A nationwide sample of psychologists & social workers evaluated 8 different models which address why adolescents might engage in self-mutilation: behavioural, systemic, avoidance of suicide, sexual, expression of affect, control of affect, ending depersonalization, & creating boundaries. Therapists found the expression, control, depersonalizatin, & boundaries models most useful; there was little support for the sexual or suicide models. Implications for therapy are examined. (34 refs.)