An Interview with Daniel Strunk, Ph.D., on Cognitive Therapy for Depression
David Van Nuys, Ph.D.
Dr. Strunk, a cognitive-behavioral therapy researcher, describes results of his recent psychotherapy research. Specifically, he has examined the contributions of two aspects of the psychotherapy process, rapport (or the quality of the relationship between therapist and client) and technique (or the consistency with which the therapist sticks to teaching core cognitive therapy principles within therapy sessions, and found that, given a pool of reasonably competent therapists (some masters and some journeymen), there is a direct relationship between the consistent teaching of cognitive techniques and early symptom remission, but not really a relationship between how well therapists and clients think of each other and symptom remission. Dr. Strunk is quick to point out that rapport would likely have become more important if therapists taking part in the research had been seriously lacking in rapport building skills. He emphasizes that both cognitive therapy for depression and medication therapy for depression have been shown to be effective treatments for depression, and that since the majority of depressed people go untreated, the most important thing is that people who are suffering get themselves into an effective treatment of some kind.
David Van Nuys: Welcome to Wise Counsel, a podcast interview series sponsored by CenterSite, LLC, covering topics in mental health, wellness, and psychotherapy. My name is Dr. David Van Nuys. I'm a clinical psychologist and your host.
On today's show, we'll be talking with Dr. Daniel Strunk about cognitive interventions for severe depression. Daniel R. Strunk, Ph.D., is an assistant professor in the Department of Psychology at the Ohio State University. In 1999 Dan completed his undergraduate work at Northern Kentucky University. In 2004 he earned his Ph.D. in clinical psychology at the University of Pennsylvania. He completed a post doctoral fellowship at Vanderbilt University and has been at Ohio State since 2006.
Much of Dan's research to date has examined the nature of cognitive biases in major depressive disorder or the process of change in cognitive therapy for depression. In his work on cognitive biases, Dan has shown negative biases are typical of those with high levels of depressive symptoms and major depressive disorder. In his work on the process of change in cognitive therapy for depression, Dan has examined different therapist strategies used in cognitive therapy as predictors ob relatively immediate symptom change. He also examined the role of skills patients develop in cognitive therapy in predicting lower risk of relapse following treatment. Now, here's the interview.
Daniel Strunk, welcome to Wise Counsel.
Daniel Strunk: Thanks for having me. I'm delighted with your interest.
David: Well, let's start out with a bit about your background. Tell us a bit about how you got into psychology and all of that good stuff.
Daniel Strunk: Sure. I'm someone who appreciates things that are practical and one of the things that appeals to me about the topic I study and clinical psychology more broadly is the idea that we can improve mental health for people through kind of practical, empirical tests. And so that's part of what has gotten me excited about my work.
I've worked with Rob DeRubeis and Steve Hollon at the University of Pennsylvania and Vanderbilt University. They've been great collaborators and great mentors. They've done a lot of work on studying cognitive therapy for depression, which is something I've continued, and I think it's a treatment with a lot of promise, and yet there's a lot of basic questions that we don't know the answers to yet, and so that's what we've been spending our time doing, trying to figure out how is it that this treatment works to the extent that it does, and what could we do to make it even better still.
David: Well, I'm not familiar with either of those names, but I did go to the University of Pennsylvania as an undergraduate a long time ago.
Daniel Strunk: Okay.
David: And I know that in the interim, they've become a real powerhouse in terms of cognitive approaches to psychotherapy.
Daniel Strunk: Certainly. Yeah, Aaron Beck is there, one of the important founders of the approach, and there are a number of psychotherapy researchers there who are well known and doing important work.
David: Yes, I interviewed Aaron's daughter, actually, Judy Beck, in this same series here, so -
David: Yeah. Well, you recently published a research paper on cognitive therapy for severe depression, and so, first of all, we hear a lot these days about cognitive behavior therapy or CBT. What's the difference between cognitive behavior therapy and cognitive therapy?
Daniel Strunk: Sure, it's an important question. I think that the difference is not really there. They're synonyms. The term cognitive therapy was really - came into prominence when Beck used it, and he used it to emphasize the importance of cognitive approaches, but a cognitive therapy has always emphasized behavioral approaches as well. And so a cognitive therapy is an approach that uses both cognitive and behavioral interventions, but the name obviously emphasizes the cognitive features more strongly.
David: Okay, well, that's good background to have. Now, according to your recent behavior therapy and theory journal article, a number of studies have shown cognitive therapy for severe depression to be an effective and maybe even longer lasting compared to pharmacological treatment. So tell us a bit about that.
Daniel Strunk: Sure. I think it's important to put this research in context a little bit, so this is additional analysis of a study that was really conducted to address the question of how does cognitive therapy compare to medications for moderate to severe depression, which has actually been a point of some controversy. The point of our paper was to ask the question, "Given the efficacy of cognitive therapy among the more moderately severely depressed patients, what is it that's responsible for that symptom change?" Because, like many psychotherapies, there's a lot of flexibility built into the treatment manual, so that competent cognitive therapists might very well make different decisions about what kinds of interventions to emphasize with different patients and, you know, presumably they all have ideas about how they're doing that, but it's not at all uniform, and there are pretty different ideas about what might be responsible for that symptom change.
So in our paper, what we did was we looked at the first several sessions, the first four sessions, of the cognitive therapy cases in this set of 60 patients who participated in the cognitive therapy condition of this trial. And we had observers code the sessions for various behaviors that the therapists might engage in, things that they might choose to do: using a behavioral approach, using a more cognitive approach, for example. And we also had them characterize the nature of the relationship between the therapist and the patient, which has been a variable that's gotten an awful lot of attention in psychotherapy research.
And our primary analyses looked at the question of what kinds of characterizations of these sessions - so what kinds of therapist behaviors, what kinds of descriptions of the way that the therapist, patient, are relating to one another - best predict kind of session to session symptom improvement early on in the course of cognitive therapy.
David: There are a couple of things that you touched on that I'd like to go back to.
Daniel Strunk: Sure.
David: One was you said that there's been a lot of controversy. Can you tell us what that controversy is?
Daniel Strunk: Absolutely, sure. Part of the controversy goes back to kind of a seminal clinical trial - the Treatment for Depression and Collaborative Research Program study - which suggested that, among other things, it seemed to be taken to suggest that cognitive therapy might not be as effective for more severe forms of depression, and some people have taken those data to suggest that medication might be really the appropriate treatment for more severe forms of depression.
David: Yeah, I think that's what I had heard.
Daniel Strunk: But other people have gone and looked - I mean Rob DeRubeis in particular has gone and looked at date from a number of different studies, and the picture isn't that clear across the other studies. In fact, on average across studies, it appears that both cognitive therapy and pharmacological treatment perform similarly in the treatment of moderate to severe depression.
And in a recent study, the largest study of its kind, published a few years ago by DeRubeis and Hollon, they found that cognitive therapy did as well as antidepressant medication, specifically with the moderately severely depressed folks. So I think that the overall combination of data and the single largest study conducted to address this question to date now suggests that cognitive therapy is as effective as the current first line treatment as it is usually used or utilized, aggressive mediation treatment.
David: Well, that's fascinating. Now, the other thing that you said in passing was you made reference to manualized treatment, and you said that everyone may not implement the manual instructions in the same way. And I was interested in that because I've sort of been on the sidelines watching this move towards manualized treatment and had the impression that the attempt is to make it so that everybody kind of does the same thing, which I'm a bit skeptical about, frankly.
Daniel Strunk: Right.
David: So I was interested when you said, well, you know there are these variations. Say a little bit about that if you will.
Daniel Strunk: Sure. It's really - it's a pretty important issue because for better or for worse - and certainly there are views on both sides of this - manuals are the primary way that treatment outcome researchers communicate with clinicians about the treatments they're studying. So what are the procedures they're using in a given clinician trial? And manuals can take a lot of different forms, so certainly a manual can specify quite clearly and with a great degree of specificity what a therapist should do. But they don't always, and some treatment developers presumably think that over-specification might be a problem and that it might be better to have a kind of principle-driven treatment.
I think it's fair to say that cognitive therapy for depression is a fairly principle-driven treatment, meaning that the therapists are working from core principles in working with the patients with depression. But it doesn't tell them exactly what to do in session one or session two, or there's quite a bit of flexibility in determining how to implement that treatment. And that could be a good thing; it could be that that kind of flexibility helps therapists tailor the treatments to get maximally good clinical outcomes, but it also creates a problem because, to the extent that there's flexibility that's not clearly defined, the question is, as a clinician, if I want to implement this treatment, how do I know what they were studying in these trials and what parts of that were important to getting good outcomes?
David: Okay, yes. Well, it certainly is a complex issue. Now, as I understand it, you set out to measure the impact of two things: therapists' adherence and the therapeutic alliance. So tell us what each of these means, if you will.
Daniel Strunk: Absolutely, sure. A therapist's adherence refers to adherence to the treatment manual, so when a therapist is adherent, that therapist is engaging in the behaviors that are prescribed in the treatment manual.
David: Following the instructions, basically.
Daniel Strunk: Following the instructions. Now, that doesn't mean they're following the instructions in a cookie cutter fashion or thoughtlessly, but it means they're adhering to the core principles of the treatment.
Daniel Strunk: So in cognitive therapy that means that they're encouraging patients to be skeptical about the validity of their automatic thoughts. So a patient comes in; they're asked to work to identify these automatic thoughts that pop into their mind when they're feeling badly and to be skeptical of those things and subject them to careful scrutiny. So those kinds of things the therapist would be encouraging patients to do would be an example of adherent behaviors.
And it can be a lot of different things, so I just gave an example that would be a more cognitive element, but there would also be things that would be more behavioral: so encouraging patients to structure their day carefully, or to schedule some kind of small behavioral changes in order to develop a sense of mastery and accomplishment even in the midst of a depressive episode.
So that's sort of the therapist adherence end of it. The alliance end of it is really describing the quality of the relationship. And there are a couple of ways of thinking about this, but one aspect of that is sort of the affective bond between the two people. So do they like one another? Do they have a good working relationship? And then there's also elements having to do with whether they agree on the activity they're engaged in. Are they both working on something that they seem to be thinking of as a constructive endeavor?
Some people have suggested it really doesn't matter what you do with patients; it just matters if you have a good working relationship. And others have suggested that maybe there are some things that are better than others to do in addition to the work.
David: Maybe this is the thing that you were just speaking about: you develop a measure to assess patients' facilitation or inhibition of therapist offered cognitive therapist techniques. What does that mean - facilitation or inhibition of the therapist?
Daniel Strunk: Yeah, this is sort of - you might think of this as in between adherence and alliance. So this is something that describes how the clients are behaving in the sessions, and the idea is that some people really take to the suggestions of cognitive therapy. The model resonates with them; they get it. Other people it's a real struggle to see how it fits with their experience and fits with their life. And some patients might be really trying to make a very good effort. They might naturally have a better fit of the model with them. And others might be more reluctant to do so.
So that client facilitation has to do with the extent to which they're making an active effort to apply the principles of treatments on their own, both in the session and between sessions.
David: It sounds like it might tap into some of what, in the past, might have been called resistance.
Daniel Strunk: Yes, it would be hard to distinguish them clearly. I think they're closely related ideas.
David: Okay. So, you also wanted to study these effects early in the therapy process, so you focused on the first four sessions. What was the reason for that decision?
Daniel Strunk: Yeah, there are a few things that occurred to us. One of the most important is that the biggest changes in terms of symptom improvement tend to happen early in treatment, so if you want to understand what's helping patients to get better, you want to look at when the change is happening.
In addition, we have hypotheses about the time over which these interventions would take effect, and we think that the changes, when they take place, would likely happen pretty rapidly. So if someone develops a new perspective on their life, it's probably not the kind of thing that has to sit with them for six weeks. When it really takes, at least our clinical experience would suggest that they see marked improvement at that time. So we thought that we could look at short term changes when a lot of change is happening early on in treatment. That was kind of the basic rationale.
Of course, there could be other things happening later in treatment that are interesting. We just kind of made this the priority for this initial look at what's driving change.
David: And you also chose to study these effects over a number of therapy sessions rather than just at the end of therapy. What was the reason behind that choice?
Daniel Strunk: Yeah, that's a good question. I think it's hard to get a large data set of therapists providing really good cognitive therapy for depression where you have as much information about the patients as we did in the context of this clinical trial. And so one thing we wanted to do is wanted to really maximize our power, our ability to detect any effects. And by getting these kind of repeated measures of what the therapists are doing across multiple sessions, we thought we'd be better able to detect whatever effects might exist.
David: Okay. Well, describe for us, if you will, the experimental set up for the study in your article. For example, how many patients were chosen; how were they chosen; how were the therapists chosen; how many and any other details that you think we might want to know.
Daniel Strunk: Sure. So these were 60 patients who were randomly assigned to the cognitive therapy arm of a clinical trial. They were moderately to severely depressed, so in a typical study, this would represent the more depressed half of the sample. So these were people who had higher levels of depressive symptoms than would be true of a general depression outcome study.
They are a group of patients who have a number of other problems, because we think that that is actually pretty typical. Depression is related to problems like anxiety, and it's sort of non-representative to study people who have stand-alone problems when that's not the norm. So we think that this is a sample of patients with moderate to severe depression who have a fair degree of co-morbidity, which we think would be typical.
The therapists were six therapists who were all trained in cognitive therapy for depression. Some of them were extremely highly experts, and some of them were more moderately expert in terms of using cognitive therapy specifically.
David: How was the level of patient depression assessed? Was that assessed by therapists or by taking an inventory or a combination?
Daniel Strunk: Yeah, so the kind of gold standard in the field is to assess things in multiple ways, and one way is through a semi-structured interview, to have a kind of clearly standardized procedure for assessing depressive symptoms conducted by an independent evaluator, not the therapist. And the other method is to get patients to report through a self-report measure.
In our paper, we really focused on those self-report measures because they can be given quite frequently, so that way we can get repeated assessments and we can look at change over a period of a few days, from one session to the next. Early on in treatment, people were being seen twice a week, so they'd be coming in and filling out the Beck Depression Inventory on each occasion. And so we can look at how those scores change over fairly small windows.
David: And then in terms of analysis, you had raters scoring the various process variables - for example, the therapeutic alliance and so on. Were they using videotapes or audiotapes? Or, you know, what materials were they using for their ratings?
Daniel Strunk: Yes. It's overwhelmingly videotape, so audiotapes were only used on occasion when there was a technical problem with a given video. And we think that's important partly because when you're characterizing something like the alliance, you want to be attending not only to the words that are spoken, but the tone of voice and body language and sort of the overall message being conveyed.
David: So let's talk about the results now. What were your findings in relation to, say, therapist adherence to the model and improvement from depression?
Daniel Strunk: Sure. Well, we had one predictor that was particularly robust, and that was therapist use of cognitive methods. So this refers to the therapist efforts to encourage skepticism about the patient's kind of negative thoughts related to their emotional reactions. The more therapists were emphasizing these cognitive methods and asking questions to help patients think through different possible explanations that might be competing explanations for those negative thoughts they're having, the more patients appeared to get better from one session to the next across those first several sessions. That was by far our strongest predictor.
We also got a predictor that reflects kind of therapist working, collaborating, making efficient use of the therapy sessions. So the more that therapists were engaging in that kind of negotiating topics collaboratively and making good, efficient use of their time, the more patients experienced session to session symptom improvement.
What was not a significant predictor, and somewhat surprising to us, was the behavioral methods. So this would include things like patients being encouraged to track what they're doing, what their moods are like, to try out some activities that might give them a sense of pleasure. And that was pretty surprising to us. I think that that's one of the things that I think calls for the most critical thinking in terms of thinking about what that means. And I'm glad to come back to that if you'd like.
Daniel Strunk: The other finding we had was that the therapeutic alliance was not a significant predictor, and the effect size was pretty small, and I think that also calls for some thought about how to interpret that. Certainly wouldn't want people to think that that means being a callous, uncaring therapist is just fine. I think you have to think about this as six fairly expert therapists doing their best to work well with patients, and in that context what appears to be helpful is the variability in things like cognitive methods, and the variability in terms of the therapeutic relationship was much less important in terms of predicting how patients did.
David: Are you saying that it was because there was sort of a floor effect, that all of the therapists were sufficiently skilled in building an alliance that there wasn't enough variability to generate that kind of significant difference?
Daniel Strunk: It's hard to know. It was certainly our experience with the raters that there was substantial variability in the alliance. Nonetheless, I think that there may have been a restriction of range, and if you were to think about the wider field of psychologists providing psychotherapy, it could be that there's a much wider range of alliance, and that in that greater range should be - you know, differences would have more consequence.
David: Yeah, because that's the finding that really surprised me. It seems to me to fly in the face of a lot of past research and therapeutic experience - not that I could cite the research, but I have that impression.
Daniel Strunk: Well, let me say a couple things about that. People have spent a lot of time, a lot of energy, studying the relationship between the therapeutic alliance and outcome, and therapists very often believe that it's a very important ingredient of successful treatments. In fact, many analytic studies suggest that it's related to outcome, but its relationship is modest. And, in fact, even that modest relationship might be to some degree a methodological artifact.
Let me give you a little bit of a sense of how that would work. So when we did our study, we looked at these characterizations of the therapy sessions as predictors of subsequent symptom change - so how patients change from a given session to the next session. But in a good deal of the psychotherapy process research, that has not been done, and so some of those studies estimating the alliance outcome relationship could be partly due to patients who do better forming better alliances with their therapist, rather than the positive therapeutic alliance leading to better outcomes.
In fact, we did an analysis to address just that issue. So one way of looking at our data would be to say did the alliance predict subsequent symptom change, and we failed to find that relation. The other way is to look and say, "Do patients who improve, do they tend to have better alliances in the following session?" And we found strong evidence for that. So the alliance scores, at least in our sample of cognitive therapy patients, seemed to be a function of prior symptom change, and we were unable to say that they predict subsequent symptom change.
David: Hmm. And what were the results in relation to patient facilitation or inhibition of the therapist's cognitive interventions? I know that was one of the things you were interested in.
Daniel Strunk: Yes, that was a significant predictor. It was not as strong a predictor as the cognitive methods, but it was a clear and significant predictor. So I think we could say that it's both important for therapists to engage in the particular behaviors highlighted by our study and that patients who are actively engaged in that effort are more likely to see good session to session benefit.
David: So pulling back from the details of your study, what would you say the big picture looks like?
Daniel Strunk: Yeah, I think that one of the exciting things that I think the big picture suggests is that these cognitive approaches appear to be useful even for more severely depressed patients right at the very outset of treatment. And you know there's a couple of reasons people might be surprised by that.
In recent years there's been quite a bit of excitement about behavioral treatments for depression, and because of that, some people might have been kind of suspecting that to the extent that a cognitive therapy works - especially early on, especially with more severely depressed patients - it might be driven by these behavioral approaches. But our data appeared to suggest the opposite; that actually the cognitive approaches are quite important with those patients. So that's one important implication, I think, of the findings.
The other, with the alliance, is something more tricky. I certainly wouldn't want people to take the wrong message and think, oh, the relationship doesn't matter in some kind of absolute sense, but in terms of people who are therapists who are trying to deliver a good treatment, it appears that the kind of variability you see among fairly expert, competent therapists doesn't account for a lot of the variance. And so it might be that there are other variables that would be better explanatory factors.
And so certainly wouldn't want to that if patients or therapists took a totally different approach, where they were kind of cold hearted or something, that that would not lead to bad outcomes. But the kind of variability we typically saw didn't account for change, and so it might not be that we should spend all our time focused on fostering that element of the therapist relationship. We might want to be sure to cover some of these things that do predict subsequent symptom change as well.
David: Well, do you think that that negative finding in relation to the alliance would need to be replicated before putting a lot of faith in it?
Daniel Strunk: Yeah. I want to say this is the third study to find this relationship, so - to fail to find this relationship, I should say. So Rob DeRubeis has twice before found very small relationships between the alliance and subsequent symptom change, and recently Jacques Barber provided a summary of the alliance literature, where he emphasized or went through and looked at the number of studies that have looked at the alliance as a predictor of subsequent symptom change. The average relationship there - some of them were significant - but the average relationship was quite small. So it actually - I mean we'd be talking about well under 5% of the variance in outcome that would be accounted for by the alliance.
David: Now, are you also trained as a clinician?
Daniel Strunk: I am, yes.
David: So you're both a clinician and a researcher.
Daniel Strunk: Yes.
David: Well, that's a great combination because certainly we do need more research. And what sort of follow-up research is needed? Where do you think we need to go from here?
Daniel Strunk: I think there are a lot of interesting possibilities. One of the possibilities that we've been intrigued by recently is the idea that there might be different strategies better suited to different patients, and being able to anticipate what that way of matching intervention strategy to patient from the outset would really allow us to improve our treatment efforts in a pretty dramatic way. People have certainly had that idea in the past, but we've struggled to find the relevant matching variables. But that's something that we're pursuing currently - trying to figure out with what kind of patients would which of these approaches be most helpful.
David: Yes, that definitely makes sense as a direction to go. You know I just happened to see the Charlie Rose series on the brain and the episode that they did on psychopathology. Did you see that one?
Daniel Strunk: I don't think I did.
David: Boy, it's very impressive, and I wish I could remember the names of the guests that they had on that show. One of the things that attracted me to wanting to interview you was seeing a reference to this research that you had done, and I'd been under the impression that severe depression was reasonably intractable or challenging, and so I thought your findings are very interesting.
Daniel Strunk: You know, we haven't talked about this study, but there's another study we did a couple years ago that speaks to what you were just mentioning there. One of the most exciting things - I think perhaps the most exciting thing - about cognitive therapy for depression is the idea that it teaches patients something they can use after treatment ends. And perhaps relatedly, patients who discontinue cognitive therapy appear to be at reduced risk for relapse. And we have some findings suggesting that, to the extent that patients master the skills that they are working with their cognitive therapist to develop, and they're using those skills, they're much more likely to stay well after treatment ends.
Now, granted, that's all mediated by the brain. Presumably that's where these variables exist. But it's that kind of deliberate, effortful skill use that we think is helping patients stay well after treatment has terminated.
David: Yeah, one of the fascinating conclusions of these brain experts who appeared on this Charlie Rose show was they were all in agreement that psychotherapy is important, and that psychotherapy in conjunction with pharmacologic approaches is also very important in dealing with major disorders. So it was interesting to hear that even though they're research careers were staked out more in the biological, neurological realm, they were still coming down strongly on the efficacy of psychotherapy.
Daniel Strunk: Yeah, and I certainly think that there are some really smart people working to understand the biological mechanisms by which these therapies exert their effects. I know there's been some exciting work in that regard, and that may be have been one of the topics for the show.
David: Yes, it was. Well, as we wind down, is there anything else that you'd like to say?
Daniel Strunk: Well, I'm not sure what would be of most interest to people. One thing that I guess I would encourage people to do is if I'm talking to people or people who are listening to this interview are people who are perhaps struggling with depression, the most important message we get from this kind of research is that treatment helps, and that a large number of people don't pursue treatment, and so people are kind of on the fence about whether that would be useful for them. There's lots of data to suggest that there are good treatments that would be very helpful for folks, and that taking that kind of first, courageous step to pursue treatment is likely to be well rewarded.
David: Oh, that's an important message to leave people with. Is there perhaps a website at the University of Pennsylvania that would help people locate resources?
Daniel Strunk: I'm at Ohio State.
David: Oh, I'm sorry. I forgot that. Yes, for a while you were at Pennsylvania.
Daniel Strunk: Yes. Right I was. Yeah.
David: I don't care where the database is.
Daniel Strunk: Sure, I understand.
David: If you have a resource, that would be good.
Daniel Strunk: We have a website that is for our depression treatment and research clinic, and it has links to things like information provided by the National Institute of Mental Health. That'd be one kind of website. I won't read the whole URL over the web, but if you search for depression treatment and research clinic, Ohio State, it would come up in a Google search, for example.
David: Okay. Excellent. Well, Daniel Strunk, thanks so much for being my guest on Wise Counsel.
Daniel Strunk: Thanks for having me. Thanks for your interest.
David: I hope you enjoyed this interview with clinician and researcher Daniel Strunk. If you're interested in the research we were discussing, and have access to an academic library or access to an online reference service, his article appeared in the journal Behaviour Research and Therapy, number 48, 2010, pages 599 through 606. And Behavior has the British spelling of B-E-H-A-V-I-O-U-R. Also you can find Dan's academic website with a list of his publications by googling him. Just google Daniel Strunk, Ohio State, and you'll find his website easily.
You've been listening to Wise Counsel, a podcast interview series sponsored by CenterSite, LLC.
If you like Wise Counsel, you might also like ShrinkRapRadio, my other interview podcast series, which is available online at www.shrinkrapradio.com. Until next time, this is Dr. David Van Nuys, and you've been listening to Wise Counsel.
Daniel R. Strunk, Ph.D. is an Assistant Professor in the Department of Psychology at The Ohio State University. In 1999, Dan completed his undergraduate work at Northern Kentucky University. In 2004, he earned his Ph.D. in clinical psychology studying with Rob DeRubeis at the University of Pennsylvania. He completed a postdoctoral fellowship at Vanderbilt University with Steve Hollon and has been at Ohio State since 2006.
Much of Dan's research to date has examined the nature of cognitive biases in Major Depressive Disorder or the process of change in cognitive therapy for depression. In his work on cognitive biases, Dan has shown negative biases are typical of those with high levels of depressive symptoms and major depressive disorder. In his work on the process of change in cognitive therapy for depression, Dan has examined different therapist strategies used in cognitive therapy as predictors of relatively immediate symptom change. He also examined the role of skills patients develop in cognitive therapy in predicting lower risk of relapse following treatment.