Variables Associated With Non-Response in Anxiety and Depression Among Patients Receiving Treatment in a Partial Hospitalization Program.

Objective: A meaningful portion of patients receiving psychological treatment do not respond to treatment. Identifying variables associated with non-response may allow clinicians to better predict who is less likely to respond, and alter treatment procedures accordingly. Therefore, this study aimed to characterize patients who did not respond to treatment in a partial hospitalization program and identify baseline variables that are most predictive of non-response.

Methods: Variables were compared between responders and non-responders using chi-square tests of independence and independent samples t-tests. Two logistic LASSO regression models were conducted to separately identify variables associated with treatment non-response in a sample of patients with elevated anxiety or depression, respectively.

Results: 24.8% of patients with elevated anxiety symptoms were classified as anxiety non-responders (n = 315), while 36.3% of patients with elevated depression symptoms were classified as depression non-responders (n = 445). Non-responders in both groups were characterized by greater clinical severity at baseline and discharge. Non-response in both groups was predicted by more comorbid diagnoses, greater functional impairment at baseline at discharge, and a greater number of treatment days attended and missed.

Conclusion: These results suggest that patients with greater levels of clinical severity, more functional impairment, and a greater number of absences were less likely to respond to PHP treatment. It is important to replicate these findings in independent samples to further examine what variables may be associated with non-response in this treatment setting, and therefore identify clinical strategies to reduce this phenomenon.