Under the surface: paranoid and unusual thought content are associated with depressive symptoms and suicidal ideation in adolescents entering psychiatric care

Background: Psychotic Like Experiences (PLEs), suicidal ideation, and depressive symptoms are related and common symptoms in adolescents treated in psychiatric services. However, more granular analysis of the associations between the two types of symptoms is sparse. This study aims to investigate the associations between self-reported PLEs and depressive symptoms on a sub-scale and item level, among adolescents attending secondary level psychiatric care. Methods: The sample included 328 adolescents (aged 13–18 years) attending adolescent psychiatry outpatient units of the Helsinki University Hospital. Depressive symptoms were assessed using the BDI-1A (total score and separate Suicidal Ideation item score). PLEs were assessed with the PQ-B and analysed as sum scores for the sub-scales Sensory Distortion, Grandiosity, Disorganised Speech, Paranoia, and Unusual Thoughts. Results: High scores on PQ-B subscales Paranoia and Unusual Thoughts were both independently associated with more depression and suicidality. Item analysis showed that the associations between PLEs and depression were driven by two PQ-B Paranoia subscale items, and one Unusual Thoughts subscale item. Discussion: The findings suggest that the association between PLEs and depressive symptoms is driven by paranoid experiences and unusual thought content. Professionals in psychiatric care should expect this type of co-occurrence.