AuthorYear of publication | Geographical area | Sample | NDDs considered | Sample age | Time window | Differences in sex | Methodology/ type of study | Diagnostic criteria | Sources of information | Type of population |
---|---|---|---|---|---|---|---|---|---|---|
Bosch et al., 2021 | Catalonia (Spain): 28 schools | 6834 students | All NDDs according to DSM-5: ID, ASD, ADHD, SLD, CDs and MDs | 5–17 years | Not specified; two-phase study, initiated in 2011 | Yes, ASD and MD were more common in boys than in girls | Prevalence study | DSM-5 | Directly from the child through the administration of specific tests in phase 1; assessment by expert psychiatrists and neuropsychologists in phase 2 | School: public and private. Rural and urban |
Bita et al., 2018 | LAMIC: Africa n = 16 (31.4%) (77.6%), Asia–Pacific n = 19 (37.3%), Western Europe n = 7 (13.7%), Latin America n = 7 (13.7%), multisite n = 2 (3.9%) | 274,028 subjects 51 studies | ADHD ASD Other neurological conditions: epilepsy, hearing impairment, visual impairment, ADHD, behavioural/emotional problems, mental disorders | < 19 years | Since 1995 | Not estimated | Systematic review and meta-analysis | None | Multiple surveys | General (Rural and urban) |
Arora et al., 2018 | India (5 regions): north-central (Palwal), north (Kangra), east (Dhenkanal), west (north Goa) and south (Hyderabad) | 3964 children (83.9% of all invited candidates; 99.4% of all enrolled subjects) Composition: 2,006 boys and 1,958 girls | NDD: visual impairment, epilepsy, neuromotor impairment including cerebral palsy, hearing impairment, speech and language disorders, ASD and ID Children from 6 to 9 years old: ADHD and learning disorders | 2–9 years | Data were collected between 5 December 2011 and 27 September 2012 | No significant difference Prevalence: 12.4% (95% CI 10.2%-15.0%) in boys versus 10.2% (95% CI 8.4%-12.2%) in girls (p = 0.146) | Prevalence study | DSM-IV-TR Validated tools for ASD, ADHD and epilepsy (INCLEN Diagnostic Tool) | Cross-sectional survey of children's parents and interviews by accredited professionals, demographic details extracted in the 2011 Indian census | General (rural and urban) |
Carballal et al., 2017 | Galicia (Spain) | 1286 children | Child and adolescent psychiatric pathology | 0–14 years | Between September and November 2015 | Not determined | Observational, descriptive and cross-sectional study | DSM-IV-TR | Interview and review of clinical history according to DSM-IV-TR axes Professional evaluators: 57% school counsellors, 42% child–adolescent mental health unit, 37% public neuropaediatricians, 33.6% schoolteachers, 27.4% speech therapists and 15% early care services | Patients receiving primary mental health services and follow-up by child–adolescent mental health unit |
Wang et al., 2017 | China: East China (20 studies), Central China (10), South China [11], Southwest China (seven), North China (six), Northwest China (five), Northeast China (four) and Hong Kong/Taiwan (four) | 275,502 subjects out of 334,000 recruited 67 studies | ADHD | Up to 18 years | 30 years | Not determined | Systematic review and meta-analysis | DSM (n = 86.57%) DSM-III, DSM-III-R, DSM-IV and DSM-5 CCMB-2, CCMB-3, ICD-9 | Clinical interviews were administered in 58.2% (n = 39) of the studies analysed Medical information was collected from the children (n = 4), teachers and parents in the remaining studies | General |
Catalan-Lópet al., 2012 | Spain | 13,026 subjects 14 studies | ADHD | < 18 years | Original studies published between January 1980 and August 2011 | Male:female ratio of 4:1 in four studies and 2:1 in three studies Higher prevalence in males | Systematic review and meta-analysis | DSM-III-R, DSM-IV and ICD-10 | Symptom-based questionnaires and scales Parents and teachers In half of the studies, data collection was divided into 2 stages: (1) psychometric screening and (2) clinical confirmation using standardized diagnostic criteria | General (30%) and school |
Pérez Crespo et al., 2019 | Catalonia (Spain) | 1,326,666 children (51.5% boys and 48.5% girls) | ASD | 2–17 years The most common age range was 6–10 years (48.2%), followed by 2–5 years (30.3%) and 11–17 years (21.5%) | Between 2009 and 2017 | 4.5 times more common in boys (12,647 boys versus 2,819 girls) | Retrospective analytical cohort study | ICD-9 ICD-9 codes 299.0, 299.1, 299.8, and 299.9 | Based on ICD diagnoses in the Catalan Health System | Clinic patients |
Kita et al., 2020 | Japan | 3852 children | NDD: ADHD, ASD, SLD (DD) and coordination disorder First study to measure comorbidity between them The prevalence of ODD was also estimated because of its high comorbidity with ADHD | 6–9 years | 2015 (cross-sectional) | Not calculated | Cross-sectional prevalence study (2015) conducted in schools through parents and teachers, with response rates of 63.9% and 22.5%, respectively | DSM-5 SNAP-IV for ADHD SRS-2 for ASD RWC scale for dyslexia (SLD) Movement Assessment Battery for Kids – Second Edition Checklist (MC) for Motor Disorders | Surveys Based on parent–teacher rating scale questionnaires Two evaluators All rates of agreement on children with suspected NDDs were low (range, 6–16%) | Pupil, community |
Fleming et al., 2020 | Scotland | 766,244 subjects (390,290 [50.9%] boys; 375,954 [49.1%] girls) | ASD ID ADHD Depression | 4–19 years | Subjects attended school between 2009 and 2013 | Multimorbidity was more common among boys Girls were less likely than boys to have multimorbidity but experienced a greater adverse impact on educational outcomes | Cross-sectional cohort study | ASD from additional support needs ADHD if they have received treatment with stimulants or nonstimulants Depression if they have received antidepressant treatment | Educational and health databases (Scottish Educational Data Exchange Unit (ScotXed) and 2 health databases through ISD (Information Services Division) | Pupil |
Hansen et al., 2018 | Norway | 407 children | Prevalence rates of NDDs (ADHD, TD, ASD) and comorbid disorders Comorbidity between different NDDs | 7–13 years | Between September 2007 and February 2009 | Boys constituted a significant majority of referred children (66.3%). There were no significant differences in gender distribution or mean age between the overall NDD group and the psychiatric disorder group without NDDs or between any two specific NDD groups. Among children with ADHD, a significantly higher proportion of girls than boys had comorbid anxiety disorders | Cross-sectional study | DSM-IV | Cross-sectional interviews of parents (at a single timepoint) by experienced doctors Instruments: validated diagnoses in children, Schedule for Affective Disorders and Schizophrenia – Present and Lifetime version (Kiddie-SADS-PL), DSM-IV version | Clinical: Consultation External CAMHS |
Dalsgaard et al., 2020 | Denmark | 14.4 million person-years of follow-up | All mental health disorders | Up to 18 years | From 1 January 1995 to December 31, 2015 | Anxiety was the most common diagnosis in girls (7.85%) ADHD was the most common disorder in boys (5.90%). The overall risk of being diagnosed with a mental disorder before 6 years of age was 2.13% overall, with a higher risk in boys (2.79%) than in girls (1.45%) | Cohort study | ICD-10 Classification of Mental and Behavioural disorders: Diagnostic Criteria for Research (ICD-10-DCR), ICD-10 | Comprehensive clinical evaluations of all mental disorders by interdisciplinary clinical teams including child and adolescent psychiatrists | Departments in public hospitals Records in the Health System Central Registry of Psychiatric Investigations of Denmark and National Registry of Patients of Denmark |
Sayal et al., 2017 | Community in general, international studies (USA, UK, Japan, Norway, Ireland, Denmark, Scotland, Sweden, Israel, Netherlands, Germany, Thailand and Australia) | 7 systematic reviews | ADHD | Two age groups: children aged ≤ 6 years and adolescents aged up to 18 years transitioning to adult services | Publications between 1996 and 2016 | More common in males by a factor of 2–3 | Review | DSM-IV | Parent ratings, teacher assessments, or best-estimate diagnostic procedures Data on pharmacological prescriptions | Primary care School Insurance Private practice |
Saito et al., 2020 | Hirosaki, Japan | 5016 children were eligible 3954 children completed and returned the screening package 559 children were assessed comprehensively in person | ASD and its comorbidity with other NDDs | 5 years | 2013–2016 | The raw male:female prevalence ratio was 2.2:1 Common comorbid conditions included ADHD (50.6%, male:female = 2.4:1), DCD (63.2% male:female = 2.1:1), ID (36.8%, male:female = 1.7:1), and borderline intellectual functioning (20.7%, male:female = 2.6:1) | Sequential-cross-sectional design study | DSM-5 Autism Spectrum Screening Questionnaire (ASSQ), Strengths and Difficulties Questionnaire (SDQ), ADHD IV Rating Scale (ADHD-RS-IV), Developmental Coordination Disorder Questionnaire (DCDQ), and Parental Stress Index (PSI) DISC and ADOS for ASD WISC-IV MABC-2: For T. of movement | Comprehensive assessment, which included interviews with children and parents, behavioural observation, and tests of cognitive and motor function. All cases were reviewed by a multidisciplinary research team | HFC Facts (Hirosaki Five- year-old Children Developmental Health Check-up) |
Shriberg et al., 2019 | USA | 346 participants | The objective of this research was to use measurements and analyses in a diagnostic classification system to estimate the prevalence of speech and language disorders in convenience samples of speakers with one of the eight types of complex NDD | Average of 13.3 years | 30 years | No sex differences were detected in the prevalence of disorders | Prevalence study | SSD (Speech Sound Disorders) | Audio recordings of speech Narrow phonetic transcription, prosody–speech coding, and acoustic analysis Research specialists in the field | Population- specific database of participants recruited for studies of genetic and behavioural disorders of speech sound production (i.e., excluding disfluency) |
Murphy et al., 2015 | Midwestern states, USA | 136 children | Language disability Preschool language and early literacy skills One-quarter of children (21%, n = 29; 1%, n = 2 missing information) had moderate disabilities, including ASD (n = 13), ADHD (n = 2), Down syndrome (n = 2), developmental delay (n = 2), hearing loss (n = 1) and foetal alcohol syndrome (n = 1) | Average of 56 months (SD = 4.5, range 48–69 months) | Cross-sectional | Not determined | Retrospective prevalence study | No DSM; criteria were specified | Experienced professionals and caregivers Word recognition task | Pupil population: children with language disabilities attending special education schools |
Fortes et al., 2015 | Low- and middle-income areas of Brazil | 1618 children and adolescents | Learning disorders and their comorbidity with other homo- and heterotypic psychiatric disorders | at least 9 years of schooling | Cross-sectional | Yes, learning disorder and ADHD were more prevalent in males than in females Significant differences in prevalence rates were detected between cities, and several sociodemographic correlates (age, sex, IQ and socioeconomic status) were significantly associated with SLD with global impairment in this sample | Cross-sectional prevalence study | DSM-5 | Direct observation by qualified psychologists | Pupil |
Faraone et al., 2021 | Worldwide | Studies in the analysis included > 2000 participants | ADHD | All ages | 20 years | ADHD is more common in men than in women. The meta-analysis examined parents' ratings of symptoms in 29 studies with more than 42,000 participants, as well as teacher ratings in 24 studies with more than 56,000 participants; a male:female ratio of 2:1 was found in youth | Systematic review, international consensus of ADHD We reviewed studies with more than 2000 participants or meta-analyses of five or more studies or 2000 or more participants | DSM | Studies with scientific evidence | General, clinical, pupil |