How Can We Better Understand and Measure Maladaptive Avoidance Behavior?

What you need to know

• Excessive avoidance behavior is a core feature of anxiety disorders but is poorly understood and difficult to measure objectively
• Maladaptive avoidance may be driven by three processes: heightened threat appraisal, habitual avoidance, and trait avoidance tendency
• New research approaches are needed to better differentiate these processes and understand avoidance across anxiety disorders
• Improved measurement of avoidance could lead to more targeted interventions for anxiety

Understanding Excessive Avoidance in Anxiety Disorders

Imagine you’re afraid of dogs. You might cross the street to avoid walking past someone with a dog, even if it’s on a leash and doesn’t seem aggressive. While this avoidance behavior reduces your anxiety in the moment, it prevents you from learning that most dogs are not actually dangerous. Over time, this pattern of avoidance can significantly limit your daily activities and quality of life.

This type of excessive avoidance is a hallmark of anxiety disorders, post-traumatic stress disorder (PTSD), and obsessive-compulsive disorder (OCD). It’s a major factor that maintains anxiety over time. However, scientists still don’t fully understand the brain mechanisms underlying maladaptive avoidance or have great ways to measure it objectively.

In a new paper, researchers Tali M. Ball and Lisa A. Gunaydin review the current state of avoidance research and propose new directions to advance our understanding. They argue that maladaptive avoidance likely stems from three key processes:

1. Heightened threat appraisal - overestimating the level of danger
2. Habitual avoidance - avoidance that has become an automatic habit
3. Trait avoidance tendency - an innate predisposition to avoid

By developing ways to tease apart these processes, we may be able to better understand excessive avoidance and develop more targeted treatments.

Current Research Approaches

Most laboratory studies of avoidance behavior use paradigms that measure adaptive avoidance - avoiding a genuinely dangerous stimulus. For example, in rodent studies, animals might learn to move to a safe area when they hear a tone that predicts an electric shock.

These studies have revealed some key brain regions involved in avoidance behavior, including:

• The medial prefrontal cortex, involved in decision-making and regulating emotions
• The amygdala, which processes threat and fear
• The striatum, important for learning and habits

However, to understand maladaptive avoidance, researchers need paradigms that measure avoidance of relatively safe stimuli or avoidance that leads to negative consequences.

Promising Paradigms for Studying Maladaptive Avoidance

The authors highlight a few promising research approaches for investigating excessive avoidance:

Extinction-Resistant Avoidance

In these studies, animals or humans first learn to avoid a stimulus paired with an unpleasant outcome. Then, the unpleasant outcome is removed, but researchers measure whether avoidance behavior persists. This models situations where people continue avoiding something even after it’s no longer dangerous.

Interestingly, some studies find that avoidance can persist even when fear responses (like increased heart rate) have diminished. This suggests avoidance can become disconnected from fear and may be driven by habit.

Avoidance Generalization

These paradigms examine how avoidance of one stimulus generalizes to similar but safe stimuli. For example, in the “virtual farmer” task, humans learn to avoid a shape paired with a shock. Researchers then measure if they also avoid similar shapes, even though these were never paired with shock.

This models how someone with PTSD after a car accident might avoid not just the intersection where the crash occurred, but driving altogether.

Competing Rewards

Another strategy is to pit avoidance against a competing reward. This captures real-world situations where avoidance leads to missed positive opportunities.

For instance, in some tasks, avoiding a potential threat means forgoing a monetary reward. This allows researchers to measure how much reward someone is willing to give up to avoid a perceived threat.

Gaps in Knowledge and Future Directions

While these paradigms are promising, the authors argue several key issues need to be addressed to advance the field:

1. Differentiating underlying processes: Most current tasks don’t clearly distinguish whether excessive avoidance is driven by heightened threat perception, habit, or trait tendency. Developing paradigms that can tease these apart is crucial.

2. Translating across species: Animal studies provide more precise information about brain mechanisms, while human studies can assess subjective experiences. Aligning paradigms across species will help connect these insights.

3. Testing in clinical populations: Most avoidance paradigms haven’t been tested in people with anxiety disorders. Doing so is essential to understand how lab findings relate to real-world excessive avoidance.

4. Improving diagnosis and treatment: Ultimately, the goal is to develop reliable ways to measure avoidance in individuals and use this to guide treatment. Different underlying processes may respond best to different interventions.

Conclusions

• Excessive avoidance is a key feature of anxiety disorders that maintains symptoms over time
• New research approaches are needed to understand the brain mechanisms of maladaptive avoidance
• Distinguishing between heightened threat perception, habit, and trait avoidance tendency is crucial
• Improved measurement of avoidance could lead to more targeted, effective anxiety treatments

By tackling these research challenges, scientists hope to gain a deeper understanding of maladaptive avoidance. This could ultimately lead to better ways to assess and treat this core feature of anxiety disorders, improving outcomes for millions of people struggling with excessive avoidance behaviors.