Michele Cucchi

An explorative study on metacognition in obsessive-compulsive disorder and panic disorder

OBJECTIVE To test the hypothesis that dysfunctional metacognitions might be a general vulnerability factor for anxiety disorder, metacognitive beliefs among patients with obsessive-compulsive disorder (OCD), patients with panic disorder (PD), and healthy subjects (HS) were studied. Correlations between metacognitive beliefs, OCD, and PD symptoms were also investigated. METHODS Patients with OCD (n = 114), patients with PD (n = 119), and HS (n = 101) were assessed with the Metacognition Questionnaire (MCQ). RESULTS Patients with OCD and those with PD scored significantly higher than HS on the MCQ in 2 dimensions: negative beliefs about worry concerning uncontrollability and danger as well as beliefs about the need to control thoughts dimensions. No difference in MCQ scores was observed between the OCD and PD groups. The former 2 MCQ dimensions were positively correlated with the degree of indecisiveness in patients with OCD, whereas the MCQ negative beliefs about worry positively correlated with the average intensity of anticipatory anxiety in patients with PD. CONCLUSIONS The presence of dysfunctional metacognitions in both patients with OCD and those with PD suggests that such beliefs can represent not only generic vulnerability factors for anxiety disorders but also elements that contribute to maintaining the disorder, as evidenced by their associations with aspects of OCD and PD symptoms.

Anxiety sensitivity and 35% CO2 reactivity in patients with panic disorder

OBJECTIVE The present study examines the possible relationships between anxiety sensitivity (AS) and reactivity to the 35% carbon dioxide (CO(2)) challenge in panic disorder (PD). METHODS One-hundred eight patients with PD underwent the 35% CO(2) challenge and completed the Anxiety Sensitivity Index (ASI). Multiple regression analyses were applied to evaluate the role of AS as a predictor of CO(2)-induced anxiety. RESULTS Fifty-six patients with PD showed high AS scores, whereas 48 showed medium scores and 4 low scores. ASI scores significantly predicted symptomatological reaction to CO(2) but not subjective induced anxiety. CONCLUSION These findings suggest that the fear of anxiety-related bodily sensations was related to the symptomatological reactivity to CO(2) but did not seem to play a crucial role in the modulation of the subjective anxiogenic/panicogenic response to hypercapnia in patients with PD.

Lack of relationship between CO2 reactivity and serotonin transporter gene regulatory region polymorphism in panic disorder

Changes in the function of the serotonergic system influence both panic phobic symptoms and carbon dioxide (CO2) reactivity in patients with panic disorder. Schmidt et al. [2000: J Abnorm Psychol 109(2):308–320] recently reported a predictive role of the genetic variants of the 5‐HTTLPR on the fearful response to CO2 in healthy controls. We tested the hypothesis that the heterogeneity of CO2 reactivity in patients with panic disorder could be related to the allelic variation of the 5‐HTT promoter. Ninety‐five patients with panic disorder were challenged with 35% CO2. 5‐HTTLPR allelic variation in each subject was determined using a PCR‐based method. There were no differences for all the measures of CO2 reactivity among the genotype groups. CO2 reactivity of patients with panic disorder seems not to be influenced by the genetic variants of the 5‐HTTLPR; this finding does not support a role for the serotonin transporter in the etiopathogenesis of CO2 reactivity in panic disorder.

Vulnerability to 35% CO2 of panic disorder patients with a history of respiratory disorders

Patients with panic disorder often report a history of respiratory pathology. Furthermore, panic disorder patients are vulnerable to CO2 challenges. The increased CO2 vulnerability displayed by panic disorder patients may be related to lifetime respiratory pathology. We examined whether panic disorder patients with a history of respiratory disorders are more vulnerable to a 35% CO2 challenge than those without such a history. Ninety-six patients with panic disorder were interviewed about their lifetime respiratory status (asthma, bronchitis and various other respiratory conditions) and underwent the challenge. Immediately before and after the CO2 inhalation, the patients filled out the Visual Analogue Scale for Anxiety (VAS-A) and the Panic Symptom List (PSL). We found no differences between the two panic disorder groups on anxiety (VAS-A), panic symptoms (PSL) or panic attacks after the CO2 challenge. Our results suggest that having a PD is an important factor in CO2 vulnerability independent of a history of respiratory disorders.

Neural correlates of anxiety sensitivity in panic disorder: A functional magnetic resonance imaging study

Panic disorder has been associated with dysfunctional neuropsychological dimensions, including anxiety sensitivity. Brain-imaging studies of the neural correlates of emotional processing have identified a network of structures that constitute the neural circuitry for emotions. The anterior cingulate cortex (ACC), medial prefrontal cortex (mPFC) and insula, which are part of this network, are also involved in the processing of threat-related stimuli. The aim of the study was to investigate if neural activity in response to emotional stimuli in the cortico-limbic network is associated to anxiety sensitivity in panic disorder. In a sample of 18 outpatients with panic disorder, we studied neural correlates of implicit emotional processing of facial affect expressions with a face-matching paradigm; correlational analyses were performed between brain activations and anxiety sensitivity. The correlational analyses performed showed a positive correlation between anxiety sensitivity and brain activity during emotional processing in regions encompassing the PFC, ACC and insula. Our data seem to confirm that anxiety sensitivity is an important component of panic disorder. Accordingly, the neural underpinnings of anxiety sensitivity could be an interesting focus for treatment and further research.

Comparison of 35% carbon dioxide reactivity between panic disorder and eating disorder

Patients with panic disorder (PD) are hyperreactive to carbon dioxide (CO(2)), but the specificity of this characteristic to PD is controversial. Anxiety and phobic symptomatology are common to both panic and eating disorders (ED). To investigate the specificity of CO(2) hyperreactivity to PD, the responses to inhalation of a 35% CO(2) and 65% oxygen (O(2)) gas mixture were assessed. Reactions to 35% CO(2) challenge were compared among three groups of age- and sex-matched subjects: 14 patients with ED, 14 patients with PD, and 14 healthy controls (HC). A double-blind, randomized, crossover design was used. Only patients with PD showed a strong reaction to 35% CO(2), while patients with ED and HC did not react significantly. The results support the specificity of CO(2) hyperreactivity to PD.

Anxiety sensitivity and modulation of the serotonergic system in patients with PD

Anxiety sensitivity, i.e., the fear of anxiety-related bodily sensations, is one of the most studied cognitive variables in panic disorder (PD). However, the effects of selective serotonergic antipanic agents on this variable have not yet been investigated. The present study examines the effects of 6 weeks of treatment with citalopram on anxiety sensitivity in patients with PD. Twenty patients entered the study. On day 0, before starting drug treatment, after 1 week and after 6 weeks of treatment, each patient was evaluated with the Anxiety Sensitivity Index (ASI); the severity of clinical symptomatology was assessed with standardized psychometric scales. Results showed a significant reduction of anxiety sensitivity after 6 weeks of treatment. There was a significant correlation between decrease of anxiety sensitivity and anticipatory anxiety, while no correlations were found between panic attacks and agoraphobic avoidance. These results suggest that antipanic drug treatment decreases anxiety sensitivity.