
                         Etiology (history and causes)
                                       
Past trauma/invalidation as an antecedent

   Van der Kolk, Perry, and Herman (1991) conducted a study of patients
   who exhibited cutting behavior and suicidality. They found that
   exposure to physical or sexual abuse, physical or emotional neglect,
   and chaotic family conditions during childhood, latency and
   adolescence were reliable predictors of the amount and severity of
   cutting. The earlier the abuse began, the more likely the subjects
   were to cut and the more severe their cutting was. Sexual abuse
   victims were most likely of all to cut. They summarize,
   
     ...neglect [was] the most powerful predictor of self-destructive
     behavior. This implies that although childhood trauma contributes
     heavily to the initiation of self-destructive behavior, lack of
     secure attachments maintains it. Those ... who could not remember
     feeling special or loved by anyone as children were least able to
     ...control their self-destructive behavior.
     
   In this same paper, van der Kolk et al. note that dissociation and
   frequency of dissociative experiences appear to be related to the
   presence of self-injurious behavior. Dissociation in adulthood has
   also been positively linked to abuse, neglect, or trauma as a child.
   
   More support for the theory that physical or sexual abuse or trauma is
   an important antecedent to this behavior comes from a 1989 article in
   the American Journal of Psychiatry. Greenspan and Samuel present three
   cases in which women who seemed to have no prior psychopathology
   presented as self-cutters following a traumatic rape.
   
Invalidation independent of abuse

   Although sexual and physical abuse and neglect can seemingly
   precipitate self-injurious behavior, the converse does not hold: many
   of those who hurt themselves have suffered no childhood abuse. A 1994
   study by Zweig-Frank et al. showed no relationship at all between
   abuse, dissociation, and self-injury among patients diagnosed with
   borderline personality disorder. A followup study by Brodsky, et al.
   (1995) also showed that abuse as a child is not a marker for
   dissociation and self-injury as an adult. Because of these and other
   studies as well as personal observations, it's become obvious to me
   that there is some basic characteristic present in people who
   self-injure that is not present in those who don't, and that the
   factor is something more subtle than abuse as a child. Reading
   Linehan's work provides a good idea of what the factor is.
   
   Linehan (1993a) talks about people who SI having grown up in
   "invalidating environments." While an abusive home certainly qualifies
   as invalidating, so do other, "normal," situations. She says:
   
     An invalidating environment is one in which communication of
     private experiences is met by erratic, inappropriate, or extreme
     responses. In other words, the expression of private experiences is
     not validated; instead it is often punished and/or trivialized. the
     experience of painful emotions [is] disregarded. The individual's
     interpretations of her own behavior, including the experience of
     the intents and motivations of the behavior, are dismissed...
     
     Invalidation has two primary characteristics. First, it tells the
     individual that she is wrong in both her description and her
     analyses of her own experiences, particularly in her views of what
     is causing her own emotions, beliefs, and actions. Second, it
     attributes her experiences to socially unacceptable characteristics
     or personality traits.
     
   This invalidation can take many forms:
     * "You're angry but you just won't admit it."
     * "You say no but you mean yes, i know."
     * "You really did do (something you in truth hadn't). Stop lying."
     * "You're being hypersensitive."
     * "You're just lazy."
     * "I won't let you manipulate me like that."
     * "Cheer up. Snap out of it. You can get over this."
     * "If you'd just look on the bright side and stop being a
       pessimist..."
     * "You're just not trying hard enough."
     * "I'll give you something to cry about!"
       
   Everyone experiences invalidations like these at some time or another,
   but for people brought up in invalidating environments, these messages
   are constantly received. Parents may mean well but be too
   uncomfortable with negative emotion to allow their children to express
   it, and the result is unintentional invalidation. Chronic invalidation
   can lead to almost subconscious self-invalidation and self-distrust,
   and to the "I never mattered" feelings van der Kolk et al. describe.
   
Biological Considerations and Neurochemistry

   It has been demonstrated (Carlson, 1986) that reduced levels of
   serotonin lead to increased aggressive behavior in mice. In this
   study, serotonin inhibitors produced increased aggression and
   serotonin exciters decreased aggression in mice. Since serotonin
   levels have also been linked to depression, and depression has been
   positively identified as one of the long-term consequences of
   childhood physical abuse (Malinosky-Rummell and Hansen, 1993), this
   could explain why self-injurious behaviors are seen more frequently
   among those abused as children than among the general population
   (Malinosky-Rummel and Hansen, 1993). Apparently, the most promising
   line of investigation in this area is the hypothesis that self-harm
   may result from decreases in necessary brain neurotransmitters.
   
   This view is supported by evidence presented in Winchel and Stanley
   (1991) that although the opiate and dopaminergic systems don't seem to
   be implicated in self-harm, the serotonin system does. Drugs that are
   serotonin precursors or that block the reuptake of serotonin (thus
   making more available to the brain) seem to have some effect on
   self-harming behavior. Winchel and Staley hypothesize a relationship
   between this fact and the clinical similarities between obsessive-
   compulsive disorder (known to be helped by serotonin-enhancing drugs)
   and self-injuring behavior. They also note that some mood-stabilizing
   drugs (such as Tegretol, Depakote) can stabilize this sort of
   behavior.
   
  Serotonin
  
   Coccaro and colleagues have done much to advance the hypothesis that a
   deficit in the serotonin system is implicated in self-injurious
   behavior. They found (1997c) that irritability is the core behavioral
   correlate of serotonin function, and the exact type of aggressive
   behavior shown in response to irritation seems to be dependent on
   levels of serotonin -- if they are normal, irritability may be
   expressed by screaming, throwing things, etc. If serotonin levels are
   low, aggression increases and responses to irritation escalate into
   self-injury, suicide, and/or attacks on others.
   
   Simeon et al. (1992) found that self-injurious behavior was
   significantly negatively correlated with number of platelet imipramine
   binding sites (self-injurers have fewer platelet imipramine binding
   sites, a level of serotonin activity) and note that this "may reflect
   central serotonergic dysfunction with reduced presynaptic serotonin
   release. . . . Serotonergic dysfunction may facilitate
   self-mutilation."
   
   When these results are considered in light of work such as that by
   Stoff et al. (1987) and Birmaher et al. (1990), which links reduced
   numbers of platelet imipramine binding sites to impulsivity and
   aggression, it appears that the most appropriate classification for
   self-injurious behavior might be as an impulse-control disorder
   similar to trichotillomania, kleptomania, or compulsive gambling.
   
   Herpertz (Herpertz et al, 1995; Herpertz and Favazza, 1997) has
   investigated how blood levels of prolactin respond to doses of
   d-fenfluramine in self-injuring and control subjects. The prolactin
   response in self-injuring subjects was blunted, which is "suggestive
   of a deficit in overall and primarily pre-synaptic central 5-HT
   (serotonin) function." Stein et al. (1996) found a similar blunting of
   prolactin response on fenfluramine challenge in subjects with
   compulsive personality disorder, and Coccaro et al. (1997c) found
   prolactin response varied inversely with scores on the Life History of
   Aggression scale.
   
   It is not clear whether these abnormalities are caused by the
   trauma/abuse/invalidating experiences or whether some individuals with
   these kinds of brain abnormalities have traumatic life experiences
   that prevent their learning effective ways to cope with distress and
   that cause them to feel they have little control over what happens in
   their lives and subsequently resort to self-injury as a way of coping.
   
  Knowing when to stop -- pain doesn't seem to be a factor
  
   Most of those who self-mutilate can't quite explain it, but they know
   when to stop a session. After a certain amount of injury, the need is
   somehow satisfied and the abuser feels peaceful, calm, soothed. Only
   10% of respondents to Conterio and Favazza's 1986 survey reported
   feeling "great pain"; 23 percent reported moderate pain and 67%
   reported feeling little or no pain at all. Naloxone, a drug that
   reverses the effects of opiods (including endorphins, the body's
   natural painkillers), was given to self-mutilators in one study but
   did not prove effective (see Richardson and Zaleski, 1986). These
   findings are intriguing in light of Haines et al. (1995), a study that
   found that reduction of psychophysiological tension may be the primary
   purpose of self-injury. It may be that when a certain level of
   physiological calm is reached, the self-injurer no longer feels an
   urgent need to inflict harm on his/her body. The lack of pain may be
   due to dissociation in some self-injurers, and to the way in which
   self-injury serves as a focusing behavior for others.
   
Behavioralist explanations

   NOTE: most of this applies mainly to stereotypical self-injury, such
   as that seen in retarded and autistic clients.
   
   Much work has been done in behavioral psychology in an attempt to
   explain the etiology of self-injurious behavior. In a 1990 review,
   Belfiore and Dattilio examine three possible explanations. They quote
   Phillips and Muzaffer (1961) in describing self-injury as "measures
   carried out by an individual upon him/herself which tend to 'cut off,
   to remove, to maim, to destroy, to render imperfect' some part of the
   body." This study also found that frequency of self-injury was higher
   in females but severity tended to be more extreme in males. Belfiore
   and Dattilio also point out that the terms "self-injury" and
   "self-mutilation" are deceiving; the description given above does not
   speak to the intent of the behavior.
   
    Operant Conditioning
    
   It should be noted that explanations involving operant conditioning
   are generally more useful when dealing with stereotypic self-injury
   and less useful with episodic/repetitive behavior.
   
   Two paradigms are put forth by those who wish to explain self-injury
   in terms of operant conditioning. One is that individuals who
   self-injure are positively reinforced by getting attention and thus
   tend to repeat the self-harming acts. Another implication of this
   theory is that the sensory stimulation associated with self-harm could
   serve as a positive reinforcer and thus a stimulus for further
   self-abuse.
   
   The other posits that individuals self-injure in order to remove some
   aversive stimulus or unpleasant condition (emotional, physical,
   whatever). This negative reinforcement paradigm is supported by
   research showing that intensity of self-injury can be increased by
   increasing the "demand" of a situation. In effect, self-harm is a way
   to escape otherwise intolerable emotional pain.
   
    Sensory Contingencies
    
   One hypothesis long held has been that self-injurers are attempting to
   mediate levels of sensory arousal. Self-injury can increase sensory
   arousal (many respondents to the internet survey said it made them
   feel more real) or decrease it by masking sensory input that is even
   more distressing than the self-harm. This seems related to what Haines
   and Williams (1997) found: self-injury provides a quick and dramatic
   release of physiological tension/arousal. Cataldo and Harris (1982)
   concluded that theories of arousal, though satisfying in their
   parsimony, need to take into consideration biological bases of these
   factors.
   
   [INLINE]
   
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References

   1. file://localhost/usr/home/llama/Web/psych/diag.html
   2. file://localhost/usr/home/llama/Web/psych/injury.html
