Modifying avoidance in social anxiety: The effects of a cognitive-behavioural instruction on extinction learning.

Although cognitive-behavioural therapy (CBT) with exposure is the first-line treatment for Social Anxiety Disorder (SAD), its efficacy is lower for SAD than for other anxiety disorders. One possible reason is that CBT may not effectively target the key maintaining features of SAD: persistent avoidance and heightened threat expectancy. Experimental research shows that individuals with elevated social anxiety exhibit generalised avoidance and persistent threat beliefs in conditioning paradigms, yet it remains unclear whether brief cognitive-behavioural (CB) strategies can modify these fear responses. Clarifying which components of fear responding, behavioural, cognitive, and physiological, are amenable to brief CB-based instruction is critical for identifying the mechanisms through which CBT with exposure facilitates change and for improving the precision of treatment. This study examined the effect of a brief CB instruction on behavioural avoidance, threat expectancy, and autonomic arousal in individuals with elevated social anxiety. Eighty-eight adults were assigned to a CB-informed instruction (n = 44) or control instruction (n = 44) condition while completing a four-phase Pavlovian Conditioning paradigm: threat acquisition, US-avoidance acquisition, US-avoidance extinction, and extinction test. Social anxiety was modelled dimensionally using SPIN scores. Behavioural avoidance, skin conductance response (SCR; autonomic arousal), and US-expectancy ratings (cognitive threat prediction) were assessed throughout. Results showed that, higher social anxiety was associated with greater avoidance and persistent threat responding. Further, among individuals with elevated social anxiety, the CB instruction was associated with reduced avoidance behaviours during US-avoidance extinction but did not alter SCRs or threat expectancy during extinction testing. These findings suggest that a brief CB instruction can attenuate maladaptive avoidance without corresponding changes in autonomic or cognitive threat responses for individuals with higher social anxiety. This dissociation provides a novel, mechanistic account of how brief cognitive-behavioural strategies selectively modify components of fear responding, offering valuable insights for the development of more targeted and effective exposure-based interventions for SAD.