Table 1 Lists the studies that were found which explored to any degree the association between ADHD and self-harm and details some of the main points from each (nature of sample; the aim of the study and the main findings)

Ben-Yehuda et al. 2012[40]

232 ED referrals; 37 (15.9%) children and 195 (84.1%) adolescents.

To investigate the hypothesis that suicidal behaviour in children stems from a different diagnosis other than suicidal behaviour in adolescents.

Findings revealed a diagnostic difference between suicidal children and suicidal adolescents. An act of DSH or ideation was the presenting symptom of 232 ED referrals; this figure comprised 37 (15.9%) children and 195 (84.1%) adolescents. For children, the prevalent diagnoses were ADHD (43.2%), conduct disorders (21.6%), and adjustment disorders (16.2%). For adolescents, the prevalent diagnoses were adjustment disorders (28.7%) and conduct disorders (17.9%) (p < 0.001).

Children group – under 12 years old.

Adolescent group between 12-18 years.

Deane and Young (2012)[41]

8 female participants - 4 from the comorbid group (ADHD/CP; Astrid, Anna, Abigail, and Alison) and four from the control group. (All between 14 & 16 years of age at the time of the interviews).

To investigate the experience of girls growing up with cognitive and social disorders.

2 cases where there was a presentation of both ADHD and self-harm or attempted suicide - Anna and Abigail had attempted suicide and Alison had engaged in extensive self-harm. The authors found that Alison was able to make a clear link between her feelings of emotional isolation, behavioural problems and self-harming behaviour.

The association between ADHD and self-harm was not the focus of this paper.

DiScala et al. (1998)[42]

2 groups

To investigate the differences between hospital admitted injuries to children with pre-injury ADHD and injuries to those with no pre-injury conditions (NO).

Compared with the NO children, the children with ADHD were more likely to inflict injury to themselves (1.3% versus 0.1%).

1) all cases of paediatric trauma that had a pre-injury diagnosis of attention deficit or hyperactive disorder or both ADHD

They were more likely to sustain injuries to multiple body regions (57.1% versus 43%), to sustain head injuries (53% versus 41%), and to be severely injured as measured by the Injury Severity Score (12.5% versus 5.4%) and the Glasgow Coma Scale (7.5% versus 3.4%).

2) all cases of paediatric trauma with no pre-injury condition (NO).

ADHD patients (n = 240) to NO patients (n = 21 902), 5 through 14 years of age.

Dowson et al. (2007)[43]

59 adult patients (mean age: 30.6 years, range 9.8 years) with a DSM-IV diagnosis of ADHD.

To investigate the associations between questionnaire assessments of behavioural features of adults with ADHD and an aspect of neurocognitive performance which has been reported to be impaired in adults with ADHD.

Patients who reported a past history of ‘self-harm' (N = 33) had a significantly worse mean performance on both measures of SWM (p = 0.004, 0.003).

Dowson et al. (2010)[44]

73 male adults with DSM-IV ADHD (aged 18-65 years) and their informants. Impulsive externally directed aggression was endorsed in 29 of the 73 subjects and impulsive autoaggression in 34 subjects.

To investigate the associations between impulsive aggression and ADHD.

Adult ADHD-related impulsivity and hyperactivity predicted temper outbursts ⁄hitting people ⁄throwing, while self-reported adult ADHD-related inattention predicted threats ⁄actual self-harm.

Impulsive externally directed aggression was endorsed in 29 of the 73 participants and impulsive autoaggression in 34 participants.

Fulwiler et al. (1997)[45]

Inmates were classified as self-mutilators if they had inflicted objectively verifiable bodily injury without either the intent or wish to die (n = 16). Suicide attempters were de- fined as patients whose intention was to die (n = 15). Self-mutilators -mean age 30 years (SD = 7.2). Suicide attempters – mean age 34 years (SD =7.3).

To test the hypothesis that prisoners who injured themselves without intending to die would differ clinically from prisoners who had attempted suicide.

A logistic regression analysis incorporating childhood hyperactivity and affective disorder as covariates found that self-mutilators were 28 times more likely to report childhood hyperactivity.

The early onset of psychiatric symptoms in self-mutilators was also reflected in the fact that 75 percent (12/16) reported being diagnosed hyperactive as children, compared with only one of the attempters.

Goodman et al. (2008)[46]

AS group - age 8.38 (1.97) years (n = 24).

This study investigated mother and child’s aggression as well as child correlates of suicidal behaviour in two groups—assaultive/suicidal (AS) and assaultive-only (AO) —prepubertal psychiatric inpatients.

AS children were significantly more aggressive and suicidal, five times more likely to engage in serious assaultive behaviour, and almost six times more likely to be diagnosed with ADHD than their AO counterparts. Suicidal behaviour treated as a 5- point dimensional scale in the total sample was associated with child’s aggression, the presence of ADHD, maternal depression, and maternal state anger, but not with child’s depression. Child’s aggression mediated the relation between the presence of ADHD and suicidal behaviour in the total sample.

AO group - 8.74 (1.82) years (n = 19).

Hinshaw et al. (2012)[47]

Childhood-ascertained (6-12 years) girls with ADHD (ADHD; n = 140: combined type [ADHD-C] n = 93; inattentive type [ADHD-I] n = 47) plus a matched comparison group (n = 88). 10 year outcomes (age range 17-24 years; retention rate = 95%).

To investigate the 10-year outcomes in girls diagnosed with ADHD in childhood – outcomes investigated were symptoms (ADHD, externalising, internalising), substance use, eating pathology, self-perceptions, functional impairment (global, academic, service utilisation), self-harm (suicide attempts, self-injury), and driving behaviour.

Self-injury was found to be significantly more likely (OR = 4.4) in the ADHD-C group (51%) than the comparison group (19%).

Self-injury was also found to be more likely in the ADHD-C group compared to the ADHD-I group (29%; OR = 2.5).

These findings show that self-harmful behaviour predominated in the participants originally diagnosed with ADHD-C.

Hurtig et al. (2012)[48]

Sample derived from a population-based Northern Finland Birth Cohort 1986 (n = 9432). Based on the Schedule for Affective Disorders and Schizophrenia for School-Age Children, Present and Lifetime Version (Kiddie-SADS-PL) interview performed in a subpopulation (n = 457).

To investigate the effect of ADHD on suicidal or self-harm behaviour in adolescents from a general population sample.

Compared with adolescents without ADHD, those with ADHD had more suicidal ideation (57% versus 28%, p < 0.001) and DSH (69% versus 32%, p < 0.001).

Compared adolescents without ADHD (n = 169) and those with ADHD (n = 104).

Izutsu et al. (2006)[49]

239 boys (mean age = 14.16 years, SD = 0.67) & 238 girls (14.22, 0.68) from a junior high-school in Kanagawa, Japan

To investigate the status of DSH among junior high-school students, and investigate the relationship between DSH and substance use and childhood hyperactivity.

Overall, 8.00% and 27.70% of males and 9.30% and 12.20% of females reported self-cutting and self-hitting, respectively.

With respect to the association between DSH and childhood hyperactivity, comparisons of WURS scores between those with and without experience of problematic behaviours revealed that with all problematic behaviours in both genders, scores of those with experience were significantly higher than those without (p < 0.01 except for self-cutting in females, p < 0.05).

Lam (2002)[17]

158 with ADD and 46,962 non-ADD individuals between the ages of 16 and 19 years admitted to hospitals due to accidental or self-inflicted injuries in New South Wales, Australia during 1996 to 2000.

To investigate the following: What patient characteristics are associated with the diagnosis of ADD upon admission to the hospital? What types of injury are associated with the diagnosis of ADD among hospitalised young patients? What is the relationship between the diagnosis of ADD and the outcome of hospitalisation due to injury?

Significant association between different causes of injuries, in particular self-inflicted injuries and diagnosis of ADD were found.

Lam (2005)[50]

Children and adolescents between the ages of 5 and 15 years admitted to hospital owing to injuries in 2000. 111 individuals with ADD and 18,618 with no ADD.

To investigate the associations between intra-and interpersonal violence and related injuries and the diagnosis of ADD among children and young adolescents.

There were significant associations between suicide and self-harm, injuries owing to assault, and diagnosis of ADD. The odds for self-inflicted injuries were about 8.5 for children diagnosed with ADHD as compared with those without.

Lynch et al. (2006)[51]

12-15 year olds (selected from 8 secondary schools).

To investigate the prevalence rates of psychiatric disorders, suicidal ideation and intent, and parasuicide in a population of Irish adolescents in a defined geographical area.

Investigation of the association between ADHD and self-harm behaviours were not investigated in this paper.

Investigation of the association between ADHD and self-harm behaviours were not investigated in this paper.

In the ‘at-risk’ group, six (5.9%) had a diagnosis of ADHD and only three (3.2%) had a diagnosis of ADHD in the ‘not at-risk’ group. The estimated prevalence in the entire population (based on a weighted analysis) was 3.7% (95% CI = 0.7-6.7).

Semiz et al. (2008)[52]

105 adult male offenders with Structured Clinical Interview for Axis II Disorders (SCID-II)-based DSM-III-R APD. (Age 20–36 years, mean ± SD = 22.7 ± 2.9 years).

Two-fold:

92 per cent of the participants (n = 97) reported SIB. These included: self-cutting (82%), hitting (51%), burning (37%), and biting (14%). Sixty-five per cent (n = 68) of the subjects had received medical treatment for SIB, indicating the serious and persistent nature of these self-inflicted wounds.

(1) to define the relationship between DSM-III-R APD and PCL-R-based psychopathy scores with comorbid diagnosis of ADHD (ADHDc) and dimensional ADHD symptoms (ADHDd) in a group of male offenders.

(2) To examine the relationship of ADHD measures within the study population with SUD, SIB, and record of suicide attempts and criminal behaviours.

Number of ADHDd symptom criteria endorsed was significantly correlated with frequency of SIB (r = 0.32, p = 0.002). WURS total score was significantly correlated with frequency of SIB (r = 0.38, p < 0.001), number of suicide attempts (r = 0.28, p = 0.011), number of criminal behaviours (r = 0.26, p = 0.016), PCL-R total (r = 0.28, p = 0.016) and Factor 2 scores (r = 0.36, p = 0.002), and negatively correlated with age at onset of SIB (r = – 0.23, p = 0.023). CAARS total score was significantly correlated with frequency of SIB (r = 0.34, p < 0.001) and number of suicide attempts (r = 0.32, p = 0.007).

Wehmeier et al. (2008)[53]

Patients aged 6-17 years with ADHD treated with atomoxetine (target dose 1.2 mg/kg/day). 355 patients completed the 8-week treatment course & 260 patients completed the 24-week treatment course.

To measure changes in items on the PAERS that relate to emotional well-being of children and adolescents with ADHD during treatment with atomoxetine for up to 24 weeks from the perspective of the patient, the parent, and the physician.

421 ADHD patients were treated with atomoxetine - The ten items that reflect emotional well-being were grouped in five dimensions: depressed mood, self-harm, irritability/agitation, drowsiness, and euphoria. The scores of these dimensions decreased over time, both from a patient as well as from a parent and physician perspective.

Only the dimension self-harm was extremely low at baseline and stayed low over time.