A Latent Trajectory Analysis of Inpatient Depression Treatment

Patients seeking psychotherapy may progress through treatment in varying ways. Modeling multiple treatment trajectories through growth mixture modeling provides a comprehensive way of understanding a patient population. Multiple trajectories may additionally help researchers describe complexities within a patient population, such as those with severe and persistent disorders and comorbid symptoms, to understand characteristics of patients that may be struggling during treatment. We analyzed the depression symptom outcome measures (PHQ-9) for 246 patients receiving inpatient depression treatment. We constructed a growth mixture model of depression symptom changes, allowing the number of treatment trajectories to emerge through the data, and utilized goodness-of-fit indices to select the superior model. Results indicated three classes was the best fitting model, with patients either (a) patients started above the clinical cutoff score for depression and had significant linear change over time, ending therapy just above the clinical cutoff-"Improvement-leveling off-improvement"; (b) patients started therapy well above the clinical cutoff, showed symptom alleviation at the beginning of therapy before the trajectory started to level off-"High symptom pressure"; or (c) patients started therapy just below the clinical cutoff, had steady change throughout therapy, ending well below the clinical cutoff-"continuous improvement." Implications of the study may include altering the length of treatment based on patient presenting symptoms in order to best serve patients and utilize hospital resources. Clinical Impact Statement Question: The study addressed how the outcomes of patients who received inpatient depression treatment change over the course of therapy. Findings: Patients with depression who responded quickly to inpatient treatment may need less time in treatment than those who additionally experienced a combination of emotional distress, fear of compassion, and PTSD symptoms, where longer treatment and attention to comorbid symptoms may be beneficial. Meaning: The study provided an initial rationale for the potential reallocation of therapeutic resources to maximize treatment efficacy, as well as understanding the complex needs of patients with depression who initially deteriorated during inpatient treatment. Next Steps: In addition to the treatment recommendations to the hospital administration and treatment team, we aim to conduct a follow-up study to monitor efficacy and encourage future latent class analyses of inpatient treatment.