Individuals who were physically, sexually, or emotionally maltreated as children are more likely to engage in nonsuicidal self-injury (NSSI), new research shows.
Researchers analyzed 71 studies of the possible association between NSSI and childhood maltreatment, including physical, sexual, and emotional abuse, as well as physical and emotional neglect.
Overall, childhood maltreatment was found to be associated with NSSI, as were the other subtypes of childhood abuse. The association was not found in the case of childhood emotional neglect, in which studies were more likely to be subject to publication bias.
The connection was more strongly evident in community than clinical samples.
"One of the important take-home messages of the study is not to neglect emotional abuse, which is often given less weight than physical abuse," said corresponding author Richard L. Liu, PhD, assistant professor of psychiatry and human behavior, Alpert Medical School of Brown University, Providence, Rhode Island.
"If you have a patient engaging in self-injury, it is important to inquire into childhood maltreatment, current or past, and if you have a patient who was maltreated as a child, you should find out whether the patient might be self-injuring," he told Medscape Medical News.
The study was published online November 28 in Lancet Psychiatry.
Strong Predictor of Suicide Attempts
There is a "paucity" of empirically supported treatments for NSSI, the authors note.
The implications of this lack of studies are serious, given that NSSI is a "stronger predictor of suicide attempts than is a past history of suicidal behaviour." There is therefore a "pressing need" to clarify potential underlying factors to "inform the development of future prevention and intervention strategies," they write.
The current review was designed to systematically analyze childhood maltreatment and its subtypes in association with NSSI, to evaluate and quantify the strength of these associations after accounting for covariates, and to examine the potential mediators and moderators of this association.
"We especially wanted to look at emotional abuse, which has been understudied because it has traditionally been seen as less damaging than physical abuse," Dr Liu said.
To investigate the association, the researchers selected 71 of a total of 938 studies of childhood abuse and NSSI.
To be included, studies were required to systematically assess any form of childhood maltreatment (defined as maltreatment occurring before age 18 years) distinct from other adverse childhood experiences and to assess NSSI separately from other outcomes, such as suicidality and other risky behaviors.
An assessment of univariate associations (n = 19,537 participants, consisting of adolescents and adults; mean age, 15.17 and 28 years, respectively) found that overall, childhood maltreatment was positively associated with NSSI (odds ratio [OR], 3.42; 95% confidence interval [CI], 2.74 - 4.26; P < .0001).
When multivariate associations were assessed, overall maltreatment was found to be associated with NSSI in analyses that included all available covariates (OR, 2.79; 95% CI, 2.15 - 3.63; P < .0001).
In analyses that adjusted for covariates, all maltreatment subtypes were found to be associated with NSSI with respect to childhood sexual abuse (OR, 1.62; 95% CI, 1.38 - 1.90), physical abuse (OR, 1.73; 95% CI, 1.38 - 2.17), and emotional abuse (OR, 1.86; 95% CI, 1.42 - 2.44) (for all, P < .0001).
For childhood physical and emotional neglect, the associations, although still significant, were somewhat weaker (OR, 1.24; 95% CI, 1.00 - 1.52; P = 0.046, and OR, 1.17; 95% CI, 1.02 - 1.35; P = .027,).
In a further analysis that accounted for the high rates with which different forms of maltreatment co-occur, the researchers repeated and restricted the analyses to those that analyzed covariates for at least one maltreatment subtype.
They found that the results remained largely unchanged, with the exception of emotional neglect, which became nonsignificant.
Severity of overall maltreatment and three subtypes (sexual and physical abuse, and physical neglect) were associated with the severity of NSSI. This association did not hold for emotional neglect. There was an insufficient number of studies that investigated the association with emotional abuse.
The researchers identified several mediators between childhood maltreatment subtypes and NSSI, including general psychiatric morbidity for overall maltreatment, posttraumatic stress disorder, and dissociation for sexual abuse, personality dysfunction for emotional maltreatment and physical abuse, and dissociation for physical abuse.
Other mediators included academic self-efficacy, self-criticism, pessimism (for emotional abuse), and self-blame for physical abuse.
Associations were stronger in community than in clinical samples in moderator analyses. Although heterogeneity was higher for community than for clinical samples in the case of physical abuse, it was lower in community than clinical samples in the case of emotional abuse and neglect.
Emotional neglect was the only subtype of childhood maltreatment in which there was a potential publication bias in the studies.
"Collectively, these findings provide support for childhood maltreatment, and its specific subtypes, being associated with non-suicidal self-injury, although the available evidence is modest in the case of emotional neglect," the authors write.
They warn that, although the maltreatment subtypes share commonalities in their relationship with NSSI, "subtypes of childhood maltreatment should not be considered as a unitary construct."
"The mechanisms of correlation between NSSI and childhood maltreatment are complicated and related through different pathways that depend on the form of abuse," said Dr Liu.
"I suspect that sexual and physical abuse may largely be driven through the relationship with physical pain associated with self-injury," he noted.
"We all have a natural barrier to hurting ourselves, but the barrier is reduced when we are physically hurt by someone else. If a person has been physically hurt multiple times, that impediment to inflicting physical pain is reduced, and self-injury is more normalized and less foreign," he said.
Emotional abuse, on the other hand, might be related to NSSI through emotional dysregulation, he said.
He noted that the studies investigated whether there was a difference between the strength of relationship between childhood maltreatment and NSSI by age.
"The absence of such a relationship suggests that adults with childhood maltreatment were just as likely to engage in self-injury as teens, which speaks to the long-lasting effects of maltreatment in these individuals."
In an accompanying editorial, Lianne Schmaal, PhD, and Sarah Bendall, PhD, of Orygen, the National Centre of Excellence in Youth Mental Health, and the Center for Youth Mental Health, University of Melbourne, Australia, called the study "novel."
It "adds to the growing understanding of the extent of the impact of childhood maltreatment on a range of mental and physical health and other behavioral outcomes and the importance of tailoring services to take account of the unique needs of individuals who were maltreated in childhood."
They emphasize that it is "essential" to understand the individual's "context" for NSSI, such as association with trauma, because NSSI "might function to distract from severe trauma-related emotional distress or to reduce posttraumatic numbing and dissociation."
Dr Liu added that screening in school and clinical settings, including screening for emotional abuse, is important.
"If these forms of abuse do indeed have different pathways of association with NSSI, a different treatment focus would be warranted, especially given the gravity of NSSI, which is increasingly being found in research to be the strongest predictor of suicidal risk," he said.
The study was funded by the National Institute of Mental Health. The authors have disclosed no relevant financial relationships.
Lancet Psychiatry. Published online November 28, 2017. Abstract, Editorial
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Cite this: Childhood Maltreatment Drives Self-injury - Medscape - Dec 06, 2017.