Trajectories of Treatment Response and Nonresponse in Youth at High Risk for Suicide

Abstract

Objective: To examine trajectories of treatment response in suicidal youth who participated in a randomized controlled trial comparing dialectical behavior therapy (DBT) and individual and group supportive therapy.

Method: Using latent class analysis across both treatment conditions, secondary analyses were conducted of data from a multisite randomized controlled trial comprising 173 youths ages 12-18 with repetitive self-harm (SH) (including ≥1 lifetime suicide attempts) and elevated suicidal ideation (SI). The sample was 95% female, 56.4% White, and 27.49% Latina. Participants received 6 months of DBT or individual and group supportive therapy and 6 months of follow-up. Primary outcomes were SH and SI.

Results: Of the sample, 63% and 74% were members of latent classes that showed improvement in SI and SH, respectively; 13% were total nonresponders, with no improvement in SI or SH. SH nonresponse emerged at the midpoint of treatment (3 months), with nonresponders showing a sharp increase in SH over the remainder of treatment and follow-up. Youth receiving DBT were significantly more likely to be an SH responder vs nonresponder than youths in individual and group supportive therapy (ꭓ²₁ = 6.53, p = .01). An optimal threshold cut point using multivariate predictors of total nonresponse (White, externalizing symptoms, total SH, and SI) predicted total nonresponders to DBT with 100% accuracy.

Conclusion: This is the first study to identify trajectories of both SI and SH response to treatment in a sample of adolescents at risk of suicide. Results may inform personalized treatment approaches.

Clinical trial registration information: Collaborative Adolescent Research on Emotions and Suicide (CARES); https://www.

Clinicaltrials: gov/; NCT01528020.

Keywords: adolescent; dialectical behavior therapy; nonsuicidal self-injury; self-harm; suicide.

Figure 1:. Five Latent Classes for Suicidal Ideation

Note: Each graph shows the individual trajectories for each youth within the identified latent classes along with the smoothing spline average trajectory within each class, where the smoothing spline represents the average continuous trajectory over time using the individual trajectories rather than the descriptives of the available data at each point. SIQ = Suicidal Ideation Questionnaire.

Figure 2:. Five Latent Classes for Self-Harm

Note: Each graph shows the individual trajectories for each youth within the identified latent classes along with the smoothing spline average trajectory within each class, where the smoothing spline represents the average continuous trajectory over time using the individual trajectories rather than the descriptives of the available data at each point.

Figure 3:

Trajectories of Response and Non-Response for Suicidal Ideation (SI), Self-Harm (SH) and SI + SH Groupings

Figure 4:. Prediction of the Optimal Threshold for the Total Sample

Note: The black curve represents the optimal operating point (OOP). Subjects are divided into high self-harm (SH) (≥ 25) and low SH (≤ 24) at baseline, with the Child Behavior Checklist (CBCL) Externalizing t-score on the x-axis and the Suicidal Ideation Questionnaire, junior (SIQ-Jr.) score on the y-axis. Adolescents predicted as total non-responders are indicated by the red dots, where the blue dots represent responders. Total non-responder status can be predicted by plotting the ordered pair. If the ordered pair lies on the black curve or in the same region as the red dots, then the patient is predicted to be a total non-responder. For example, an adolescent with a CBCL Externalizing t-score = 60, SIQ-Jr. = 40 and high SH is in the responder region.