text: Stanley B, Sher L, Wilson S*et al.*Non-suicidal self-injurious behavior, 
  endogenous opioids and monoamine neurotransmitters.*J Affect*
  *Disord*2010;**124**:134–40.  Tsypes A, Owens M, Hajcak G*et al.*Neural reward responsiveness 
  in children who engage in nonsuicidal self-injury: an ERP study.*J*
  *Child Psychol Psychiatry*2018;**59**:1289–97. 
  
  Stephan KE, Manjaly ZM, Mathys CD*et al.*Allostatic self- 
  efficacy: a metacognitive theory of dyshomeostasis-induced 
  fatigue and depression. 
  *Front Hum Neurosci*2016;**10**: 
  550. 
  Turner BJ, Austin SB, Chapman AL. Treating nonsuicidal self-injury: 
  a systematic review of psychological and pharmacological inter- 
  ventions.*Can J Psychiatry*2014;**59**:576–85. 
  
  van der Venne P, Balint A, Drews E*et al.*Pain sensitivity and plasma 
  beta-endorphin in adolescent non-suicidal self-injury.*J Affect Dis-*
  *ord*2021;**278**:199–208. 