Mechanisms mediating suicide related outcomes; child abuse, pain and self-injury.

Article in review: Schonfelder, A., Rath, D., Forkmann, T., Paashaus, L., Sengler, K., Teismann, T., Juckel, G. & Glaesmer H.  Is the relationship between child abuse and suicide attempts mediate by nonsuicidal self-injury and pain tolerance? (2020) Clin Psychol Psychother 2021 Jan DOI: 10.1002/cpp.2501

Summary: There is a growing body of evidence that has found that there is a link between the experience of child abuse and suicidal behaviour. Yet the underlying mechanisms for this association are unclear. This study has sought to help us better understand the relationship between the experience of sexual, emotional or physical abuse as a child to suicidal behaviour as an adult by considering the mediating impact of nonsuicidal self-injury and pain tolerance.  Understanding how these factors relate can only help us provide better, individualised responses for people at risk of suicide.

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Suicide risk and capability for suicide
Suicide risk may be considered through biological approaches, such as those related to serotonin dysfunction as well as the more commonly considered psychological theories. Suicide ideation is often described as a result of the presence of feelings of thwarted belongingness and being a burden to others. Suicidal thoughts may develop into suicidal behaviour when there is an increased pain tolerance and a decreased fear of death or pain. Pain tolerance is acquired through repeatedly experiencing painful and provocative events such as

• Self-injury
• Combat experiences
• Sexual and physical abuse

It is assessed through the application of pressure on a person’s finger and through a questionnaire to assess a person’s subjective pain response. People engaging in nonsuicidal self-injury (NSSI) have been found to have higher pain thresholds and pain endurance. NSSI is a strong predictor of suicidal behaviour.

Study participants and tools
The study involved 308 participants, (mean age 36.9 years, 53% female) with either acute suicide risk or recent suicide attempt. More than two-thirds of the group had experienced at least one physical, emotional or sexual abuse in childhood.

The assessment tools used were:

• Childhood Trauma screener- a retrospective self-screening tool to consider experiences of maltreatment during childhood
• The German version of the self-injurious thought and behaviours interview- a structured interview assessing presence, frequency and characteristics of self-harm
• German capability for suicide questions (GCSQ) – to measure pain tolerance, fearlessness of death and perceived suicide susceptibility
• Pressure Altimeter Wagner FDX 50- the application of constant pressure on the index finger of the dominant hand, with participants indicating pain threshold and pain tolerance

A formulaic statistical analysis of each data set was carried out to test the hypotheses that:

• All kinds of abuse are related to NSSI
• Physical and sexual abuse are both directly related to pain tolerance
• NSSI is related to suicide attempts
• Pain tolerance is related to suicide attempts
• All kinds of abuse are indirectly related to suicide attempts via NSSI and pain tolerance

Findings
The findings confirmed that, as suspected, there is a relationship between NSSI and suicide attempts, making it one of the strongest predictors for suicidal behaviour. This complemented findings of earlier studies that suggested that there any form of abuse as a child increasing chances of suicidality in adulthood, and with NSSI as a mediator. All types of abuse showed relationships with NSSI, which was connected to suicidal behaviour in almost all models, though findings were not all as expected. Of interest, the way in which pain was measured – with the GCSQ but not the algometer.
Mechanisms
This confirms that child abuse is a risk factor for engagement in NSSI. Child abuse is also indirectly linked to suicide attempts via NSSI. In this way, the results are not surprising. However, the authors found that pain tolerance did not show the predicted relationship with child abuse, NSSI or suicide attempts and indeed, emotional abuse was inversely related to pain tolerance. Several explanations for this finding are provided, child abuse is however indirectly linked to suicide attempts by NSSI. For this reason, NSSI should still be considered an important risk factor in suicide risk assessment. Of note, working to understand pain tolerance as a mediating factor to suicide is incredibly challenging, firstly due to variations in how pain s measured and secondly, the fluctuations in pain tolerance capability as influenced by the experience of interpersonal distress.