Pain Avoidance and Its Relation to Neural Response to Punishment Characterizes Suicide Attempters with Major Depression Disorder.

Diminished neural responses to punitive stimulus related to high level of pain avoidance may be biomarkers in distinguishing patients with history of suicide attempts from those without such histories. Outpatients with Major Depression Disorder (MDD, n=44) and healthy controls (HCs, n=28) were administered the Beck Depression Inventory-I (BDI-I), the Three-Dimensional Psychological Pain Scale (TDPPS), and the Beck Scale for Suicide Ideation (BSS), and then patients were allocated to two groups: suicide attempts (MDD-SA, n=12) and suicidal ideation (MDD-SI, n=32). All participants were required to complete the measurements and performed the Monetary Incentive Delay (MID) task with recording of electroencephalography synchronously. The MDD-SA group scored higher in the BDI-I, total TDPPS, pain avoidance subscale, and BSS-W scores than the MDD-SI and healthy control groups. Pain avoidance subscale scores had the highest correlations with SA than other inventory scores. The P3 elicited by negative feedback under punitive condition was significantly larger than those of reward and neutral conditions in the MDD-SA group, whereas no significant differences were found between the MDD-SI and HC groups. The P3 elicited by punitive and reward cues was negatively correlated to the total TDPPS and pain avoidance scores, and the P3 elicited by positive feedback in reward and punitive conditions was negatively correlated to the total TDPPS and painful feeing scores. Pain avoidance is a strong behavioral index in distinguishing suicide attempters from suicide ideators. The P3 patterns elicited by punitive cue and feedback may represent psychological pain processing which contribute to suicide act.