Blunted defensive conditioned responses in adolescents with non- suicidal self-injury behaviors

Relief is a positive emotional state that arises following the cessation of painful stimuli. Adolescents with mental health problems frequently engage in non-suicidal self-injury (NSSI). NSSI has for long been postulated as regulatory mechanism for relieving intense aversive emotions. Although NSSI is hypothesized to result from a learning process, experimental evidence remains scarce. In this study, we tested whether adolescents suffering from NSSI have enhanced relief-learning as compared to healthy adolescents. Fifty-five female adolescents underwent classical conditioning during which one shape (conditioned stimulus, _pain CS) predicted a mild painful stimulation, another shape ( _relief CS) followed the pain and therefore was presented upon the moment of relief, and a third shape (CS-) was not associated with pain. Adolescent patients did not differ in their relief-related responses to the healthy adolescents, but they showed blunted defensive responses (lower physiological responses to _pain CS and no discriminative verbal responses between _pain CS and CS-). Relief-learning appears to be intact in adolescents with NSSI, whereas defensive responses during pain-learning was attenuated. Future studies should examine the impact of relief on instrumental learning to better elucidate the shift from healthy responses to persistent maladaptive instrumental behavior such as NSSI.