Testing anxiety and reward processing in anorexia nervosa as predictors of longitudinal clinical outcomes

Anorexia nervosa (AN) is a psychiatric disorder with a tenuous longitudinal course marked by a high risk of relapse. Previous studies suggest that aberrant threat perception and reward processing operate in many with AN, and may produce obstacles to treatment engagement; therefore, these could potentially represent predictors for longitudinal clinical outcomes. In this study, anxiety and reward symptoms, behaviors, and neural circuit connectivity were measured in intensively treated AN-restrictive subtype patients (n = 33) and healthy controls (n = 31). Participants underwent an fMRI experiment using a monetary reward task in combination with either overlapping individually tailored anxiety-provoking words or neutral words. Behavioral/psychometric measures consisted of reaction times on the monetary reward task and self-ratings on anxiety symptoms at study entry. We tested multimodal, multivariate models based on neural, behavioral, and psychometric measures of reward and anxiety to predict physiological (Body Mass Index; BMI) and psychological (eating disorder symptom severity) longitudinal outcomes in AN over six months. Our results indicated that higher anxiety symptom psychometric scores significantly predicted BMI reductions at follow-up. Untreated anxiety after intensive treatment could put individuals with AN at heightened risk for weight loss. This represents a potentially modifiable risk factor that could be targeted more aggressively to help reduce the chance of future clinical worsening. •Robust multimodal prediction models have the potential to identify patients susceptible to future clinical worsening.•We found that heightened anxiety in adolescents with anorexia nervosa predicted lower BMI longitudinally.•Residual anxiety after intensive treatment may be a modifiable risk factor that could be specifically targeted in treatment.