While studies have shown that cognitive therapy is an effective treatment for depression, it has still not been clear the role therapists' training and expertise plays in making treatment successful.
A new study finds that depressed patients show more symptom improvement when their therapists more competently follow the guidelines for delivering cognitive therapy.
The study also suggests therapist competence may be a particularly important determinant of outcome for some patients. Researchers found that therapist competence was more strongly related to symptom improvement in patients who suffered from anxiety as well as depression, and for those who first experienced depression at an early age.
"People with depression who don't have complicating issues like anxiety are fairly likely to show benefit even if they don't see the most highly rated therapists," said Daniel Strunk, co-author of the study and assistant professor of psychology at Ohio State University.
"But people who have substantial anxiety or a history of depression that began at an early age really do best if they have the most highly rated treatment."
While the need for competent therapists might seem obvious, Strunk said there have been very few studies looking at whether the competence with which the therapy is delivered predicts subsequent outcomes. Studies that have examined the issue have tended to examine the relation of ratings of therapists and the overall outcomes of their patients. But that ignores the possibility that the competence of the therapists may not have been responsible for their patients' improvement.
"Once patients have improved, they might help to make their therapists look more competent. If so, this could explain the competence-outcome relation. So, we wanted to see if we could rule out that possibility by examining whether competence predicted subsequent outcomes," Strunk said.
The research appears in a recent issue of the Journal of Consulting and Clinical Psychology.
In this study, two researchers examined videotapes of therapy sessions involving 60 adults with moderate to severe depression and their six therapists. The researchers rated competence using the Cognitive Therapy Scale, which is also used by the accrediting organization for cognitive therapists (The Academy of Cognitive Therapy). The scale rates therapists on a variety of skills, including their interpersonal relations and their use of specific techniques thought to help patients facing depression.
The researchers rated the therapists' competence during the first four sessions with each of the 60 patients.
In addition, patients completed a questionnaire at each session that measured their depression levels.
Strunk and his colleagues then compared how competence scores given to the therapists for each session related to change in patients' depression levels from session to session.
The researchers rated competence levels without knowing how the patients were progressing and whether their symptoms were improving, Strunk said. This way, the researchers could later tell whether there was an association between competence and subsequent patient improvement.
Strunk said the strongest results came when they looked at how therapist competence was related to improvement in patients with specific characteristics. That is where they found that patients with high anxiety and early onset depression benefitted most from the highly rated therapy sessions.
In addition to looking at how therapist competence interacted with patient characteristics, the researchers also examined how competence, measured for each individual session, was related to patient improvement from one session to the next. Results showed that higher levels of therapist competence were related to more symptom improvement during the first four sessions.
The researchers also tested patients again after 16 weeks of treatment to see if competence predicted longer-term improvement. Here, competence was significantly related to patient improvement on just one of two measures of depression severity.
"When you look at how patients do after four full months of treatment, the importance of therapist competence was still there, but not as strong," he said.
Strunk said the results suggest that therapists may show higher levels of competence in some sessions compared to others, even with the same patient.
"From our results, you should expect that there will be a range of competence from session to session - even among good therapists," Strunk said.
"That may mean that the way we define competence is still not good enough, because we're finding that even highly trained therapists get below-average scores a fair number of times."
The results should encourage more study about the best way to measure competence in therapists.
"The field is still struggling to figure out how to measure competence, and that's one of the things this study is about," he said.
Strunk also said that, if replicated, these results would suggest that clinic directors should look at patient characteristics when deciding which therapists should treat individual patients with depression. Those patients with anxiety issues or early onset depression should be placed with the highest-rated therapists to get the most benefit.
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