This study predicted treatment resistance in 104 adolescents undergoing long-term residential treatment from adoptive status. Resistance was defined by rejection of adults and runaway behavior. Results indicated that these hospitalized adoptees: (1) formed significantly closer bonds with peers while rejecting close ties with adults; and (2) had significantly more runaway episodes and hospitalization terminations by runaway than nonadoptees. Termination runaways occurred after 1 year of hospitalization for adoptees. Significantly more adoptees ran away in groups of two or more patients. Psychodynamic and theoretical considerations for psychiatric treatment of adoptees are discussed and illustrated by case material, emphasizing the value of differentiating treatment approaches for patient subgroups.