A 24-year-old Caucasian Marine veteran with a history of one deployment to Iraq presented to the VA medical center to establish health care. On intake to primary care, he screened positive for PTSD and was referred for specialty services to the posttraumatic stress clinical team. The patient reported that his primary combat duties included going from house to house and clearing rooms one at a time to secure neighborhoods. In the context of that duty he reported being exposed to multiple life-threatening situations and firefights, witnessing dead and mutilated bodies, making many split-second life-or-death decisions, and losing two of his friends to combat-related death. After returning to the United States he began to experience at least eight distinct intrusive memories and nightmares from these combat experiences. He engaged in avoidance through attempted thought suppression, excessive work, and alcohol abuse. He avoided crowds and social situations and dropped out of college because he felt unable to focus on his academic duties as a result of his symptoms. On presentation to the posttraumatic stress clinical team, he was diagnosed with PTSD according to the SCID, and he scored in the clinical range on the PTSD Checklist (a score of 69 out of a possible 85) and the BDI (a score of 30 out of a possible 63). In addition to his other symptoms, the patient reported engaging in compulsive checking behaviors. He reported checking his front door lock 10 to 30 times a day and peeking out of his window blinds 30 to 50 times per day. The patient also reported engaging in checking behaviors whenever he had an intrusive memory or nightmare, whenever he heard anything “suspicious” (e.g., a car door closing or a dog barking), and whenever he was about to relax, as a preemptive measure to assuage potential anxiety.

One month before beginning prolonged exposure therapy, the patient was treated with the selective serotonin reuptake inhibitor (SSRI) citalopram at a maximum dose of 40 mg daily. Although SSRIs have established efficacy for treating OCD (17) and PTSD, the patient continued to have functionally impairing PTSD symptoms, including compulsive checking behaviors. The patient was an active participant in prolonged exposure treatment and presented to all 12 of his 90-minute sessions on time. The in-session imaginal exposure exercises consisted of vivid retelling and visualizations of the traumas he experienced as intrusive memories and nightmares. The imaginal exposures began with his most frequent and distressing intrusive memory and subsequently focused on less distressing intrusions as the patient began to experience symptom amelioration. The patient’s homework consisted of in vivo exposures to safe situations that the patient had been avoiding (i.e., going to the post office to mail his bills or to the food court at the mall during a weekday). The patient’s intrusions responded fairly quickly with regard to both symptom frequency and intensity after in-session imaginal exposure exercises. After five sessions, the patient scored a 40 on the PTSD Checklist and a 22 on the BDI, and he expressed having some relief from his intrusions. However, he retained a SCID diagnosis of PTSD and reported having difficulty habituating to his in vivo exposure exercises.

During this period of treatment, the patient’s compulsive door and window checking were reduced as a result of the amelioration of intrusions, which were often the impetus for his checking in the first place. However, the actual behavioral reinforcement of checking whenever he did feel anxious continued and remained clinically significant. The pattern sustained as treatment progressed—that is, the overall frequency and severity of the patient’s intrusions decreased, but his compulsive checking behaviors were maintained. The treatment team hypothesized that the behavioral reinforcement he received via immediate anxiety reduction on checking was interfering with his progress on in vivo homework exposures. That is, the patient’s self-reinforcing checking behaviors in response to anxiety at home made it more difficult for him to tolerate any anxiety long enough to experience success outside the home in regaining prepathological social functioning. Attempts to assign him in vivo homework not to check were unsuccessful. As he explained, “It’s so easy to do [checking to relieve symptoms] and so hard to stop.” Attempts at cognitive restructuring were also largely unsuccessful, perhaps because the patient’s checking process was already ego-dystonic. As the patient explained, “Sitting here [in the clinic], I know that a bunch of Iraqi insurgents are not going to bust in my door, but at home when I’m amped up, I can’t help myself, I’m up and I’m checking.”

The eighth treatment meeting consisted of an in-home exposure session where response prevention was added to the in vivo exposure paradigm. The patient and therapist sat in the patient’s living room and waited for naturally occurring sounds—car doors closing, dogs barking, trucks going over potholes, and the like—from the outside to induce anxiety. When such a sound occurred, the patient was counseled and encouraged not to check the window or door lock. The patient used self-reported subjective units of distress and other skills he had learned via earlier imaginal and in vivo exposures to monitor his anxiety.

Anxiety-inducing sounds occurred about every 4 minutes on average. The patient was able to refrain from checking behaviors and also was able to habituate to normal neighborhood sounds within the session. The treatment team hypothesized that the patient was able to experience such success because of the increased support and accountability resulting from the therapist being present in the ecological context of his symptoms. Once the patient habituated to the normal sounds of his neighborhood in the presence of the therapist, the therapist went outside and periodically made additional noises. The patient knew the therapist was going to do this and was instructed not to check the window. Although the patient knew the therapist was making the noise, he reported having a more difficult time not checking because the noise was “a little louder and closer.” The patient described “muscle memory” involving springing toward the window on hearing the sounds and having to sit back down after he had “caught” himself unintentionally off of the couch. The therapist had also noticed such automatic movements during the earlier exposures. These movements may explain why cognitive restructuring, emotional processing of the patient’s traumas, and assigned in vivo homework had not led to extinction of the checking behaviors; the patient’s checking behaviors were ingrained enough to be “overlearned” and appeared to be operating, at least in part, independently of executive functioning. However, focused and repeated practice of in vivo exposure and response prevention led to within-session extinction of the urge to check. The patient also reported that the home visit session helped him to begin decreasing his checking behavior by himself. The remaining four sessions focused on consolidating treatment gains concerning the patient’s intrusions, strengthening his ability to refrain from checking behaviors, and expanding his tolerance for participating in social and functional activities that involved crowds.

Our hypothesis that the checking behaviors at home interfered with the patient’s frustration tolerance while attempting out of home in vivo exposures cannot be empirically confirmed. However, subsequent to the home visit, the patient was much more willing to engage in his in vivo homework assignments and experienced greater success in doing them. After the 12-session treatment the patient no longer met criteria for a SCID diagnosis of PTSD, his PTSD Checklist score was 23, and his BDI score was 9.

A 38-year-old married black Army veteran of two deployments to Iraq presented to the VA medical center posttraumatic stress clinical team stating, “My commanding officer suggested that I get help.” The patient’s primary duties during both of his tours included providing security for truck convoys by patrolling alongside them in an armed Humvee. In the course of these duties he was exposed to multiple life-threatening situations, witnessed an improvised explosive device detonate during a convoy, witnessed dead and mutilated bodies, witnessed a motor vehicle run over a little girl, and was responsible for checking the convoy trucks and accompanying vehicles for bombs. At the time of intake he was experiencing more than 10 distinct intrusive memories. He engaged in avoidance through attempted thought suppression, doing his errands late at night to avoid people, and staying home as much as possible while not at work. On presentation to the posttraumatic stress clinical team, he was diagnosed with PTSD according to SCID criteria and scored in the clinical range on the PTSD Checklist (a score of 68) and the BDI (a score of 31). The patient also engaged in compulsive checking behaviors. He checked under his car and under the hood of his car for bombs every time he needed to drive (two to eight times per day). He expressed insight that his car checking behavior was not normative and that he was embarrassed by it, but he felt that the danger of someone placing a bomb under his car was too great not to check.

The patient was treated with citalopram, at a maximum dose of 40 mg, for 7 weeks before beginning prolonged exposure therapy but continued to have a significant PTSD symptom burden, including compulsive behaviors. The patient was an active participant in prolonged exposure therapy and arrived on time to 15 sessions. Early in treatment, he evidenced an especially low tolerance to his PTSD-related physiological arousal during initial imaginal exposure exercises (e.g., speeding heart, shortness of breath, and tingling in his hands). Accordingly, treatment incorporated interoceptive exposure (18) exercises to help desensitize the patient to these specific physiological symptoms. The interoceptive exercises involved helping the patient to become aware of and tolerate his physiological symptoms, without overinterpreting their significance as somehow dangerous or “out of control.” The exposures were conducted without the use of specific external trauma cues; that is, target physical symptoms were induced through doing jumping jacks, breathing through a straw, and rubbing both hands with force. Thus, the patient learned to sit with and tolerate the simulated feeling of his activated sympathetic nervous system. The interoceptive exercises were completed by both the patient and the clinician, improving rapport, encouraging levity in the treatment process, and instilling a sense of teamwork. Additionally, as suggested by earlier work investigating augmentation of PTSD-oriented exposure therapy with other cognitive-behavioral techniques (19), the interoceptive exposures were done in addition to imaginal and in vivo exposures. That is, overall treatment time was expanded to accommodate the added component of the interoceptive exposures without encroaching on time devoted to imaginal and in vivo exposures. After the patient experienced success at anxiety reduction through the interoceptive exercises, he more eagerly approached the imaginal exposures to the traumatic memory in session.

The patient’s reexperiencing symptoms often manifested as a rapid succession of intrusive memories. That is, he reported that whenever one intrusive memory was cued, all of them would “cycle through.” Because the intrusive memories seemed related and were experienced with high levels of distress at the same time, it would often take the patient 2 or 3 weeks to realize that he had not experienced a distinct intrusive memory subsequent to exposure and processing. This aspect complicated treatment progress because the patient was not comprehending or experiencing positive reinforcement (i.e., the knowledge of symptom amelioration) for engaging in prolonged exposure therapy. Nonetheless, the patient and therapist maintained good rapport, and the patient began to realize significant decreases in intrusive memories by the ninth session (PTSD Checklist score=45, BDI score=19). At the same time, however, the patient was making little progress in limiting his car checking behaviors or in successfully habituating to, or completing, in vivo exposure activities.

The 10th treatment session consisted of in-home in vivo exposure and response prevention exercises. The patient and therapist practiced leaving the patient’s home and getting into his car without checking under the car or the car hood for bombs. Much like the first patient described above, this patient also exhibited an overlearned “muscle memory” for the checking behavior evidenced by a quick jerky hand movement toward the hood release latch while opening the car door. After 30 consecutive trials of getting into the car and getting out of the car without checking, the patient was able to get into his car and start the engine without experiencing distress. The patient’s behavior logs over the next 5 weeks indicated a successive decrease in car checking behavior, going 7 days in a row without checking by the last week of treatment. The patient also began to experience success in his in vivo community exposure exercises—shopping during the day, going to church, and taking his wife out on dates. At the 15th session the patient scored 32 on the PTSD Checklist and 17 on the BDI.