O3.3. DO DEPRESSIVE SYMPTOMS MEDIATE THE RELATIONSHIPS BETWEEN SUICIDAL IDEATION AND PSYCHOTIC EXPERIENCES IN ADOLESCENTS?
Authors: Campos Susana , Monjes Pía , Wigman Johanna , Nunez Daniel 
Published: May 2020

Abstract

Background
Youth mental health is a global challenge, with onset of mental illness peaking in adolescence. In this population, depressive symptoms (DS), psychotic experiences (PE) and suicidal ideation (SI) are prevalent and risk factors for future mental disorders. DS could mediate relationships between psychotic experiences (PE) and suicidal ideation (SI); however, its precise role in this association remains uncertain. We examined whether depressive symptoms mediate the association between psychotic experiences and suicidal ideation using two complementary approaches to cross-sectional data from a community sample of adolescents. We hypothesized that DS mediate relationships between PE and SI. Additionally, we expected to find that specific DS would play a central role in this association and that this would show via higher centrality values for affective symptoms reflecting low energy, hopelessness and self-depreciating feelings in the network analyses.

Methods
We examined cross-sectional relationships between PE, SI and DS in a community sample of adolescents (N= 1715; 13–19 years old) recruited from Chilean secondary schools between April and August 2015. We addressed depressive symptoms (DS) using the Depression and Anxiety Scale (DASS-21). We assessed suicidal ideation using 6 items of the Columbia Suicide Severity Rating Scale (C-SSRS), adapted for being used as a self-report questionnaire. We addressed psychotic experiences (PE) by items of two pre-existing scales we adapted in prior studies with adolescents: the Community Assessment of Psychic Experiences - Positive scale (CAPE-P15), and the Brief Self-report Questionnaire for Screening Putative Pre-psychotic States (BQSPS). We first conducted a mediation analysis, where PE was the predictor, SI was the outcome, and DS were the mediator variables. Next, we performed a network analysis and estimated the strength centrality index for each symptom, and the network robustness through accuracy and stability test.

Results
Pearson’s correlations showed significant associations between all the variables in (SI-DS: r= .491, p&lt;.001; PE-SI: r= .436, p&lt;.001; PE-DS: r= .617, p&lt;.001). No demographic variables (i.e gender, age) had to be controlled for in the mediation.
The mediation analysis yielded that depression mediates the relationship between PE and SI (b= .2206, 95% BCa CI [.1783, .2644]). Additionally, network analysis showed the following strength centrality values (SV): depression (mean= 5.92, σ2=1.72; median= 6.08); bizarre experiences (mean= 3.94, σ2=0.35; median= 4.02); perceptual anomalies (mean= 3.75, σ2=2.21; median= 3.75); social anxiety (mean= 3.49, σ2=0.79; median= 3.23); negative symptoms (mean= 3.32, σ2=.23; median= 3.49). SI was strongly connected to pessimism (SV= .69); social anxiety (SV= .41); and self-criticalness/worthlessness (SV= .39). The correlation stability coefficient for the strength was (cor = 0.7) = 0.672, suggesting robustness of the findings.

Discussion
Our findings support prior research showing that DS mediate relationship between PE and SI and adds to this literature by showing which symptoms in particular are important. Some specific depressive symptoms having a central role in this process (pessimism and worthlessness) and also psychotic experiences (social anxiety: being distant to people) and perceptual anomalies (seeing things other cannot) are connected in a meaningful way to suicidal ideation in a community sample of adolescents. These findings should be considered when planning early detection/intervention programs.