A total of 16 published studies were found that presented empirical data on NSSID.
Four studies used the final DSM-5 13] criteria, while others used some or all of the earlier criteria 12], 15]. Of these, one based the empirical data on clinicians’ ratings 42] and two 43], 44] were new analyses of study populations already included 45], 46]. Ten studies included adolescents 14], 23], 44], 46]–52], of which two also included older children 47], 48]. Four studies included young adults 51]–54] (only or in addition to adolescents) and three were limited to adults only 43], 45], 55]. See Table 1 for empirical studies.
Table 1. Empirical studies of the nonsuicidal self-injury disorder diagnosis
NSSI disorder characteristics
Prevalence of NSSID in child and adolescent community samples ranged from 1.5 to 5.6%
47], 48]. In community samples of adolescents only, 3.1–6.7% met NSSID criteria 14], 46], as compared to 18.8% of those with an NSSI history 46] and 49.2% of those with repetitive NSSI 14]. Equivalent rates in a young adult community sample with repetitive NSSI were 37%
53]. Prevalence in adolescent and young adult clinical samples ranged from 36.9 to 50%
23], 49] while 46.2 to 78% 23], 50]–52] of those with an NSSI history met NSSID criteria. In most studies more girls than
boys met criteria (Table 1). The average age of onset for NSSI in those with NSSID ranged from 12.52 to 13.05 years
(SD 1.73–3.53) 23], 50], 52]. The most common methods were cutting, banging/hitting, severe scratching, carving
and scraping 23], 50], 53]. Several methods were reported, ranging from an average of 4.29–8 (SD 2.18–2.78)
methods 23], 46], 50]–53]. The functions most often endorsed by those who met NSSID criteria were affect regulation,
self-punishment and anti-dissociation/feeling-generation 23], 46], 50], 53]. In clinical studies of adolescents and young adults with NSSID, 69.2–83.3% 50], 51] reported having made a suicide attempt, and in one study 24.4% reported having done
so during the last month 23]. Among community adolescents who met criteria for NSSID, 20% reported that at least
one of their self-injuries during the last year was a suicide attempt 46]. Several of those with NSSID in clinical and community samples with recurrent NSSI
also had concurrent axis I diagnoses 23], 45], 50], 51], 53]. Mood disorders commonly co-occurred, with examples of 72.5% 53] and 79.5% 50] for depression. Anxiety disorders were also commonly reported (72.5–89%) 23], 51], 53], as was posttraumatic stress disorder (PTSD) with rates of 25.0–28.2% 50], 53]. In two studies of clinical adolescents with NSSID, 51.7% 23] and 20.5% 50] met criteria for BPD. High levels of emotional dysregulation 23], 53], low quality of life 52] and impairment 45], 52] have also been found in those meeting criteria for NSSID.
DSM-5 NSSI criteria
Criterion A
In a self-injuring sample of inpatient and intensive outpatient adolescents and young
adults, 85.5% endorsed criterion A, i.e., at least 5 days 52]. Rates of 76–77% were found in an outpatient clinical sample and also in a community
sample of repetitive NSSI 51], 53], whilst a considerably lower endorsement of criterion A (20.8%) was found in a self-injuring
adult community sample 55]. Of those who met NSSID criteria, 73.7% had performed NSSI ? 11 times during the
last year and 26.3% had done so 5–10 times. More girls than boys had performed NSSI ? five
times in this study of community adolescents 46]. Lengel and Mullins-Sweatt 42] asked 119 clinicians and NSSI experts to rate whether the NSSID criteria represented
prototypic cases/symptoms of a self-injuring patient and 85% considered that five
instances was prototypic. Absence of suicidal intent was endorsed as prototypic by
90%.
Criterion B
In one community study of adolescents 46], almost all (99.5%) of those with NSSID reported having engaged in NSSI with the
expectation of relieving an interpersonal difficulty or negative feeling, or of inducing
a positive feeling. A similarly high endorsement (87.2–87.7%) was found in inpatient
adolescents with NSSID 50], 52]. Engaging in NSSI for a purpose was also thought to be a prototypical symptom by
71.9% of clinicians and NSSI experts 42]. In one study 53] 79% of young adults with NSSI met criterion B, compared to 66.4% in an adult community
sample of self-injurers 55]. The earlier B criterion (current DSM-5 equivalent of B and C) was met by 97% of
self-injuring outpatient adolescents and young adults 51]. Empirical studies that used the final DSM-5 13] criteria and presented data for each subcriterion found B1 (relief) to be the most
common 52], 55]. In adolescents, B3 (positive feeling) was least commonly endorsed 52]. Criterion B2 (to relieve interpersonal problems) was more often endorsed in a clinical
sample including adolescents 52] than in an adult community sample 55]. In the study by Washburn and colleagues 52] patients rarely met criterion B without also meeting criterion C. Criterion B was
further found to be associated with interpersonal functions of NSSI 53]. Girls reported expectations of relief from negative feelings and thoughts more often
than boys 47].
Criterion C
Criterion C1 (interpersonal/psychological precipitant) was consistently met by nearly
all participants. Of adolescents with NSSID, 97.4–100% endorsed criterion C1 46], 50], 52]. In the study by Washburn and colleagues 52] there was an additionally high endorsement of criteria C2 (preoccupation) and C3
(urge). Of those who did not meet criteria for NSSID, very few failed to meet criterion
C. Criterion C1 was also significantly associated with psychopathology and impairment
52]. Of those with self-injury, 81–98% 23], 51]–53] met criterion C and 82.4% of self-injuring community adults met criterion C1 55]. Psychological precipitants were more commonly reported in girls 46], 47]. Negative emotions/thoughts prior to NSSI was considered a prototypic symptom by
87.5% of clinicians, while frequent urge and preoccupation to engage in NSSI was relatively
less so 42]. Similarly, preoccupation was reported by less than 50% of the adolescents with NSSID
in the study by In-Albon and colleagues 50], while frequent urge was endorsed by 89.7%.
Criterion D
In a study of young adults 53] 91% of self-injurers met criterion D, which refers to behaviors that are not socially
sanctioned. Eighty-eight percent of clinicians and NSSI experts thought this to be
a prototypic symptom 42].
Criterion E
In one study of clinical self-injuring adolescents and young adults, 43% failed to
meet NSSID criteria because they did not fulfill the distress or interference criterion
51]. The interviewers considered this criterion difficult to assess, since patients tended
to report that their self-harm was helpful rather than distressing or impairing. In
self-injuring samples, 41–64% met criterion E 51], 53]. In adolescents with NSSID, 76.8% 46] and 69.2% 50] reported that their NSSI caused them distress. However, a question whether adolescents
desired help for their NSSI received a 79.5% endorsement 50]. In Andover’s 55] adult sample, 8.8% of self-injurers endorsed interferences in functioning, while
60.8% wanted to stop engaging in NSSI. The most common interferences reported were
in academic and social (school) life 47], interpersonal relationships and schooling 46] and also leisure time 50]. More girls than boys acknowledged distress/impairment 46]. Criterion E had less than 50% endorsement as a prototypic symptom 42]. In a study of young adults, clinical characteristics such as emotion dysregulation,
BPD, symptoms of depression, anxiety and stress were most strongly associated with
criterion E, as were intrapersonal functions, and this criterion best distinguished
those with NSSID from those with NSSI without NSSID 53].
Criterion F
In a self-injuring sample of young adults, 80% met exclusion criterion F 53], as did 98.2% of adolescents 52]. Several of the studies using self-report measures did not assess this criterion
directly.
NSSI disorder versus NSSI, clinical controls and borderline personality disorder
NSSI disorder versus NSSI
Compared to those with NSSI not meeting NSSID criteria, those with NSSID reported
higher levels of psychopathology and significantly more interference in functioning
52], 53], 55], as well as more variety of NSSI methods 51]–53] (Table 2). The NSSID group endorsed significantly higher levels of automatic functions (emotion
relief, feeling generation) than the non-NSSID group 46], 53], 55], with average rates of automatic negative reinforcement of 2.43 (0.84) vs. 1.54 (0.81)
and automatic positive reinforcement 2.08 (0.71) vs. 1.33 (0.51) in inpatient adolescents
50]; significantly higher levels of emotion dysregulation, 109.42 (21.79) vs. 94.26 (23.07)
53]; significantly higher levels of symptoms of depression, 18.68 (11.28) vs. 13.99 (9.86)
indicating moderate vs. mild/moderate symptoms; anxiety symptoms, 15.12 (9.81) vs.
9.31 (7.23) indicating severe vs. mild symptoms and stress, 20.65 (10.00) vs. 14.20
(8.04) indicating moderate vs. mild symptoms in young adults with recurrent NSSI 53]. There were also significantly higher levels of symptoms of depression, anxiety,
anger, posttraumatic stress and dissociation in community adolescents with NSSID compared
to those with NSSI not meeting NSSID criteria 44] and significantly more smoking and drug use 46]. Significantly more community adolescents with NSSID reported experiences of adversities
and maltreatment than adolescents with NSSI not meeting NSSID criteria 44], for example, bullying, 62.4 vs. 40.0%; emotional abuse, 77.4 vs. 40.8%; physical
abuse from an adult within the family, 38.7 vs. 16.0% and sexual abuse, 36.6 vs. 8.4%
44]. Suicide ideation, 1.40 (1.17) vs. 1.08 (1.18), was also significantly higher in
inpatient adolescents with NSSID compared to those with NSSI not meeting full criteria
52]. Concerning concurrent axis I diagnoses, significantly more young adults with NSSID
had PTSD, 25.0 vs. 10.4%; BPD, 45.0 vs. 19.4%; bipolar disorder, 20.0 vs. 6.0%; social
anxiety disorder, 37.5 vs. 19.4% and alcohol dependence, 40.0 vs. 17.9%, compared
to individuals with recurrent NSSI not meeting NSSID criteria 53]. Among inpatient adolescents with NSSID there were significantly higher levels of
BPD traits, 37.79 (11.35) vs. 33.38 (10.92) 52]. Importantly, the association between NSSID and psychopathology in the study by Gratz
and colleagues 53] remained significant when controlling for BPD.
Table 2. Group differences when comparing NSSID vs. NSSI; NSSID vs. clinical controls; NSSI
vs. BPD
NSSI disorder versus clinical controls
Significantly more inpatient adolescents with NSSID reported suicide ideation, 67.1
vs. 29.2% and suicide attempts, 24.4 vs. 8.6% 23], compared to clinical adolescents. Furthermore, significantly more inpatient adolescents
among those who met NSSID criteria had major depression, 79.5 vs. 30.0% 50]; anxiety disorder, 73.5 vs. 41.2%; mood disorder, 66.3 vs. 33.3%; bulimia, 18.3 vs.
0%; BPD, 51.7 vs. 14.9%; a higher total number of axis I diagnoses, 4.23 (2.52) vs.
2.35 (1.76) and reported loneliness compared to clinical controls 23]. Adolescents with NSSID also had significantly more internalizing and externalizing
symptoms 50]; higher levels of emotion dysregulation and general psychopathology and impairment
than clinical controls 23], 50]. The association between NSSID and clinical impairment in the study by Glenn and
Klonsky 23] remained significant when controlling for BPD. An adult NSSID group also had significantly
more general psychopathology and impairment 43], 45]; more symptoms of anxiety and depression 45]; more suicide attempts and ideation; were more often victims of abuse; had more previous
treatment 45], ended therapy prematurely, had worse prognostic outcome after therapy than an axis
I clinical comparison group but showed larger decreases on ratings of severity of
illness from intake to termination as well as more improvement following therapy 43] (Table 2).
NSSI disorder versus borderline personality disorder
One study on adults distinguished potential NSSID from BPD. There were no differences
in comorbidity and functional impairment between the groups. The BPD group, however,
contained more women, 88 vs. 51% and reported higher rates of abuse, 54 vs. 28% 45]. The same sample was also used in a later study by Ward et al. 43], where those with NSSID showed greater improvement after treatment compared to intake
than those with BPD. In one study 50] 80% of adolescents who met NSSID criteria did not meet criteria for BPD. Glenn and
Klonsky 23] found that NSSID occurred independent of BPD. There was a significant overlap between
NSSID and BPD, but the diagnostic overlap between BPD and other disorders was similar
to that between BPD and NSSID. Odelius and Ramklint 51] also found that patients with NSSID had several comorbid diagnoses which were not
concomitant with BPD. Bracken-Minor and McDevitt-Murphy 54] compared BPD-positive and BPD-negative self-injuring young adults and found preliminary
support for a distinction, where those with BPD reported higher levels of emotion
dysregulation, 105.28 (22.95) vs. 88.31 (21.56) and functions of self-punishment,
3.90 (2.04) vs. 2.39 (2.12); anti-suicide, 2.41 (2.16) vs. 1.06 (1.87) and anti-dissociation,
2.38 (1.86) vs. 1.42 (1.73). Furthermore, the NSSI methods cutting and burning were
more often reported compared to those without BPD (Table 2).
Assessment of NSSI disorder
Several studies have assessed NSSID criteria indirectly with instruments not originally
developed for this purpose. The Clinician Administered Nonsuicidal Self-Injury Disorder
Index (CANDI) 53] and the self-report measure The Alexian Brothers Assessment of Self-Injury (ABASI)
52] were designed to assess and identify NSSID. The CANDI showed good interrater reliability.
The overall diagnostic agreement was 92%. There was a 100% agreement for criteria
A, B, C, D and F and 92% for criterion E. Furthermore, internal consistency was adequate
and there was support for construct validity. There was support for a two-factor solution
on the ABASI, with all items assessing criterion B and criterion C loading on respective
factor. Internal consistency was adequate. Item-total correlations showed that the
ABASI item for criterion B3 was weakly correlated with the NSSI severity score. Test–retest
reliability was moderate for the NSSID, good for criterion A and criterion C, but
poor for criterion B. Test–retest was good for ABASI NSSI severity scores and moderate
for criterion B and criterion C subscales. In-Albon and colleagues 50] constructed a clinical interview from the DSM-5 criteria which showed very good interrater
reliability. Fischer et al. 49] used a German version of the Self-Injurious Thoughts and Behaviors Interview (SITBI)
56] to identify NSSID and found moderate agreement in test–retest and very good interrater
reliability. They argued that NSSI may have been triggered in their sample by the
inpatient clinical setting, hence influencing test–retest results. Fischer et al.
49] suggested extending SITBI to include items on functional impairment and distress
to optimally match NSSID criteria.