Paranoia and Social Anxiety: Structural and Temporal Relationships Across Adolescence

Background: Social anxiety and paranoia are commonly experienced during adolescence, but the nature of their co-development is largely unknown. Greater clarity could significantly advance our understanding of both conditions, and of their progression into serious mental illness. Methods: Utilising the Neuroscience in Psychiatry Network (NSPN) 2k cohort data, an accelerated cohort design study in 14-22 year olds, pre-registered hypotheses examined: (1) via measurement models, whether social anxiety and paranoia were statistically distinguishable; (2) whether social anxiety at a given time-point was significantly associated with subsequent paranoia at the next time point; and (3) common co-developmental trajectories through adolescence (e.g., low in both; high social anxiety, low paranoia, etc.). Results: (1) measurement models indicated that two and three factor models, with social anxiety and paranoia as related but separate constructs, best fit the data across all age groups, (2) in cross-lagged panel analysis, social anxiety was a more significant predictor of subsequent (approximately 1 year later) paranoia than vice versa; (3) Six common patterns in how social anxiety and paranoia developed together over time (i.e., co-developmental trajectories) were detected, whereby low levels of each were most common, followed by clusters with elevated social anxiety but not paranoia, followed by mid and descending social anxiety and mid paranoia, or elevated levels on each. Conclusions: Social anxiety and paranoia are commonly comorbid in adolescence. More evidence was obtained for the social anxiety-fueling-paranoia hypothesis than vice versa, but nonetheless we also detected a paranoia-to-social anxiety pathway in the youngest age group which requires further investigation. Understanding the social and cognitive factors that account for escalation from social anxiety into paranoia is a key future direction.