological problems, learning disorders. | 10 ADHD/I; 10 ADHD/C; 6 ADHD/HI | No medication | BVSCO-2; Dictation tasks; Sentences and words production; Handwriting legibility scale. | Q, S and P |
| Dirlikov et al., 2017 [39] | 167 | 45 | 9.9 (1.2) | 39 M; 6 F | 65 | 9.9 (1.1) | 56 M; 9 F | Inclusion criteria: formal diagnosis of ADHD; Exclusion criteria: intellectual disability, seizures, neurological, chronic medical, genetic, psychiatric (except ODD), speech-related, autistic or psychotic disorders. | 7 ADHD/I; 38 ADHD/C | Off-state for at least 24 h before the experiment. | MHA; Copy task. | Q, S and P |
| Farhangnia et al., 2020 [40] | 48 | 24 | 8.0 (0.7) | 17 M; 7 F | 24 | 8.1 (0.6) | 17 M; 7 F | n.s | n.s | n.s | PHAT; Copy task and dictation task. | Q and S |
| Flapper et al., 2006 [41] | 24 | 12 | 9.8 (1.7) | 11 M; 1 F | 12 | 9.7 (1.2) | 11 M; 1 F | Inclusion criteria: formal diagnosis of ADHD+DCD; Exclusion criteria: learning, neurological or psychiatric disorders, IQ score < 70. | 6 ADHD/I; 4 ADHD/C; 2 ADHD/HI | Off-state for the first assessment; On-state for 4 to 5 weeks for the second assessment. | BHK; Copy task. | Q and S |
| Frings et al., 2010 [42] | 21 | 10 | 12.3 (1.3) | 10 M | 11 | 12.1 (1.8) | 9 M; 2 F | Inclusion criteria: formal diagnosis of ADHD. | 10 ADHD/C | On-state | Copy task | Q |
| Hung and Chang, 2022 [30] | 60 | 30 | 7.1 (0.5) | 16 M; 14 F | 30 | 7.2 (0.5) | 16 M; 14 F | Inclusion criteria: formal diagnosis of ADHD; Exclusion criteria: ASD, seizure disorder, IQ < 80, mental retardation, mood disorders, anxiety or psychotic disorders. | 9 ADHD/I; 18 ADHD/C; 3 ADHD/HI | n.s | BCBL; Copy task and dictation task. | Q, S and P |
| Johnson et al., 2013 [43] | 35 | 14 | 11.0 (1.95) | 14 M | 21 | 11.0 (2.1) | 21 M | Inclusion criteria: formal diagnosis of ADHD; Exclusion criteria: medical, sensory, genetic or neurodevelopmental disorders, intellectual disability. | 14 ADHD/C | Off-state for at least 24 to 72 h before the experiment. | HPT; Copy task. | Q, S and P |
| Langmaid et al., 2014 [44] | 28 | 14 | 10.9 (2.0) | 14 M | 14 | 10.6 (2.3) | 14 M | Inclusion criteria: formal diagnosis of ADHD; Exclusion criteria: medical, sensory, genetic or neurodevelopmental disorders, intellectual disability. | 14 ADHD/C | Off-state for at least 24 to 72 h before the experiment. | Cursive letters production on a digitizing tablet. | P |
| Langmaid et al., 2016 [45] | 28 | 14 | 10.8 (2.0) | 14 M | 14 | 10.5 (2.2) | 14 M | Inclusion criteria: formal diagnosis of ADHD; Exclusion criteria: medical, sensory, genetic or neurodevelopmental disorders, intellectual disability. | 14 ADHD/C | Off-state for at least 24 to 72 h before the experiment. | Cursive letters production at 10 mm and 40 mm on a digitizing tablet. | P |
| Laniel et al., 2020 [46] | 25 | 12 | 9.5 (1.1) | 8 M; 4 F | 12 | 9.9 (1.3) | 6 M; 6 F | Inclusion criteria: formal diagnosis of ADHD; Exclusion criteria: Intellectual disability; One child had ODD and an anxiety disorder, another had dyspraxia. | n.s | On-state | BHK; Copy task; Pen-stroke test on a digitizing tablet. | Q, S and P |
| Lofty et al., 2011 [47] | 40 | 20 | 7.8 (1.2) | n.s | 20 | 7.8 (1.2) | 20 M | Inclusion criteria: formal diagnosis of ADHD; Exclusion criteria: sensory or psychiatric disorders; 60% of included children met criteria for dyslexia. | n.s | n.s | DDS; Copy task. | Q |
| Okuda et al., 2011 [48] | 22 | 11 | 8.6 to 11.6 | 11 M | 11 | n.s | n.s | Inclusion criteria: formal diagnosis of ADHD; Exclusion criteria: sensory or psychiatric disorders. | n.s | On-state | Scale of dysgraphia | Q |
| Rosenblum et al., 2008 [32] | 24 | 12 | 8 to 10 | 10 M; 2 F | 12 | 8 to 10 | 10 M; 2 F | Inclusion criteria: formal diagnosis of ADHD; Exclusion criteria: another medical diagnosis. | n.s | On-state | HHE on a digitizing tablet; Copy task. | Q, S and P |
| Shen et al., 2012 [27] | 42 | 21 | 8.5 (1.2) | 17 M; 4 F | 21 | 8.5 (1.0) | 17 M; 4 F | Inclusion criteria: formal diagnosis of ADHD, with possible ODD and CD in the ADHD group; Exclusion criteria: epilepsy, severe anxiety, psychotic disorder, DCD (score < 15th percentile on the M-ABC 2). | 6 ADHD/I; 10 ADHD/C; 5 ADHD/HI | Off-state for at least 24 h before the experiment. | THPS; BRWT; Copy task and dictation task on a digitizing tablet. | Q, S and P |
| Tucha and Lange, 2001 [49] | 42 | 21 | 10.7 (0.4) | 21 M | 21 | 10.5 (0.4) | 21 M | Inclusion criteria: formal diagnosis of ADHD, with medication; Exclusion criteria: Concurrent psychotropic medications, ADHD/I or ADHD/HI, reading disability or spelling disorder; Four children had a mathematics disability. | 21 ADHD/C | Off-state for at least 10 h before the experiment and on-state 1 h after the administration. | Copy task and dictation task on a digitizing tablet. | Q and P |
| Tucha and Lange, 2004 [31] | 20 | 10 | 9.9 (n.s) | 5 M; 5 F | 10 | 9.9 (n.s) | 5 M; 5 F | Inclusion criteria: formal diagnosis of ADHD, with possible ODD and CD in the ADHD group; Exclusion criteria: neurological and psychiatric disorders. | n.s | On-state | Sentences production on a digitizing tablet. | P |
| Yoshimasu et al., 2011 [50] | 5699 | 379 | 10.4 (4.6) | 284 M; 95 F | 5320 | n.s | 2666 M; 2654 F | Inclusion criteria: retrospective cohort-based study which has sought formal diagnosis of ADHD (based on DSM criteria); Exclusion criteria: IQ score < 50, written language disorder with or without reading disability. | n.s | Possible medication | Information retrieved from individualized education program goals for written language and/or specific writing subtest scores ≤ 90; Legibility and/or writing subtest scores. | Q |
Abbreviations: ADHD: attention deficit hyperactivity disorder; ADHD/C: combined presentation; ADHD/I: inattentive presentation; ADHD/HI: hyperactive–impulsive presentation; ASD: autism spectrum disorders; BCBL: Battery of Chinese Basic Literacy; BHK: Concise Assessment Scale for Children’s Handwriting; BRWT: Basic Reading and Writing Comprehensive Test; BVSCO-2: Batteria di Valutazione della Scrittura e della Competenza Ortografica 2; CD: conduct disorder; DCD: developmental coordination disorder; DDS: Dysgraphia Disability Scale; DSM: Diagnostic and Statistical Manual; F: female; FTF: Five to Fifteen Questionnaire; HHE: Hebrew Handwriting Evaluation; HPT: Handwriting Performance Test; IIV: intra-individual variability; IQ: intelligence quotient; M: male; MHA: Minnesota Handwriting Assessment; MPH: methylphenidate; n.s: not specified; ODD: oppositional defiant disorder; PHAT: Persian Handwriting Assessment Tool; THPS: Tseng Handwriting Problem Checklist; WM: working memory.