Physiologic responses to loud tones in individuals with obsessive-compulsive disorder

Objective: To determine if individuals with obsessive-compulsive disorder (OCD) are characterized by larger eyeblink and/or autonomic responses to sudden, loud (startling) tones. Methods: Twenty participants with OCD and 21 mentally healthy control participants were presented with 15 consecutive 95-db, 500-msec, 1000-Hz tones with 0-msec rise and fall times at the same time orbicularis oculi clectromyogrant (EMG), heart rate (HR), and skin conductance (SC) responses were measured. Results: Participants with OCD produced larger average HR responses and a slower decline in SC responses across the 15-tone presentations. A trend for larger than average eyeblink EMG responses in participants with OCD was also observed. Conclusion: These results provide laboratory support for enhanced HR reactivity and a slower decline in SC responses to startling stimuli in individuals with OCD.