Introduction
Current aims
Methods
Search strategy
1. (ASC or ASD or Asperg* or Autis* or 'high#functioning' or 'pervasive developmental disorder' or PDD or HFA) |
2. ('possib* autis*' or 'autis* trait*' or 'autis* phenotyp*' or 'undiagnosed autis*' or 'self-diagnos* autis*') |
3. (suicid* or 'suicide plans' or 'suicide attempts' or 'attempted suicide' or parasuicide 'self-harm' or 'self-inj*') |
4. #1 or #2 |
5. #3 and #4 |
6. Limit #5 to yr = ”1992—current” |
Selection strategy
Inclusion criteria | Exclusion criteria |
---|---|
Participants with a formal diagnosis of ASC Participants who are possibly autistic (but undiagnosed) Data for autistic and/or possibly autistic participants provided separately to any additional groups Prevalence estimates of suicidality reported using ICD or DSM clinical definition Empirical quantitative studies, following cross-sectional, longitudinal, cohort or case–control designs Published from 1992 to present day | Autistic or possibly autistic participants with co-occurring intellectual disability Prevalence estimates only provided for self-harm or self-injury without suicidal intent, or where measurement items do not distinguish these from suicidality Conference abstracts, conference papers, review articles, editorials or book chapters Grey literature (e.g. theses) Empirical qualitative studies, or other systematic reviews and meta-analyses Not published and/or available in English |
Selection process
Data extraction and synthesis
Quality assessment
Statistical analysis
Results
Study characteristics
Study | Autism | Participant characteristics | Measures | Prevalence | ||||
---|---|---|---|---|---|---|---|---|
Authors | Country | Design | Group | Comparator | Sex, Age, Age of diagnosis, IQ, Comorbidity, Employment | Autism and Possible Autism | Suicidality measure, type of report, timeframe, specific items/questions | Suicidality |
Anderson et al. (2020) | Australia | Cross-sectional | Nonclinical 102 Autistic | - | 54.6% Male Age range 18–25 + Age diagnosed: 0–12 years (40%), 13–17 years (21%), 18 + years (37%), Unknown (2%) Q unknown (university students) Comorbidity: Depression (40%), Anxiety (68%), ADHD (31%), SH (16%) | Self-identified formal diagnosis | Unstandardised (self-report) Unspecified timeframe Optional questions "During the time I have been a university student… I have never thought about suicide/ I have thought about suicide, but I would not act on those thoughts/ I have made plans to suicide, but I did not act on those plans/ I have attempted suicide" | SI: 37 (48%) SP: 9 (12%) SAB: 1 (1%) |
Arwert & Sizoo (2020) | The Netherlands | Cross-sectional | Clinical 75 Autistic | - | 61.1% Male Age range 19–64 (M = 35.9, SD = 12.96) IQ threshold > 70 Comorbidity: Measured symptoms of Depression Employed: paid (42.7%), voluntary (25.3%) | Formal diagnosis | BSS (self-report) SI: Past 2 weeks SA: Lifetime | SI: 47 (65.3%) SAB: 21 (29.2%) |
Bal et al. (2021) | Korea | Cross-sectional | Nonclinical 86 Autistic (KP ASC)1 1292 Possibly autistic (864 KP/ 223 CHEER/ 205 Sooncheon) | 3 population-based samples (14,423 KP/ 3702 CHEER/ 4837 Sooncheon) | Autistic 80.2% Male Age range 7–12 (M = 8.88, SD 1.60) IQ (M = 93.84, SD = 25.3; WISC-III), 17.4% had IQ < 70 Comorbidity: Anxiety (38.4%), Hyperactivity (55.8%) Possibly Autistic 62.5% Male KP (M = 9.43, SD = 1.69); CHEER (M = 10.91, SD = 0.98); Sooncheon (M = 8.82, SD = 1.53) IQ unknown (assumed to have intellectual function in the average range) Comorbidity: Anxiety (KP 38.6%; CHEER 29%; Sooncheon 38.6%), Hyperactivity (KP 55.3%; CHEER 57.9%; Sooncheon 64.9%) | ADI-R ADOS ASSQ DSM-V | BASC-2 PRS-C (informant-report) Past several months Item 92 "I want to die" or "I wish I were dead" and item 138 "I want to kill myself" | Autistic KP ASC SI: 12 (14%) Possibly KP SI: 171 (19.8%) CHEER SI: 61 (27.4%) Sooncheon SI: 34 (16.6%) |
Balfe & Tantam (2010) | UK | Cross-sectional | Nonclinical 42 Autistic | - | 88.1% Male Age range 13–64 (M = 26.21, SD = 11.9) IQ threshold ≥ 70 Comorbidity: Depression (35%), Anxiety (51%), Alcohol problems (15%), Drug problems (10%) Employed: paid (28%), voluntary (25.3%) | ADI-R Documented proof | Unstandardised (self-report) Unspecified timeframe "Have you ever thought about killing yourself?" and "Have you ever tried to kill yourself?" | SI: 17 (40%) SAB: 6 (15%) |
Bemmouna et al. (2021) | France | Intervention | Clinical 7 Autistic | - | 57% Male (n = 3) Age range 19–56 (M = 27.71, SD = 13.34) IQ threshold > 80 (M = 108.8, SD = 25.69; WAIS-IV) Comorbidity: BPD (14%), ADHD (29%), SH (57%) Employed: 14% | ADI-R ADOS-2 | Unstandardised pre-inclusion interview questions (self-report) SI: Past year SA: Lifetime "Do you have any history of suicide attempts?/ In difficult situations, some people may have suicidal ideation. Does this apply to you?” | SI: 5 (71%) SAB: 5 (71%) |
Cassidy et al. (2021) | UK | Cross-sectional | Nonclinical 308 Autistic (formal diagnosis) 113 Possibly autistic (suspected diagnosis) | 268 Non-autistic | Autistic 27% Male Age (M = 39.71, SD = 13.34) IQ unknown (without ID specified) Comorbidity: Depression (50%), Anxiety (59.74%), PTSD (17.86%), OCD (9.42%), Bipolar Disorder (4.55%), Anorexia (3.9%), Bulimia (1.62%), Personality disorder (6.49%), ADHD (13.64%), lifetime NSSI (62.7%) Employed: full-time (30.19%), part-time (21.43%), voluntary (10.71%) Possibly Autistic 29.2% Male Age (M = 40.34, SD = 13.55) IQ unknown (without ID specified) Comorbidity: Depression (39.82%), Anxiety (44.25%), PTSD (13.27%), OCD (2.65%), Bipolar Disorder (2.65%), Anorexia (0.88%), Bulimia (0.88%), Personality disorder (7.96%), ADHD (7.96%), lifetime NSSI (46.4%) Employed: full-time (41.49%), part-time (16.81%), voluntary (7.07%) | AQ Self-identified formal and suspected diagnosis | SBQ-R (self-report) Lifetime | Autistic SI: 86 (27.9%) SP: 90 (29.2%) SAB: 113 (36.7%) Possibly Autistic SI: 53 (46.9%) SP: 24 (21.2%) SAB: 26 (23%) |
Cassidy et al. (2018) | UK | Cross-sectional | Nonclinical 164 Autistic (65 Male/ 99 Female) | 169 General Population (54 Male/ 115 Female) | 39.6% Male IQ unknown (without ID specified) Comorbidity: Depression (79.8%), Anxiety (71.3%), OCD (14.6%), Bipolar (4.9%), Anorexia (5.5%), Bulimia (1.2%), Schizophrenia (3.7%), Personality Disorder (14%), ADHD (6.7%), NSSI (64.6%) Male Age range 20–60 (M = 41.52, SD = 11.73) Age at diagnosis (M = 34.55, SD = 14.75) 46.2% Employed FemaleAge range 20–60 (M = 38.89, SD = 10.47) Age at diagnosis M = 35.06, SD = 11.83) 51.5% Employed | AQ-S Self-identified formal diagnosis | Unstandardised patient screening questionnaire (self-report) Lifetime “Have you ever felt suicidal? If yes, have you ever planned or attempted suicide?” | SBQ-R ≥ 8: 118 (72%)2 SAB: 63 (38.4%) |
Cassidy et al. (2014) | UK | Cross-sectional | Nonclinical 374 Autistic | - | 68% Male Age range 17–67 Age at diagnosis (M = 31.5, SD = 10.9) IQ unknown (diagnosed AS) Comorbidity: Depression (32%), OCD (1.1%), Eating Disorder (0.5%), ADHD (1.1%) | AAA AQ Clinical judgement | SBQ-ASC (self-report) Lifetime | SI: 243 (66%) SP/SA: 127 (35%)2 |
Chang et al. (2021) | Taiwan | Cohort | Clinical & TGNC 88 Autistic (24 GD/ 64 No GD) | 42 age + sex matched TD | 89.8% AMAB Age range 17–24.5 (at follow up: M = 20.4, SD = 2.0) IQ threshold ≥ 70 (M = 97.40, SD = 20.47; WISC-III, WAIS-III) Comorbidity excluded: Any major psychiatric disorders, SH (13.6%) | ADI-R (Chinese) DSM-IV-TR SRS | ASRI-4 (Chinese; self-report) Lifetime Item 41 “I think about death or suicide” and item 50 “Have you ever attempted suicide” | GD SI: 11 (45.9%) No GD SI: 18 (28.1%) GD SA: 2 (8.3%) No GD SA: 5 (7.8%) |
Chaplin et al. (2021) | UK | Cross-sectional | Nonclinical 12 Autistic (ADOS positive) 36 Possibly autistic (traits) | 153 No NDD | 100% Male Age range 20–50 + IQ unknown (screened with LDSQ) Autistic Comorbidity: Depression (18.2%), GAD (18.2%), PTSD (9.1%), OCD (27.3%), Mania/hypomania (9.1%), Alcohol dependency (9.1%), Drug dependency (18.2%), SH (18.2%) Possibly Autistic Comorbidity: Depression (29.7%), GAD (27%), PTSD (16.2%), OCD (21.8%), Mania/hypomania (21.6%), Psychosis (8.1%), Alcohol dependency (21.6%), Drug dependency (32.4%), SH (18.9%) | ADI-R ADOS AQ-10 AQ-20 | MINI (self-report) and ICD-10 SI: Past month A: Lifetime | Autistic SI: 3 (27.3%) SAB: 5 (45.5%) Possibly Autistic SI: 11 (30.6%) SAB: 24 (64.9%) |
Costa et al. (2020)2 | Luxembourg | Cross-sectional | Nonclinical 150 Autistic | 189 Non-autistic | 32.7% Male Age range 18–64 (M = 33.74, SD = 11.81) IQ unknown (without ID specified) Comorbidity: Depression (67%), Anxiety (38%), Other (39%) | AQ-S Self-identified formal diagnosis | SBQ-R (self-report) Lifetime | SBQ-R ≥ 8: 94 (62.7%) |
Dell'Osso et al. (2019)2 | Italy | Cross-sectional | Nonclinical 34 Autistic (ASC) 68 Possibly autistic (traits) | 160 Non-autistic | Autistic 52.9% Male (n = 16) Age (M = 29.8, SD = 12.1) Comorbidity: Anxiety (17.8%), Eating Disorder (5.9%) Possibly Autistic 70.6% Male (n = 20) Age (M = 21.5, SD = 3.1) Comorbidity: Anxiety (33.8%), Bipolar (8.8%) Eating Disorder (11.8%) IQ unknown (without ID specified) | AdAS Spectrum DSM-V | MOODS-SR lifetime version (self-report) Lifetime | Autistic Overall: 12 (35.3%) Possibly Autistic Overall: 29 (42.6%) |
Demirkaya et al. (2016) | Turkey | Retrospective chart review | Clinical 55 Autistic | - | 89% Male Age range 7–20 (M = 13.56, SD = 2.9) IQ range 70–126 (M = 93.53, SD = 14.52; WISC-R, Cattell Scale, Stanford-Binet Scale) Comorbidity: Depression (18.2%), Anxiety (43.6%), OCD (18.2%), Bipolar Disorder (5.5%), Psychotic Features (9.1%), ADHD (65.5%), Self-mutilation (34.5%) | Medical records DSM-IV-TR | Eskin's Suicide Screening Questionnaire (self-report) SI: Past 12 months SAB: Lifetime | SI: 9 (16.3%) SAB: 7 (12.7%) |
Dow et al. (2021) | US | Cross-sectional | Nonclinical 98 Autistic | - | 68.4% Male Age (M = 28.2, SD = 10.9) IQ unknown (lack of legal guardianship as proxy for intellectual functioning) Comorbidity: Depression (55.1%), Panic, stress or worrying (63.3%) Employed: 36.7% | Documented proof | DSI-SS (self-report) SI/SP: Past 2 weeks SA: Lifetime | SI: 12 (12.2%) SP: 2 (2.1%) SAB: 19 (19.4%) |
Green et al. (2000) | UK | Cross-sectional | Clinical 20 Autistic | 20 Conduct Disorder | 100% Male Age range 11–19 (Mdn = 13.75) IQ range 71–141 (M = 92.15, SD = 17.70; WISC, WAIS) Comorbidity: MDD (5%), Dysthymia (25%), GAD (35%), OCD (25%), Hyperkinetic (5%) | ADI ADOS ICD-10 | IOWS (self-report) Past 3 months | SI: 2 (10%) |
Greger et al. (2015) | Norway | Cross-sectional | Nonclinical 75 Possibly autistic | 237 exposed to maltreatment/ 98 no maltreatment | 46.7% Male Age range 12–20 (M = 16.9) IQ (M = 87.8; met criteria for AS) Comorbidity: Depression (52%), Anxiety (50.6%), ADHD (34.7%) | ASDI DSM-IV | CAPA (informant-report) SI/SP: Past 3 months SA: Lifetime | SI: 10 (13.3%) SP: 5 (6.9%) SAB: 27 (36%) |
Hirvikoski et al. (2020) | Sweden | Case-cohort | Nonclinical 43,570 Autistic (Without ID) | 4 groups (24,535 ASC without ID or ADHD/ 19,035 ASC with ADHD without ID/ 7704 ASC with ID without ADHD/ 2894 ASC with ID and ADHD) 270,840 age + sex matched controls without NDD | IQ unknown (ID comparison group) With ADHD 68.2% Male Age at SA (M = 21.99, SD = 8.91) Age at diagnosis (M = 19.45, SD = 11.70) Comorbidity: Depression (28.53%), Anxiety (27.83%), Bipolar disorder (6.61%), Schizophrenia (1.38%), EUPD (4.15%), SUD (15.49%) Without ADHD 67.9% Male Age at SA (M = 24.13, SD = 10.95) Age at diagnosis (M = 21.67, M = 15.38) Comorbidity: Depression (24.9%), Anxiety (22.69%), Bipolar Disorder (4.17%), Schizophrenia (4.87%), EUPD (2.45%), SUD (8.93%) | NPR ICD-10 | NPR and ICD codes (observational) Lifetime | No ADHD SAB: 2066 (8.4%) ADHD SAB: 2397 (12.6%) |
Hooijer & Sizoo (2020) | The Netherlands | Cross-sectional | Clinical 74 Autistic | - | 60.8% Male Age range 23–42.3 (Mdn = 28.5) IQ unknown (recruited through services for adults with average or higher intelligence) Comorbidity: Depression (33.8%), Anxiety (16.2%), PTSD (4.1%), OCD (5.4%), Personality Disorder (6.8%), Substance use (6.8%) | ADI-R Education and mental health records DSM-IV | BSS (Dutch; self-report) SI: Past week SA: Lifetime | SI: 52 (70.3%) SAB: 21 (28.4%) |
Hu et al. (2019)2 | Taiwan | Cross-sectional | Clinical 219 Autistic | - | 87.7% Male Age range 11–18 (M = 13.7, SD = 2.1) IQ range 80–127 (M = 92.4, SD = 10.9; WISC-IV) Comorbidity: Measured symptoms of Depression, Anxiety, ADHD and ODD | Formal diagnosis SRS (Chinese) DSM-V | KSADS-E—suicidality module (self-report) Past 12 months | 45 (20.5%) |
Jackson et al. (2018) | US | Cross-sectional | Nonclinical 56 Autistic | - | 46.4% Male Age range 18–57 (M = 22.98, SD = 6.01) Age range of diagnosis 3–38 IQ unknown (post-secondary students) Comorbidity: Depression (35.7%), GAD (33.9%), OCD (7.1%), Bipolar Disorder (5.4%), ADHD (23.2%) | AQ-10 Self-identified formal diagnosis | SBQ-R (self-report) Lifetime | SI: 11 (20%) SP: 22 (40%) SAB: 8 (14.5%) |
Moseley et al. (2020) | UK | Cross-sectional | Nonclinical 102 Autistic (77 Self-harmers/ 25 Non-self-harmers) | - | 28.4% Male Age range 54 (M = 42.26, SD = 13.91) Age at diagnosis (M = 34, SD = 17.2) IQ unknown (educated to at least GCSE/ late diagnosis corroborates cognitive level) Comorbidity: Depression (59.8%), Anxiety Disorders (GAD, social anxiety, OCD, specific phobias, PTSD; 53%), ADHD (13%), SH (75.5%) Employed: full-time (50%), voluntary (11.8%) | Self-identified formal diagnosis | SBQ-R (self-report) Lifetime Item "Have you ever thought about or attempted to kill yourself?" | SI: 30 (29.4%) SP: 36 (35.3%) SAB: 29 (28.4%) |
Moses (2018) | US | Cross-sectional | Nonclinical 159 Autistic | 10,330 TD/ 2873 youth with ≥ 1 disability | Information for whole “disabled” sample 49.4% Male Age 12–18 + (M = 15.9, SD = 1.2) IQ unknown (self-report used, high school students) Comorbidity: ≥ 1 type of disability (Emotional/ Mental health problems, Autism Spectrum, Hearing impairment, Vision impairment, Physical/ Mobility, Learning disability, Speech/ language problem, health problem, ADHD) | Self-identified | Unstandardised survey (self-report) Past 12 months “During the past 12 months, have you attempted to kill yourself?” (No; Yes, 1 time; Yes, more than 1 time) | SAB: 29 (18.2%) |
Mukaddes & Fateh (2010) | Turkey | Cross-sectional | Clinical 37 Autistic | - | 86.5% Male Age range 6–20 (M = 10.9, SD = 4.5) IQ range 90–139 (M = 116, SD = 14; WISC-R) Comorbidity: MDD (29%), GAD (5.4%), OCD (32%), Bipolar Disorder (8%), Eating Disorder (2.7%), Substance use (2.7%), ADHD (45%) Employed: voluntary (44%) | Developmental history Psychiatric interviews DSM-IV | Unstandardised clinician led interview (self-report) Unspecified | SAB: 6 (16%) |
Paquette-Smith et al. (2014) | Canada | Cross-sectional | Nonclinical 56 Autistic | - | 44% Male Age range 18–61 (M = 34.5, SD = 11.2) IQ unknown (diagnosed AS) Comorbidity: Depression (88%), Anxiety (94%), | AQ Self-identified formal diagnosis | Unstandardised (self-report) Unspecified Asked if they had ever attempted suicide | SAB: 18 (36%) |
Pelton et al. (2020) | UK | Cross-sectional | Nonclinical 350 Autistic | 339 Non-autistic | 35.4% Male Age range 18–90 (M = 41.91, SD = 13.59) IQ unknown (AQ requires average or above average intelligence) Comorbidity: ≥ 1 mental health condition (68.6%) Employed: full-time (30.3%) | AQ-S Self-identified formal diagnosis | SBQ-R (self-report) Lifetime | SI: 55 (16.1%) SP: 140 (40.9%) SAB: 131 (38.3%) |
Pilunthanakul et al. (2021) | Singapore | Cross-sectional | Clinical 101 Autistic | - | 87.1% Male Age range 9—18 (M = 14.6, SD = 2.3) IQ unknown (co-occurring ID excluded) Comorbidity: MDD (19%) | Formal diagnosis DMS-V ICD-10 | PHQ-9 (self-report AND informant-report) SI: Past month SA: Lifetime Items "has had serious thoughts about ending life in the past month" and "has made a suicide attempt at least once in whole life" | Self-report SI: 17 (16.8%) Parent-report SI: 9 (8.9%)2 Self-report SAB: 23 (22.8%) Parent-report SAB: 14 (13.9%)2 |
Raja et al. (2011) | Italy | Retrospective chart review | Clinical 19 Autistic | - | 94.7% Male Age range 18—56 (M = 29.84, SD = 10.39) IQ (M = 88.74, SD = 14.59; ID removed and recalculated by VN) Comorbidity: Schizophrenia (63.2%), Alcohol abuse (15.8%), Mania with psychotic signs (5.3%), Depression (21.1%), OCD (10.5%) | Clinical assessments Medical records Psychiatric interviews DSM-IV-TR | Unstandardised (self-report) Past month Asked whether they had: a) wished to die, b) thought about suicide in general, c) thought about methods for possible suicide, d) attempted suicide or self-harmed in any way | SI: 37 (48%) SP: 9 (12%) SAB: 1 (1%)2 |
Ryden et al. (2008)2 | Sweden | Cross-sectional | Clinical 6 Autistic | 35 Non-autistic with BPD | 0% Male Age (M = 31.2, SD = 8.89) IQ (M = 98.7, SD = 18.8; WAIS-III) Comorbidity: BPD (100%), MDD, Panic disorder, PTSD, GAD, Eating disorder, Bipolar Disorder, OCD, Psychotic episodes (% unknown) Employed: 16.7% | ASDI FTF A-TAC DSM-IV | SUAS (self-report) Lifetime | + 5 SA: 3 (50%) |
Sharpley et al. (2016) | Australia | Cross-sectional | Nonclinical 39 Autistic | - | 0% Male Age range 6–17 (M = 10.1, SD = 2.7) IQ threshold > 70 (WASI-II) | ADOS-2 DSM-IV-TR DSM-V | CASI-MDD (self-report) Unspecified Item 28 "I talk about dying and killing myself" | SI: 14 (35.8%) |
Shtayermman (2020) | US | Cross-sectional | Nonclinical 14 Autistic | - | 100% Male Age range 15–24 (M = 16.6, SD = 1.5) IQ unknown (diagnosed AS) Comorbidity: MDD (28.6%), GAD (15.4%) | Self-identified formal diagnoses DSM-IV-TR | SIQ Adolescent version (self-report) Past month | SI: 3 (21.4%) |
Shtayermman (2008) | US | Cross-sectional | Nonclinical 10 Autistic | - | 90% Male Age (M = 19.7, SD = 3.0) IQ unknown (diagnosed AS) Comorbidity: MDD (20%), GAD (30%) Employed: 40% | KADI | SIQ (self-report) Past month | SI: 5 (50%) |
South et al. (2020) | US | Cross-sectional | Nonclinical 26 Autistic (previous diagnosis) 48 Possibly autistic (traits) | - | 0% Male Age range 18–49 (M = 25.42, SD = 7.25) IQ range 83–140 (M = 114.8, SD = 11.12; FSIQ-2) Comorbidity: Mild/great severity of depression (76%), Mild/great severity of anxiety (81%) Employed: part-time (66.2%), full-time (6.8%) | ADOS AQ BAPQ SRS-2 | SBQ-R (self-report) Lifetime SI: Past 12 months | Autistic SBQ-R ≥ 8: 13 (50%) SI: 10 (39%) SP: 13 (50%) SAB: 4 (15.4%) Possibly Autistic SBQ-R ≥ 8: 17 (35.4%) SI: 19 (40%) SP: 9 (19%) SAB: 8 (16.7%) |
Storch et al. (2013) | US | Cross-sectional | Clinical 102 Autistic | - | 77% Male Age range 7–16 (M = 10.55, SD = 2.31) IQ threshold ≥ 70 Comorbidity: Depression (13.7%), GAD (74.5%), PTSD (5.9%), OCD (35.3%) | ADI-R ADOS DSM-IV-TR | ADIS-IV-C/P–Major Depressive Modules (self-report AND informant-report) SI/SP: Current SA: Lifetime | Child-report SI: 13 (13%) Parent-report SI: 12 (12%) Child-report SP: 9 (9%) Parent-report SP: 5 (5%) Child-report SAB: 1 (1%) Parent-report SAB: 1 (1%) |
Strang et al. (2021) | US | Cross-sectional | Both & TGNC 54 Autistic (27 Cisgender; 27 Transgender) 13 Possibly utistic (Transgender subthreshold autism) | 26 SAAB and age matched transgender allistic | Cisgender Autistic 59% Male Age range 13—21 (M = 16.42, SD = 1.9) IQ (M = 53.91, SD = 9.33; Matrix reasoning) Transgender Autistic 59% Male; 41% AMAB Age range 13—21 (M = 17.37, SD = 2.08) IQ (M = 112.73, SD = 15.89; WASI-2, WISC-5, WAIS-5) Transgender Possibly Autistic 62% Male; 38% AMAB Age range 13—21 (M = 16.99, SD = 2.14) IQ (M = 117.54, SD = 17.4; WASI-2, WISC-5, WAIS-5) | ADI-R ADOS-2 DSM-IV | ASEBA-YSR (self-report) Past 6 months Item 91 "I think about killing myself" | Autistic Cisgender SI: 7 (25.9%) Transgender SI: 15 (55.5%) Possibly Autistic Transgender SI: 9 (69.2%) |
Strauss et al. (2021) | Australia | Cross-sectional | Nonclinical & TGNC 172 Autistic | 687 Non-autistic Transgender | 38.8% Male Age range 14–25 IQ unknown (self-report used) Comorbidity: Depression (91.3%), Anxiety (93.6%), PTSD (57%), Eating Disorder (52.3%), Psychosis (51.2%), Personality Disorder (55.2%), SUD (41.3%), SH (85.1%) | Self-identified formal diagnosis | Unstandardised (self-report) Lifetime Information on reckless behaviour that purposely puts one’s life at risk, suicidal thoughts, and suicide attempts | SI: 135 (87.7%) SAB: 87 (57.2%) |
Takara & Kondo (2014a) | Japan | Case–control | Clinical 70 Autistic | 360 Non-autistic | 50% Male Age range 18–55 (M = 30.2, SD = 10.1) IQ unknown (without apparent intellectual problems; high school education or above; JART) Comorbidity: MDD (30%), Bipolar Disorder (22.9%%), Psychotic-like experiences (2.9%) | AQ (Japanese) Confirmation from parents Medical records DSM-IV-TR | Unstandardised (self-report) Unspecified Presence/absence of "suicide-related behaviours" confirmed by patients | SAB: 17 (24%) |
Takara & Kondo (2014b) | Japan | Case–control | Clinical 37 Autistic | 299 Non-autistic | 45.95% Male Age range 18–55 (M = 28.5, SD = 8.8) IQ unknown (without apparent intellectual problems; receiving mainstream education) Comorbidity: Depression (100%), Bipolarity (43.2%), Psychotic features (5.4%), Cluster B Personality Disorder (8.1%), Substance use (8.1%) Employed, homemaker or graduate: 75.7% | AQ (Japanese) Confirmation from parents Medical records DSM-IV | Unstandardised (observational) Unspecified Patients visiting outpatient clinic after suicide attempts | SAB: 9 (24.3%) |
Umeda et al. (2021) | Japan | Cross-sectional | Nonclinical 113 Possibly autistic (traits) | 2227 assessed for ASC/ 2297 assessed for ADHD | 7.1% Male Age range 20–75 IQ unknown (AQ requires average or above average intelligence) Comorbidity: MDD (6.2%), Dysthymia (0.9%), Anxiety (7.1%), Bipolar (0.5%), Substance use (15.6%) Employed: 4.9% | AQ-10 (Japanese) DSM-IV | Unstandardised (self-report) Lifetime Asked whether they had ever seriously thought about committing suicide | SI: 17 (15%) |
Wijnhoven et al. (2019) | The Netherlands | Cross-sectional | Clinical 93 Autistic | - | 76.3% Male Age 8–15 (M = 11.15, SD = 1.98) IQ (M = 102.16, SD = 18.14) | ADOS DSM-V | Child Depression Inventory (CDI-2) Dutch version Current Item 9 “I do not think about killing myself/ I think about killing myself but would not do it/ I want to kill myself” | SI: 31 (34.4%) |
Zhou et al. (2018) | China | Cross-sectional | Nonclinical 39 Possibly autistic (traits) 2780 students | - | 41.03% Male Age range 18–30 IQ unknown (college students) Comorbidity: Depression (53.8%), Mild anxiety (5.1%), OCD (71.8%) | AQ (Chinese) | Unstandardised (self-report) Unspecified Asked about suicide ideation, suicide plans, and suicide attempts (e.g. Do you have, or did you ever have a suicide plan?) | SI: 12 (30.8%) SP: 4 (10.3%) |
Meta-analysis
Moderator analysis
Subgroups | k | Prevalence (95% CI) | Heterogeneity Analysis | Between-subgroups Differences | |||||||
---|---|---|---|---|---|---|---|---|---|---|---|
p | QE | df | p | τ2 | I2 | QM | df | p | |||
Suicidal Ideation | |||||||||||
Group | |||||||||||
Autistic | 27 | .3607 (.2824; .4390) | < .001 | 693.67 | 26 | < .001 | .038 | 96.3% | 1.45 | 1 | .228 |
Possibly Autistic | 10 | .2872 (.1969; .3775) | < .001 | 69.74 | 9 | < .001 | .018 | 87.1% | |||
Age Group | |||||||||||
Youth (< 20 years) | 18 | .3082 (.2159; .4006) | < .001 | 386.94 | 17 | < .001 | .035 | 95.6% | 1.05 | 1 | .307 |
Adult (≥ 20 years) | 19 | .3738 (.2887; .4588) | < .001 | 431.37 | 18 | < .001 | .031 | 95.8% | |||
Geographical Location | |||||||||||
Asia | 8 | .2207 (.1732; .2681) | < .001 | 21.32 | 7 | .003 | .003 | 67.2% | 12.79 | 3 | .005 ** |
Europe | 16 | .3639 (.2627; .4651) | < .001 | 396.97 | 15 | < .001 | .038 | 96.2% | |||
North America | 10 | .3209 (.2050; .4369) | < .001 | 54.44 | 9 | < .001 | .027 | 83.5% | |||
Oceania | 3 | .5485 (.2972; .7998) | < .001 | 40.89 | 2 | < .001 | .046 | 95.1% | |||
Setting | |||||||||||
Clinical | 11 | .3523 (.2171; .4875) | .047 | 93.8% | 1.62 | 2 | .444 | ||||
Nonclinical | 23 | .3220 (.2484; .3956) | < .001 | 673.11 | 22 | < .001 | .029 | 96.7% | |||
Both | 3 | .4902 (.2382; .7422] | .039 | 79.8% | |||||||
TGNC Sample | |||||||||||
Yes | 4 | .6378 (.4808; .7949) | < .001 | 13.56 | 3 | .004 | .018 | 77.9% | 14.81 | 1 | < .001 *** |
No | 33 | .3087 (.2500; .3673) | < .001 | 561.28 | 32 | < .001 | .025 | 94.3% | |||
Suicidality Measure | |||||||||||
Suicidality | 13 | .3429 (.2368; .4491) | < .001 | 197.64 | 12 | < .001 | .034 | 97.0% | 5.95 | 2 | .051 |
General | 16 | .2670 (.2011; .3330) | < .001 | 69.12 | 15 | < .001 | .014 | 78.3% | |||
Unstandardised | 8 | .4709 (.3123; .6295) | < .001 | 234.63 | 7 | < .001 | .046 | 93.9% | |||
Type of Report | |||||||||||
Self | 33 | .3626 (.2945; .4306) | < .001 | 740.70 | 32 | < .001 | .034 | 71.8% | 14.38 | 1 | < .001 *** |
Informant | 4 | .1950 (.1414; .2486) | < .001 | 10.65 | 3 | .014 | .002 | 95.7% | |||
Risk of bias | |||||||||||
Low risk | 6 | .3651 (.2874; .4427) | < .001 | 16.26 | 5 | .006 | .006 | 69.2% | 0.28 | 1 | .594 |
Any risk (unclear or high) | 28 | .3352 (.2576; .4129) | < .001 | 817.93 | 27 | < .001 | .040 | 96.7% | |||
Suicide Plansª | |||||||||||
Group | |||||||||||
Autistic | 8 | .2606 (.1421; .3791) | < .001 | 254.18 | 7 | < .001 | .027 | 97.2% | 2.97 | 1 | .085 |
Possibly Autistic | 4 | .1386 (.0665; .2108) | < .001 | 10.25 | 3 | .017 | .004 | 70.7% | |||
Age Range | |||||||||||
Youth (< 20 years) | 2 | .0789 (.0390; .1188) | < .001 | 0.23 | 1 | .628 | 0 | 0.0% | 10.87 | 1 | .001 ** |
Adult (≥ 20 years) | 10 | .2492 (.1561; .3422) | < .001 | 251.74 | 9 | < .001 | .020 | 96.4% | |||
Geographical Locationb | |||||||||||
Europe | 5 | .2646 (.1490; .3802) | < .001 | 77.14 | 4 | < .001 | .016 | 94.8% | 0.15 | 1 | .701 |
North America | 5 | .2238 (.0511; .3966) | .011 | 59.96 | 4 | < .001 | .036 | 93.3% | |||
Suicidality Measure | |||||||||||
Suicidality | 8 | .2850 (.1807; .3893) | < .001 | 248.31 | 7 | < .001 | .020 | 97.2% | 13.12 | 2 | .001 ** |
General | 2 | .0789 (.0390; .1188) | < .001 | 0.23 | 1 | .628 | 0 | 0.0% | |||
Unstandardised | 2 | .1117 (.0544; .1690) | < .001 | 0.06 | 1 | .814 | 0 | 0.0% | |||
Risk of bias | |||||||||||
Low risk | 4 | .2762 (.1727; .3796) | < .001 | 10.60 | 3 | < .001 | .008 | 71.7% | 1.28 | 1 | .258 |
Any risk (unclear or high) | 8 | .1890 (.0788; .2992) | < .001 | 209.08 | 7 | < .001 | .024 | 96.7% | |||
Suicide Attempts and Behaviours | |||||||||||
Group | |||||||||||
Autistic | 26 | .2227 (.1689; .2765) | < .001 | 816.84 | 26 | < .001 | .017 | 96.8% | 1.31 | 1 | .253 |
Possibly Autistic | 4 | .3497 (.1386; .5608) | .001 | 32.12 | 3 | < .001 | .043 | 90.7% | |||
Age Group | |||||||||||
Youth (< 20 years) | 9 | .1916 (.0891; .2941) | < .001 | 227.86 | 8 | < .001 | .028 | 96.5% | 1.41 | 1 | .235 |
Adult (≥ 20 years) | 22 | .2643 (.2019; .3267) | < .001 | 663.16 | 21 | < .001 | .019 | 96.8% | |||
Geographical Location | |||||||||||
Asia | 5 | .1700 (.0923; .2478) | < .001 | 14.40 | 4 | .006 | .005 | 72.2% | 6.91 | 3 | .075 |
Europe | 16 | .2907 (.2156; .3658) | < .001 | 604.82 | 16 | < .001 | .021 | 97.4% | |||
North America | 7 | .1632 (.0862; .2401) | < .001 | 80.27 | 6 | < .001 | .009 | 92.5% | |||
Oceania | 2 | .2581 (− .2249; .7410) | .295 | 149.95 | 1 | < .001 | .121 | 99.3% | |||
Setting | |||||||||||
Clinical | 11 | .1880 (.1154; .2606) | < .001 | 119.06 | 10 | < .001 | .012 | 91.6% | 2.13 | 1 | .144 |
Nonclinical | 20 | .2680 (.1987; .3374) | < .001 | 755.19 | 19 | < .001 | .023 | 97.5% | |||
TGNC Sample | |||||||||||
Yes | 2 | .2966 (− .1174; .7106) | .160 | 38.5 | 1 | < .001 | .087 | 97.4% | 0.09 | 1 | .768 |
No | 28 | .2372 (.1846; .2898) | < .001 | 789.80 | 28 | < .001 | .018 | 96.5% | |||
Suicidality Measure | |||||||||||
Suicidality | 16 | .2439 (.1897; .2980) | < .001 | 541.89 | 15 | < .001 | .010 | 96.1% | 0.07 | 2 | .963 |
General | 6 | .2340 (.0344; .4336) | .022 | 102.18 | 5 | < .001 | .058 | 95.1% | |||
Unstandardised | 9 | .2601 (.1418; .3784) | < .001 | 207.08 | 8 | < .001 | .029 | 97.2% | |||
Type of Report | |||||||||||
Self | 27 | .2506 (.1911; .3101) | < .001 | 668.54 | 26 | < .001 | .022 | 96.1% | 0.71 | 1 | .399 |
Other | 4 | .1923 (.0706; .3140) | .002 | 221.36 | 3 | < .001 | .014 | 98.6% | |||
Risk of bias | |||||||||||
Low risk | 6 | .1876 (.1011; .2740) | < .001 | 302.95 | 5 | < .001 | .010 | 98.3% | 1.45 | 1 | .228 |
Any risk (unclear or high) | 23 | .2538 (.1894; .3182) | < .001 | 585.11 | 22 | < .001 | .022 | 96.2% |
Covariates | k | Coefficient (95% CI) | SE | z | Heterogeneity Analysis | Test of Moderators | |||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
QE | df | p | τ2 | I2 | QM | df | p | R2 | |||||
Suicidal Ideation | |||||||||||||
Male (%) | 36 | − .145 (− .370; .081) | .115 | − 1.258 | 823.245 | 34 | < .001 | .032 | 95.09% | 1.5814 | 1 | .207 | 2.07% |
Year of Publication | 37 | .007 (− .007; .021) | .007 | 0.950 | 840.160 | 35 | < .001 | .033 | 95.27% | 0.9023 | 1 | .342 | 0.00% |
NOS Overall Score | 34 | − .010 (− .056; .035) | .023 | − 0.451 | 709.112 | 32 | < .001 | .034 | 95.59% | 0.2037 | 1 | .652 | 0.00% |
Suicide Plans | |||||||||||||
Male (%) | 12 | − .404 (− .722; − .085) | .162 | − 2.486 | 106.626 | 10 | < .001 | .013 | 92.00% | 6.1805 | 1 | .013 * | 35.54% |
Year of Publication | 12 | .021 (− .013; .054) | .017 | 1.206 | 262.725 | 10 | < .001 | .020 | 94.64% | 1.4549 | 1 | .228 | 3.64% |
NOS Overall Score | 12 | .035 (− .014; .084) | .025 | 1.397 | 238.824 | 10 | < .001 | .019 | 94.90% | 1.9514 | 1 | .162 | 7.09% |
Suicide Attempts and Behaviours | |||||||||||||
Male (%) | 29 | − .106 (− .301; .090) | .100 | − 1.061 | 693.523 | 27 | < .001 | .021 | 99.51% | 1.1266 | 1 | .289 | 2.53% |
Year of Publication | 31 | .010 (− .006; .027) | .008 | 1.127 | 856.604 | 29 | < .001 | .020 | 99.44% | 1.4798 | 1 | .224 | 0.53% |
NOS Overall Score | 29 | − .008 (− .039; .023) | .016 | − 0.519 | 888.396 | 27 | < .001 | .020 | 99.46% | 0.2693 | 1 | .604 | 0.00% |