Nonsuicidal self-injury: How categorization guides treatment

The functional model is key to providing thorough clinical evaluations that should include understanding the antecedent and consequent thoughts, feelings, situations, triggers, and vulnerabilities related to NSSI acts.

The medical approach

A descriptive, phenomenological model of NSSI classification uses concepts and terminology with which most psychiatrists are familiar, takes into account patients who have comorbid psychiatric disorders, is based on atheoretical, descriptive observations, and fits into what might be regarded as a “medical model.” In this classification, NSSI usually is regarded as a symptom or associated feature of a specific psychiatric disorder, although it may occur in persons who do not meet diagnostic criteria of a mental illness—eg, “copycat” cutting in high school students.^13,14 NSSI may fall within 4 descriptive categories: major, stereotypic, compulsive, or impulsive. For psychiatric disorders associated with these types of pathological NSSI, see Table 2.

Major NSSI includes infrequent acts that destroy significant body tissue, such as eye enucleation and amputation of body parts. They are sudden, messy, and often bloody acts. Seventy-five percent occur during a psychotic state, mainly schizophrenia; of these, approximately one-half occur during a first psychotic episode.¹⁵ The reasons patients typically offer for such behavior often defy logical understanding—eg, to enhance general well-being—but most center on religion, such as a concrete interpretation of biblical texts about removing an offending eye or hand or becoming an eunuch,^16,17 or on sexuality, such as controlling troubling hypersexuality or fear of giving in to homosexual urges.¹⁸

Stereotypic NSSI acts, most commonly associated with severe and profound mental retardation, include repetitive head banging; eye gouging; biting lips, the tongue, cheeks, or fingers; and face or head slapping. The behaviors may be monotonously repetitive, have a rhythmic pattern, and be performed without shame or guilt in the presence of onlookers.

Compulsive NSSI encompasses repetitive behaviors such as severe skin scratching and nail biting, hair pulling (trichotillomania), and skin digging (delusional parasitosis).

Impulsive NSSI consists of acts such as skin cutting, burning, and carving; sticking pins or other objects under the skin or into the chest or abdomen; interfering with wound healing; and smashing hand or foot bones. These behaviors usually are episodic and occur more frequently in females. The average age of onset in patients who engage in impulsive NSSI is 12 to 14, although it may occur throughout the life cycle.

One or 2 isolated instances of impulsive NSSI do not have much prognostic importance unless they are serious enough to warrant an emergency department visit. The real danger is when the behavior becomes repetitive and “addictive.” The crossover from episodic to repetitive usually varies from 5 to 10 episodes.

Persons who engage in repetitive NSSI may use multiple methods, but skin cutting predominates. Such persons often develop a self-identity as a “cutter,” are preoccupied with their NSSI, may carve words into their skin, and may perform acts of self-harm with other self-injurers. Some may cut themselves hundreds or even thousands of times, creating scars that result in social morbidity. They often seek professional help avidly, but may become so demoralized over their inability to stop their NSSI that they are at risk for suicide.³ In some repetitive self-injurers, other impulsive behaviors such as bulimia or substance abuse may alternate or coexist with NSSI. This pattern often runs its course in 5 to 15 years and may end abruptly, especially in patients with borderline personality disorder.

Table 2

Psychiatric disorders associated with pathological NSSI