Health anxiety amplifies fearful responses to illness-related imagery.

Severe health anxiety (HA) is characterized by excessive worry and anxiety about one's health, often accompanied by distressing intrusive imagery of signs of a serious illness or potentially receiving bad news about having a life-threatening disease. However, the emotional responses to these illness-related mental images in relation to HA have not been fully elucidated. Emotional responses to mental imagery of 142 participants were assessed in a well-controlled script-driven imagery task, systematically comparing emotional responses to illness-related imagery with neutral and standard fear imagery. The results revealed that participants reported higher anxiety, aversion, emotional arousal, and a stronger avoidance tendency during imagery of fear and illness-related scenes compared to neutral scenes. Importantly, the emotional modulation varied by the level of HA, indicating that individuals with higher HA experienced stronger emotional responses to illness-related imagery. This association between HA and fearful imagery could not be better accounted for by other psychological factors such as trait anxiety, anxiety sensitivity, somatic symptom severity, or symptoms of depression and anxiety. Fearful responding to standard threat material was not associated with HA. The present findings highlight the importance of considering fear responding to mental imagery in understanding and addressing HA.

Interoceptive threat leads to defensive mobilization in highly anxiety sensitive persons.

To study defensive mobilization elicited by the exposure to interoceptive arousal sensations, we exposed highly anxiety sensitive students to a symptom provocation task. Symptom reports, autonomic arousal, and the startle eyeblink response were monitored during guided hyperventilation and a recovery period in 26 highly anxiety sensitive persons and 22 controls. Normoventilation was used as a non-provocative comparison condition. Hyperventilation led to autonomic arousal and a marked increase in somatic symptoms. While high and low anxiety sensitive persons did not differ in their defensive activation during hyperventilation, group differences were detected during early recovery. Highly anxiety sensitive students exhibited a potentiation of startle response magnitudes and increased autonomic arousal after hyper- as compared to after normoventilation, indicating defensive mobilization evoked by the prolonged presence of feared somatic sensations.

Individual differences in fear-potentiated startle as a function of resting heart rate variability: implications for panic disorder.

BACKGROUND: Anticipatory anxiety, which can be indexed by the startle potentiation to a threat of shock, has been implicated in the development of panic disorder. Large individual differences exist in startle potentiation to threat of shock but few differences have been found between panic patients in general and non-anxious controls. The present studies explored resting heart rate variability (HRV) as a source of individual differences in startle potentiation in students at risk for panic disorder and in unmedicated panic patients. METHODS: Participants in Study 1 were 22 students high and 21 students low in anxiety sensitivity (AS). Nine unmedicated panic patients and 15 matched non-anxious controls were included in Study 2. Startle potentiation to the threat of shock was examined as a function of AS (Study 1) and diagnostic category (Study 2) as well as resting HRV. RESULTS: Whereas no differences in startle potentiation were found as a function of AS or panic disorder diagnosis in general, both studies revealed that low resting HRV was associated with exaggerated startle responses to the threat of shock. CONCLUSIONS: The present results replicate and extend the sparse literature on fear-potentiated startle in panic disorder. Low HRV was associated with more pronounced startle potentiation to both explicit and contextual cues. Thus, low HRV may be a useful endophenotype for at least some anxiety disorders.