Suicidal and self harming behaviours may be distinct

Classifying the method as well as the motivation of self harm is important since the physiological mechanisms lead to different perceived and actual outcomes.¹ If the motivation is truly suicidal, a non-fatal outcome is unsuccessful, but where the motivation is not suicidal, death is accidental.

Overdoses of drugs or poisons are more likely to be lethal and, if unsuccessful, to result in hospital admission, whereas self harm involving physical injury such as cutting or hitting an inanimate object is more commonly encountered in the community.

Suicide numbers in studies can be increased by including people who injure themselves using highly painful methods with low lethality, but suicide studies require differentiation between these groups to retain validity. If self harm patients who die accidentally are included this will have a skewing effect on postmortem studies of suicide.

In our clinical practices in the community we recognise many patients who regularly use low lethality, high pain methods such as cutting, scratching, or other physical trauma to modify mood. We have previously hypothesised an aetiology for this self harm based on an imbalance of endogenous opioids² and have developed a treatment. Reductions in self harm behaviours were achieved by using low frequency transcutaneous electrical nerve stimulation ((TENS)³ for a limited time, during which subsequent resolution of self harm behaviour and urges was achieved by using psychotherapy (unpublished data). In these cases we assumed a psychological stimulus for the enduring opioid imbalance and used Shapiro's concept of adaptive information processing to address the root problems with trauma-specific eye movement desensitisation and reprocessing.⁴