Loneliness and Psychotic Symptoms: The Mediating Role of Depression

Psychotic symptoms have been shown to be associated with numerous social factors, such as migration and urban upbringing, of which one plausible common component is loneliness. This suggests a relationship between loneliness and positive psychotic symptoms. According to current cognitive models of psychosis, the relationship between loneliness and positive symptoms is likely to be explained by affective states. The current study examined the cross-sectional relationship between loneliness, depression, and positive symptoms in four separate community samples (combined N = 766) with regression based mediation analysis and network analysis. The results showed that depression completely mediated the relationship between loneliness and positive symptoms in three out of four samples. Partial mediation was found in one sample. Network analysis revealed that loneliness, depression, and positive symptoms clustered separately and that there was a unique connection between loneliness and items that assess paranoid beliefs, in the sense that loneliness was not found to be connected to other psychotic symptoms, such as hallucinations. As expected, loneliness is related to positive symptoms and depression played a strong role in explaining the association. Thus, early interventions of psychosis that target loneliness are likely to be beneficial, especially if these interventions additionally target depression. Furthermore, the specific connection of loneliness and paranoid beliefs supports the theory that specific adversity leads to specific psychotic symptoms.