Understanding adolescent anxiety disorders through the lens of decision science: towards a mathematical psychiatry

Abstract

Anxiety disorders are the most common class of mental disorder among children and adolescents and cause significant impairment and distress. A decision science model of anxiety is presented that explains two hallmark characteristics of anxiety disorders, worry and avoidance. In a Rational Choice Theory (RCT) paradigm, anxious worry results from extreme beliefs about either the probability of certain outcomes materializing, or the subjective utility associated with those outcomes. These correspond to fatalistic and catastrophizing presentations of anxiety. In a Fear Learning paradigm, anxious avoidance is the result of a lowered conditioning threshold or a heightened tendency to generalize conditioned behavior. This presents as avoidance of the conditioned stimulus. The current suite of treatment options for anxiety disorders already reflects this model to a considerable extent. For mild-to-moderate presentations, the first line treatment is Cognitive Behavioral Therapy (CBT), in particular, the exposure-based variations of CBT that have been developed for anxiety disorders. For severe presentations, or when psychotherapy alone fails to achieve the desired result, CBT should be supplemented with pharmacotherapy. SSRIs are the primary class of drugs that should be considered. Evidence does not support the use of anxiolytics for pediatric anxiety. Treatment planning should account for both symptom severity and the degree of impairment caused by the symptoms. The decision science model highlights negative, self-perpetuating cycles of anxious beliefs and behavior, and suggests multiple ways to improve current treatments by focusing on the processes of learning and belief