Situation: A community mental health clinic runs cognitive behavioral therapy (CBT) groups. The nurse co-leads the groups and reinforces the skills with clients between sessions. A 29-year-old woman with a fear of elevators is in systematic desensitization. She has learned diaphragmatic breathing and rated her fears on a scale of subjective units of distress (0–100): Riding 10 floors alone: 95 Riding up one floor with the nurse: 75 Standing inside an elevator with the door open: 60 Watching a video of an elevator ride: 30 Which situation should she practice FIRST?

Systematic desensitization pairs relaxation with a fear hierarchy and begins with the least feared situation, moving up only when anxiety at each step is low. Exposure to the most feared item first is flooding.

Systematic desensitization is a behavioral technique that pairs relaxation with a graduated fear hierarchy. The client has already learned diaphragmatic breathing, which serves as the relaxation response to counter anxiety. The next step is to construct and follow a hierarchy from the least anxiety-provoking situation to the most anxiety-provoking situation, practicing each step until the subjective units of distress (SUD) rating drops to a manageable level before advancing.

The client's fear ratings are as follows: watching a video of an elevator ride (30), standing inside an elevator with the door open (60), riding up one floor with the nurse (75), and riding 10 floors alone (95). The principle of graded exposure requires beginning with the item that produces the lowest distress. Therefore, watching a video of an elevator ride is the correct first step.

Exposure to the most feared item first is not systematic desensitization; it is flooding, which can overwhelm the client and increase avoidance. In systematic desensitization, the client must experience success at a low-anxiety step before moving up the hierarchy. This builds self-efficacy and prevents sensitization.

The hierarchy in this case follows a logical progression from indirect exposure to direct exposure. Watching a video is an imaginal/observational exposure that does not require physical proximity to the feared stimulus. Standing inside an elevator with the door open introduces the actual environment but retains an escape route. Riding up one floor with the nurse adds movement and height but includes a supportive presence. Riding 10 floors alone combines height, duration, and isolation, representing the highest threat level.

Key point! The order of practice is determined by the client's own SUD ratings, not by what the nurse thinks is easiest or most logical. Even if standing in an open elevator seems simple, the client rated it at 60, which is higher than the video (30). The client's subjective rating is the guide.

The use of a fear hierarchy is consistent with graded exposure principles described in the literature. In a study applying a modified fear hierarchy for movement-associated fear, items were ordered from least to most feared, and participants progressed only after demonstrating reduced fear at each level ^[1]. Similarly, case reports of systematic desensitization for radiation mask anxiety describe starting with the least threatening approximation of the feared situation before advancing to more direct contact . This stepwise approach prevents the client from becoming overwhelmed and reinforces the relaxation response as a coping tool.

Hierarchy step	SUD rating	Exposure type	Rationale for order
Watching a video of an elevator ride	30	Observational/indirect	Lowest distress; no physical proximity to elevator
Standing inside an elevator with door open	60	Direct, static	Moderate distress; escape route available
Riding up one floor with nurse	75	Direct, dynamic, supported	High distress; movement and height present
Riding 10 floors alone	95	Direct, dynamic, unsupported	Highest distress; maximum exposure

Watch out! Do not confuse systematic desensitization with flooding. Flooding involves immediate, prolonged exposure to the most feared stimulus without a gradual build-up. The question asks what to practice first, which points to the lowest item on the hierarchy, not the most challenging one.

During practice, the nurse should instruct the client to use diaphragmatic breathing before and during the video exposure. The goal is for the client to maintain a low SUD level while watching the video. Once the client can watch the video with minimal anxiety, the next step would be standing inside the elevator with the door open, and so on. The nurse reinforces the skills between sessions by reviewing the breathing technique and helping the client track SUD ratings at each step.

The effectiveness of systematic desensitization in reducing anxiety has been demonstrated across various clinical and performance contexts, including dental treatment stress in children with autism spectrum disorder and competitive anxiety in athletes . These applications share the same core mechanism: pairing relaxation with a graded hierarchy to weaken the conditioned fear response. In this elevator phobia case, the video represents the first rung of that hierarchy.