The Problems with Habituation as an Explanation for Exposure Treatment

The Problems with Habituation as an Explanation for Exposure Treatment

NOTE: This post is part of a larger series of on the theory, practice, and research on exposure therapy. If you are interested in other posts in this series, you can find them here.

 

As discussed in a previous post, it is clear that exposure, or the systematic confrontation with feared stimuli, seems to be a critical component of most therapies, particularly for the treatment of anxiety. However, the way in which exposure is conducted and theories about it why it works vary widely. For decades, one of the dominant concepts used to guide the conduct of exposure therapy was habituation.

In the context of exposure, habituation refers to reductions in fear over time as a person encounters fear-inducing stimuli. While it was originally a term that emerged from behaviorism, it seems to more recently be used to refer to any sort of a decrease in response to a stimulus. For example, you’ve probably had the experience of putting on sunglasses and eventually forgetting that you’re wearing them until you walk indoors and notice how dark everything looks. In these instances, you’ve habituated to feel of the glasses against your skin and the darkened tint of the lenses.

As a more personal example, after getting in a car accident, I remember feeling a sense of anxiety the first few of times I drove again. However, this subsided over time and now I rarely think about the accident when I’m driving. I wasn’t in therapy and didn’t approach this in a systematic way, but I recognized my reactions as minor posttraumatic stress symptoms that would eventually recede as I habituated to driving again. This is basically the same thing that happens in exposure therapy.

In a research context, habituation is often measured through objective physiological measures such as heart rate and skin conductance or through questionnaire measures of fear, such as the Subjective Units of Distress Scale (SUDS). (Instead of “distress,” I’ve also heard “discomfort” and “disturbance” used for the “D” in SUDS.)

Within-Session and Between-Session Habituation

There are two types of habituation in exposure therapy. Within-session habituation occurs when fear decreases during a therapy session as exposure is conducted. Between-session habituation occurs when fear decreases between therapy sessions.

Habituation doesn’t mean that fear goes away completely. Many people continue to experience a fear response when they encounter certain situations. For example, professional public speakers often say that they always feel at least a little nervous before a speaking engagement. However, they generally are often less nervous than they were when they first started (which is similar to between-session habituation) or they find their nervousness goes down more quickly when they begin speaking and become involved in what they’re doing (which is similar to within-session habituation).

The Old Guideline: Within-Session Habituation is Important

It used to be that habituation was used a primary guide for exposure treatment, particularly for treatment of PTSD and obsessive-compulsive disorder. Typical guidelines would be that the person should stay in contact with the feared stimulus until his or her fear went down. At that point, exposure might be discontinued. For example, here’s a diagram of the heart rate of a person doing exposure who is afraid of cats.

Often this happens naturally. If we don’t feed our anxiety by leaving the situation, it will often decrease on it’s own within about 45 minutes. Consequently, some exposure therapies specified that a person remain in an anxiety provoking situation for 30-60 minutes, or until anxiety decreased.

The New Guideline: Within-Session Habituation Doesn’t Matter

Although habituation has supplied thousands of clinicians with a measurable marker for beginning and ending exposure treatment, research hasn’t provided a lot of support for its reliability and validity. Using habituation isn’t necessarily a bad thing—it does provide a decent marker—but researchers haven’t found much of a relationship between within-session habituation and treatment success. There’s even some question whether between-session habituation matters, but that’s a little more controversial.

I’ll be going into this issue in more depth on subsequent posts, but for now, I’ll summarize. There’s evidence that clients may show physiological decreases in anxiety but continue to report high levels of fear, and vice versa. Put simply, it may not matter much whether people experience reductions in fear through exposure. The usefulness of exposure appears to be more about people getting used to their fear than changes in how strong it is. In sum, the research evidence for habituation doesn’t support its use in exposure therapy.

Look for future posts that go into greater detail on the problems with habituation.

What is Exposure Therapy and Why Does It Matter?

What is Exposure Therapy and Why Does It Matter?

A few months ago, I received a call from a casting director looking for exposure therapists to conduct on-camera exposure for a reality TV show by the people who made Hoarders. I turned it down, of course—the ethics of it made me uncomfortable. However, the encounter suggested that exposure is becoming more widely known outside of professional circles.

Exposure has been hailed as one of the greatest success stories in cognitive behavioral treatment, and it’s currently going through a fertile period as clinicians and researchers are redefining what makes exposure work. There’s an enormous body of research on the use of exposure for things such as a panic disorder, worry, phobias, obsessive-compulsive disorder, and posttraumatic stress disorder. I intend to devote time to exploring exposure research in greater depth across future posts.

What Is Exposure?

This is a good place to start: what is exposure? In a book chapter on exposure, Moscovitch, Antony, and Swinson (2009), offer a wonderfully succinct definition: “the repeated and systematic confrontation of feared stimuli.” But what does that mean? In essence, exposure involves having someone deliberately be with an experience that he or she would normally avoid. For example, having someone afraid of heights safely stand near the edge of a building. Often we think of exposure as a component in structured cognitive behavioral treatments. However, exposure doesn’t have to be so structured. Whether they realize it are not, therapists who ask their clients to sit with painful thoughts and feelings, as they come up in session, are using exposure too.

You’ll notice that the discussion of exposure in the paragraph above focuses on the procedure of exposure. It doesn’t tell us anything about how and why exposure works. The reason for this is that decades of research have proven exposure to be an extraordinarily effective treatment, but there is no consensus on its mechanisms of change.

Research on exposure began decades ago and was rooted in the early behaviorist perspective—classical conditioning (think, Pavlov’s dogs). Exposure was a way to undo a condition association between a neutral object or experience and a fear response. Several years later, cognitive therapists began using exposure as a way to challenge or disconfirm negative thoughts about feared outcomes. There is even a variant of exposure called implosive therapy in which therapists encouraged clients to imagine scenes with psychodynamic imagery as a way to facilitate exposure.

None of these theories used to explain exposure have been entirely satisfying. In addition, adding other interventions to exposure therapy  (e.g., relaxation, psychodynamic imagery) doesn’t appear to make it any more effective. Exposure seems to work on it’s own; however, without a theory to guide it, structuring exposure sessions can be tricky.

Who Uses Exposure?

Exposure is most often used by cognitive behavioral therapists, particularly those who specialize in anxiety disorders treatment. That said, there’s a lot of therapists who think exposure is a good idea, but who don’t use it in their own practices. Barriers include lack of training, fear that clients won’t tolerate it, and general discomfort with it. Exposure can be intense—for the therapists as well as the client! For example, the blog Psychotherapy Brown Bag has a nice post on the ethics of exposure therapy.

Clinicians seem especially reluctant to use exposure for posttraumatic stress disorder. Even though exposure is a gold standard treatment for PTSD, a survey of 207 licensed psychologists found that 83% never used exposure to treat people with PTSD (Becker et al., 2004). Another survey found that 84% of women with trauma would be willing to engage in exposure treatment after the rationale was explained to them. This suggests that clients are more willing to engage in exposure than therapists.

Why Am I Writing About Exposure?

For me, this series gives me an opportunity to delve into the exposure literature. My experience with exposure is that it can be a very potent intervention, but it requires thoughtful planning to successfully implement. There’s been some fascinating new research about exposure within the past 5 years. We seem to be going through a sea change in our understanding of it. My goal through these posts is increasing understanding of how we might better use exposure as therapists in clinical practice.

UPCOMING TRAINING EVENTS


De-Mystifying Self-As-Context in ACT: Practical Strategies for Clients

Brian Pilecki, PhD and Kati Lear, PhD
December 3rd, 2021 from 12pm-1:30pm

This workshop will outline how self-as-context can be used to conceptualize commonly discussed topics in therapy such as self-esteem, confidence, identity, and inner conflict. Participants will learn how to flexibly practice practical self-as-context interventions that can be used with clients, as well as have a chance to practice newly learned skills through structured role-play exercises in breakout groups. Read More.


Values in Therapy: An Intro to Working with Values from an ACT Perspective

Jenna LeJeune, PhD
January 21, 2022 from 12pm-2:00pm

This workshop will provide a theoretical and conceptual overview of values from a contextual behavioral science perspective. We will cover the “what”, “why”, “when”, and “how” of values within ACT. While we will also provide an overview of various values exercises and measures that can be used with clients, the emphasis in this workshop will be on providing a foundational framework that will help clinicians approach values work from a functional perspective rather than a primarily technique-focused approach. Read More.



Culturally Responsive Therapy: How to Apply Anti-Racist Values in Session

Christy Tadros, LPCC and RaQuel Neal, LCSW
February 4th, 2022 from 1:30pm-4:45pm
and February 5th from 9:00am-12:00pm

This 2 day 6-hour training will help therapists develop their ability to support clients from a different racial background than them, with a particular focus on Black, Indigenous and People of Color. Through a multicultural social justice framework, it will integrate research and clinical experience to teach a therapeutic model for rapport building, assessment, and treatment. This model is not a rigid therapeutic modality, but provides a contextual lens to build a strong, culturally grounded therapeutic relationship. It is a flexible model and can align with many therapeutic modalities, including a contextual behavioral approach to therapy. Read More.


Truffle Hunting: Bringing Values to Life in the Therapy Room

Jenna LeJeune, PhD
February 25, 2022 from 12pm-2:00pm

This brief workshop is designed to help clinicians deepen their values work with clients by shifting the focus from the content of values conversations to the quality of those conversation. By listening for and deepening the qualities of effective values conversations participants will get a taste for how more experiential and relationally-based values work can supercharge therapy. Participants will have opportunities to both observe demonstrations and practice in small groups with the benefit of feedback. Read More.


Values Prototyping: Using Action to Help Clients Explore Their Values

Jenna LeJeune, PhD
March 11, 2022 from 12pm-2:00pm

This workshop will focus on one specific experiential tool called “values prototyping” that helps clients learn more about their values through engaging in intentional valuing. As participants will hopefully already have a solid foundation of some of the core concepts of the values process in ACT, this workshop will dive right in on how to use values prototyping to help clients learn more about what they would choose to value in their life. You will have the chance to practice developing a values prototype in small groups with the benefit of feedback, so that by the end of the workshop you will be able to use this tool in your work with clients. Read More.


The Invitation to Change Approach: Helping Families Affected by Addiction

Jeff Foote, PhD and Cordelia Kraus, LPC, CADC 1, certified CRAFT clinician
May 13th and 14th, 2022 from 9:00am-5:00pm
at University of Portland, Terrace Room
This two-day in-person workshop will provide skills training for professionals focused on the process of working with clients who have a loved one struggling with substance use issues. The Invitation to Change Approach draws on CRAFT (Community Reinforcement and Family Training), MI (Motivational Interviewing), and ACT (Acceptance and Commitment Therapy) to provide a compassionate and collaborative way of working with the families and concerned significant others of people who struggle with substance use. Read More.


Therapy and Research in Psychedelic Science (TRIPS) Seminar Series

Second Friday of each month from 12:00 PM – 1:00 PM (PT)

TRIPS is an online seminar series that hosts speakers discussing science-informed presentations and discussions about psychedelics to educate healthcare professionals. This series was created to guide healthcare providers and students preparing to be professionals towards the most relevant, pragmatic, and essential information about psychedelic-assisted therapy, changing legal statuses, and harm reduction approaches in order to better serve clients and communities. This seminar series is a fundraiser for our clinical trial of MDMA-assisted psychotherapy for social anxiety disorder that Portland Psychotherapy investigators are preparing for and starting in the Fall of 2021. All proceeds after presenter remuneration will go to fund this clinical trial. Read more.

January 14th, 2022Psilocybin-Assisted Therapy of Major Depressive Disorder using Acceptance and Commitment Therapy as a Therapeutic Frame with Jordan Sloshower, MD, MSc

February 11th, 2022 – Drug-Drug Interactions Between Psychiatric Medications and MDMA or Psilocybin with Aryan Sarparast, MD

May 13th, 2022Implementing Culturally-Attuned & Anti-Racist Psychedelic Therapy: Impact over Intention with Jamilah R. George, M.Div, M.S.