Therapist effects in the National Institute of Mental Health Treatment of Depression Collaborative Research Program

Abstract

Recent psychotherapy research literature has stressed the importance of therapist effects (i.e., the impact of the individual therapist on treatment outcome). The authors report an analysis of therapist effects in the National Institute of Mental Health Treatment of Depression Collaborative Research Program using hierarchical linear modeling. In addition to studying overall therapist effects, they investigate the possible interaction of therapists with initial patient severity and difficulty levels. There were virtually no significant findings in regard to either overall effects of therapists or the interaction with patient severity and difficulty. There was some suggestion of outliers (i.e., therapists who had especially good [or poor] rates of patient retention and recovery). Recommendations are made regarding different methodological approaches for studying outcome differences due to therapists.

In der Psychotherapieliteratur wird die Wichtigkeit von Therapeuteneffekten (d. h. der Einfluss der individuellen Therapeuten auf das Therapieergebnis) betont. Die Autoren berichten eine Analyse des Therapeuteneffektes in dem gemeinsamen Forschungsprogramm des Nationalen Instituts für psychische Gesundheit zur Behandlung von Depression unter Verwendung hierarchisch linearer Modelle. Zusätzlich zur Überprüfung von Therapeuteneffekten insgesamt, untersuchen sie die mögliche Interaktion von Therapeut mit der Schwere der Störung des Patienten zu Beginn der Therapie und verschiedenen Schwierigkeitsgraden. Es gab praktisch keine signifikanten Ergebnisse, weder in Bezug zu den Therapieeffekten insgesamt, noch zur Interaktion mit der Schwere der Störung oder dem Schwierigkeitsgrad. Man könnte jedoch in den Daten einige Ausreißer sehen (d.h. Therapeuten, die besonders gute [oder schlechte] Ergebnisse bei den Patienten erzielten). Es werden Empfehlungen gegeben hinsichtlich verschiedener methodologischer Zugangsweisen zur Untersuchung von Ergebnisunterschieden, die auf dieTherapeuten zurückzuführen sind.

La littérature sur la recherche en psychothérapie a souligné l'importance des effets du thérapeute (c'est-à-dire, l'impact du thérapeute individuel sur les résultats du traitement). Les auteurs présentent une analyse des effets du thérapeute dans le Programme de Recherche Collaboratif de l'Institut National de Santé Mentale sur la Dépression (NIMH) en utilisant un modèle hiérarchique linéaire. En plus de l’étude de l'effet global du thérapeute, ils ont examiné l'interaction possible du thérapeute avec le niveau initial de la sévérité et de la difficulté. Il n'y a pratiquement aucun résultat significatif sur le plan de l'effet global du thérapeute ou d'une interaction avec la sévérité et la difficulté. Il y a quelques indices de cas extrêmes (c'est-à-dire des thérapeutes qui ont des taux de rétention et de rétablissement de patients particulièrement bons [ou mauvais]). Des recommandations sont faites au sujet d'approches méthodologiques variées permettant l’étude des différences dans les résultats provenant des thérapeutes.

La literature sobre investigación en psicoterapia ha enfatizado la importancia de los efectos del terapeuta (v.g., el impacto del terapeuta individual en los resultados del tratamiento). Los autores informan sobre el análisis de los efectos del terapeuta en el Programa de investigación colaborativa del tratamiento de la depresión del Instituto Nacional de Salud Mental, que usa un modelo lineal jerárquico. Además de estudiar los efectos totales del terapeuta, investigan la poible interacción de los terapeutas según la gravedad inicial del paciente y sus niveles de dificultad. No hubo virtualmente hallazgos significativos con respecto a los efectos globales de los terapeutas o de la interacción con la gravedad y las dificultades del paciente. Presentan algunas sugerencias sobre las excepciones (outliers) (v.g., terapeutas que lograron marcas especialmente buenas (o pobres) de retención y recuperación de pacientes). Se dan recomendaciones respecto de diferentes enfoques metodológicos para estudiar las diferencias de resultados que provienen de los terapeutas.

La letteratura relativa alla ricerca in psicoterapia ha sottolineato l'importanza degli effetti del terapeuta (l'impatto del terapeuta individuale sull'esito del trattamento). Gli autori riportano un'analisi degli effetti del terapeuta nell'Istituto Nazionale di Trattamento della Salute Mentale nel programma di ricerca in equipe sulla depressione usando il modelling lineare gerarchico. Oltre a studiare nell'insieme gli effetti del terapeuta, viene investigata la possibile interazione dei terapeuti con i livelli di difficoltà e gravità iniziali dei pazienti. Praticamente non ci sono stati risultati significativi rispetto sia agli effetti dei terapeuti nell'insieme, sia all'interazione con la difficoltà e gravità dei pazienti. C’è stato qualche suggerimento per soggetti isolati (terapeuti che avevano specialmente buoni (o poveri) tassi di guarigione e permanenza dei pazienti). I consigli sono stati dati rispetto ad approcci metodologici diversi al fine di studiare le differenze di esito che vengono dai terapeuti.

A literatura de investigação em psicoterapia tem se preocupado com a importância dos efeitos do terapeuta (i.e., a impacto do terapeuta sobre o resultado terapêutico). Os autores descrevem uma análise dos efeitos do terapeuta no Programa Colaborativo de Investigação do Tratamento da Depressão do Instituto Nacional de Saúde Mental dos EUA usando uma análise de modelagem linear hierárquica. Além de estudar os efeitos do terapeuta em geral, investigaram uma possível interacção dos terapeutas com a severidade inicial do paciente e níveis de dificuldades. Quase não se verificaram resultados significativos no que concerne aos efeitos do terapeuta em geral ou à interacção com a severidade e dificuldades do paciente. Existem indícios de discrepâncias (i.e., terapeutas que tiveram pacientes com taxas especialmente boas de recuperação e de manutenção). São feitas recomendaç[otilde]es relativas às diferentes abordagens metodológicas para o estudo das diferenças nos resultados terapêuticos decorrentes dos terapeutas.

The National Institute of Mental Health (NIMH) Treatment of Depression Collaborative Research Program was a multisite program initiated and sponsored by the Psychosocial Treatments Research Branch, Division of Extramural Research programs (and later by the Mood, Anxiety, and Personality Disorders Research Branch, Division of Clinical Research), NIMH, Rockville, MD. The principal NIMH collaborators were Irene Elkin, coordinator; M. Tracie Shea, associate coordinator; John P. Docherty; and Morris B. Parloff. The three participating research sites and their principal investigators and project coordinators were George Washington University (Stuart M. Sotsky and David Glass); University of Pittsburgh (Stanley D. Imber and Paul A. Pilkonis); and University of Oklahoma (John T. Watkins and William Leber). The three sites responsible for training therapists and their principal investigators and project coordinators were Yale University (Myrna Weissman, Eve Chevron, and Bruce J. Rounsaville); Clarke Institute of Psychiatry (Brian F. Shaw and T. Michael Vallis); and Rush Presbyterian-St. Luke's Medical Center (Jan A. Fawcett and Phillip Epstein). Collaborators in the data management and data analysis aspects of the program were C. James Klett, Joseph F. Collins, and Roderic Gillis of the Veterans Affairs Cooperative Studies Program, Perry Point, MD.

The work presented here was supported in part by NIMH Research Scientist Award MH 01264.

We thank Robert D. Gibbons for statistical consultation and Jane Yamaguchi, Dale Faber, and Jillian Markowitz for their assistance at various stages of this study.

Notes

1. Although there are studies of therapist–patient match, the match is generally based on individual characteristics, such as race or gender or specific personality traits or values (see, e.g., studies reviewed by Beutler et al., 1994).

2. We also repeated all analyses adjusting for baseline GAS scores to control for pretreatment differences in these scores for the different therapists.

3. To the best of our knowledge and that of our statistical consultant, no one has yet worked out a way to estimate the power of random effects at the second or third level of HLM or other similar models. Given the complexity of power estimation in multilevel models, Cohen, Cohen, West, and Aiken (2003) give no guidelines for sample size, stating that “the whole issue of statistical power is complicated, because the power differs for fixed effects versus random effects as a function of effect size and intraclass correlation, and both the number of groups and number of cases per group.”