The overall aim of this study is to begin establishing an effective treatment for individuals who engage in non-suicidal self-injury (NSSI), as there are currently no evidence-based treatments that directly target this problematic behavior. Existing treatments that have demonstrated initial promise in reducing NSSI consist of many skills embedded in complex programs; therefore, the skill(s) responsible for improvements in NSSI are not clear. Procedures that focus on one's emotions, particularly that aim to increase emotional awareness and engagement in cognitive reappraisal (i.e., a way of thinking that lessens emotions), may be critical in effective NSSI treatment. The specific goals of this study are to investigate the effects of two specific emotion-focused treatment elements on NSSI. Participants will be ten individuals who meet the proposed Diagnostic and Statistical Manual for Mental Disorders, 5th edition (DSM-5; American Psychiatric Association) criteria for NSSI disorder and engage in NSSI to reduce or escape from negative emotions. Two core modules of the Unified Protocol for Transdiagnostic Treatment of Emotional Disorders (UP; Barlow et al., 2011) will be adapted and delivered with the aim of reducing participants' non-suicidal self-injurious thoughts and behaviors. Each treatment module will consist of four 50-minute individual weekly sessions of emotion awareness training or cognitive reappraisal. The study will use a single-case experimental design, and phase change will be determined based on each participant's changes in non-suicidal self-injurious thoughts and behaviors.

Inclusion Criteria:

• At least 18 years old

• Engage in non-suicidal self-injury (NSSI) to reduce or lessen negative thoughts or feelings

• Not taking psychotropic medications, or meet criteria for stability on a particular dose and are willing to maintain a stable dosage throughout the study

• Meet the proposed Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5) criteria for NSSI disorder, which includes:

  1. five or more days in which the individual has engaged in NSSI in the past year
  2. NSSI is associated with at least two two of the following: psychological precipitant (e.g., negative feelings or thoughts), urge prior to the act, preoccupation with NSSI, contingent response (e.g., expectation that the act will relieve a negative feeling state)
  3. clinically significant distress or interference caused by NSSI or its consequences
  4. NSSI does not occur exclusively during states of psychosis, delirium, or intoxication
  5. absence of suicidal intent

Exclusion Criteria:

• Current suicidal ideation and intent
• Currently receiving cognitive-behavioral therapy (CBT) or any psychotherapy to address NSSI, anxiety, depression, or other Axis I disorders (and are not willing to discontinue that treatment)
• Unwilling to refrain from initiating additional treatment during the course of the study
• Current or very recent symptoms that warrant immediate clinical attention, alternative treatment, and/or a higher level of care that cannot be provided through the study (e.g., florid delusions or hallucinations, rapid mood state, severe manic symptoms)
• Current or recent (within 3 months) history of substance use disorder (exception would be marijuana, caffeine, nicotine)
• Emotional symptomatology is due to a medical/physical condition