Stability of the patient-by-treatment interaction in the Menninger Psychotherapy Research Project

Consistent with the call to consider person-by-treatment interactions in intervention research, Blatt (1992) found that anaclitic and introjective patients responded differently to psychoanalysis and supportive-expressive therapy (SEP) in the Menninger Psychotherapy Research Project (MPRP). Psychoanalysis was significantly more effective than SEP in reducing malevolent, destructive imagery on the Rorschach among introjective patients, those patients who are primarily preoccupied with control and self-definition. Conversely, SEP was significantly more effective than psychoanalysis in reducing these malevolent, destructive images among anaclitic patients, those patients who are primarily preoccupied with interpersonal relatedness. The present analyses of data from the MPRP demonstrate the stability of this statistically significant patient-by-treatment interaction even in the subsample of patients for whom the anaclitic-introjective distinction was ambiguous, reaffirming the validity of both the anaclitic-introjective distinction and the importance of considering patient characteristics in psychotherapy research and practice.