Panic disorder and vestibular/equilibrium dysfunctions: state of the art

This paper reviews the literature on the links between panic disorder with or without agoraphobia and vestibular dysfunction. To date, it has been established that these conditions are encountered in high proportions in psychiatric samples and in patients consulting for equilibrium problems. Three models have tried to hypothesize the mechanisms underlying this co-occurrence. Agoraphobic avoidance and high anxiety level seem to be characteristics of individuals affected by both conditions. Moreover, vestibular dysfunctions appear to be predicted by individuals feeling uncomfortable in situations characterized by spatial and/or motor particularities. Additional studies on that topic would be beneficial. Further studies should try to better understand people with both panic disorder and dysfunctions of the equilibrium system. These individuals who suffer from both conditions may avoid activities that particularly call upon the equilibrium system, such as walking on uneven surfaces or undertaking some forms of transportation. The cognitive substrates pertaining to the feared consequences of the physical symptoms may also differentiate this group from uncomplicated anxiety disorder patients. For example, these individuals with uncomplicated panic disorder may fear having a heart attack or suffocating as a result of a panic attack, whereas individuals suffering from both conditions may be more prone to apprehending falling or vomiting. The paper also proposes (1) the analysis of characteristics of individuals in remission from both conditions so that effective components of treatment are emphasized, and (2) targets for treatment for these comorbid patients.     

Panic disorder

In this article, the authors review the most recent advances in the pharmacotherapy, psychotherapy, and combined therapy for panic disorder. The authors focus on peerre-viewed data and on pragmatic clinical approaches that may help patients suffering from panic disorder.     

Panic disorder: the role of the balance system

Experimental evidences suggest that Panic Disorder (PD) is characterized by abnormalities in respiratory and vestibular functions. We studied balance system function in patients with PD and its relationships with CO(2) reactivity and clinical characteristics. Nineteen patients with PD with/without agoraphobia underwent static posturography and the 35% CO(2) challenge. The severity of clinical symptomatology was measured by standardized psychometric scales. Patients were free of psychotropic medications during the 2 weeks before the study. Different investigators blind to each other carried out the CO(2) challenge, static posturography and clinical assessment. Nineteen age and sex-matched healthy controls underwent static posturography. Body sway velocity and length were significantly higher in panic patients than in controls and patients showed high percentages of abnormal scores. Patients with two or more abnormal scores on static posturography were significantly more agoraphobic than those with less than two. Abnormal posturography scores under the eyes-opened was related to high anticipatory anxiety, whereas those under eyes-closed was related to phobic avoidance. Symptomatological reactivity to CO(2) was significantly correlated to abnormal functions of the balance system in the eyes-closed condition. Our findings suggest that (1) many patients with PD (5-42%) have abnormalities in their balance system function compared with healthy controls (0-5%), (2) symptomatological reactivity to CO(2) and balance system function in patients with PD are correlated only in the eyes-closed condition and (3) there is a significant link between agoraphobic avoidance and subclinical abnormal function of the balance system network.     

Panic disorder and mortality

Evidence so far indicates two sources for excess mortality in panic disorder--suicide and cardiovascular morbidity. The risk for eventual suicide may rival that for primary depression, but the predictors and the necessary antecedents probably differ. The lapse between diagnosis and suicide may be larger for panic disorder, and complications such as secondary depression and substance abuse may be necessary. There are few well-established predictors for primary depression despite many relevant studies. The risk for suicide in panic disorder is barely recognized, and established predictors are accordingly remote. One study has demonstrated excess cardiovascular mortality among males with panic disorder, and another from the same center has provided weak support. Only one additional study has provided the necessary detail as to sex and cause, and those findings were quite supportive, although the subjects may have been mixed diagnostically. There are numerous feasible explanations for excess cardiovascular mortality in panic disorder and even some reason to believe that successful treatment might lessen it. To so advise patients would be not only premature at this point but unnecessary and countertherapeutic--unnecessary because these patients are motivated by discomfort to seek treatment and countertherapeutic because cardiovascular morbidity is what many of these patients pathologically fear. Rather, the findings suggest focus for future study. The initial findings of excess cardiovascular morbidity in males badly need replication, as do the more recent findings of Kahn et al. Likewise, animal models may reveal some of the pathophysiologic mechanisms at work. It is hoped that these efforts will converge in the not-too-distant future.     

Panic disorder and hyperventilation

Respiratory abnormalities are associated with anxiety, particularly with panic attacks. Symptoms such as shortness of breath, "empty-head" feeling, dizziness, paresthesias and tachypnea have been described in the psychiatric and respiratory physiology related to panic disorder. Panic disorder patients exhibit both behaviorally and physiologically abnormal responses to respiratory challenges tests. OBJECTIVE: We aim to observe the induction of panic attacks by hyperventilation in a group of panic disorder patients (DSM-IV). METHOD: 13 panic disorder patients and 11 normal volunteers were randomly selected. They were drug free for a week. They were induced to hyperventilate (30 breaths/min) for 3 minutes. Anxiety scales were taken before and after the test. RESULTS: 9 (69.2%) panic disorder patients and one (9.1%) of control subjects had a panic attack after hyperventilating (p < 0.05). CONCLUSION: The panic disorder group was more sensitive to hyperventilation than normal volunteers. The induction of panic attacks by voluntary hyperventilation may be a useful and simple test for validating the diagnosis in some specific panic disorder patients.     

Panic disorder and school refusal

This article provides clinical and research information about panic disorder, agoraphobia, and school refusal. Proposed changes to the definition of panic disorder and agoraphobia for the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition are outlined. Treatment of panic disorder, and school refusal in children and adolescents is also discussed.     

Panic disorder and idiopathic cardiomyopathy

OBJECTIVE: This study investigated whether, among a population of cardiac patients, there is a preferential association between idiopathic cardiomyopathy (CMP) and Panic Disorder (PD). METHODS: A total of 93 patients with cardiac failure, 50 of them with CMP, 43 with other cardiac diseases, underwent a standard psychiatric examination using the MINI neuropsychiatric interview. RESULTS: While half of the subjects met the criteria for a psychiatric disorder, PD was no more prevalent in the CMP group compared to other patients. CONCLUSION: This study confirms the high prevalence of psychiatric pathology, particularly anxiety, mood, and alcohol-related disorders, in patients with cardiac failure. However, previous findings on the specific association between CMP and PD could not be replicated.     

Panic disorder and alcoholism]

Relationships between alcoholism and anxiety disorder are well known by clinicians. Studies have recently shown that the prevalence of alcohol abuse or dependence is very high in patients with panic disorder with or without agoraphobia (Thyer et al., 1986; Bibb and Chambless, 1986). The aims of this study were to determine the prevalence and comorbidity of alcohol abuse and dependence in a population of panic outpatients who were consecutive referrals for treatment of panic disorder (PD) in an anxiety clinic. Patients were interviewed with the Schedule for Affective Disorders and Schizophrenia-Lifetime Version Modified for the study of anxiety disorders (SADS-LA) which is a standardized and semi-structured interview allowing to make diagnoses according to RDC, DSM III and DSM III-R criteria. One hundred and three panic patients (39 males and 64 females) were included in the study. Their mean age was 38.5 years (SD: 11.6). In this sample, 24.3% met the DSM III-R criteria for alcohol abuse and 8.7% those for alcohol dependence. Among these patients, 26.2%, abused of benzodiazepines and 16.5% of them of other substances. We found a high comorbidity rate. In fact, 6.8% of the patients met diagnostic criteria for PD alone, 31.0% for one more diagnosis, 29.1% for two more and 33.0% for three or more besides PD. In this study, we found an association between alcohol abuse and the presence of a lifetime diagnosis of major depressive episode and/or other addictive behaviors. Otherwise, alcohol abuse did not occur more often in patients suffering from panic disorder associated with agoraphobia and/or social phobia.     

Panic disorder and the Defence Mechanism Test

The aim was to study defence categories according to the modified version of the Defence Mechanism Test (DMTm) and to see if there was a relationship between DMTm and severity of illness. The material consists of 23 patients with panic disorder according to DSM-III-R who participated in a long-term follow-up of two clinical trials. The most common defence categories were repression, denial, disavowal or denial of the threat relation or of the identity of the peripheral person. The patients with denial or polymorphous identification had more severe symptoms and the latter group also were more handicapped by their symptoms. Denial and disavowal or denial of the threat relation may be defence categories, which are not so effective in preventing the individual from experiencing anxiety. Polymorphous identification, although not so common, does not seem to be an appropriate defence among patients with panic disorder.     

Panic disorder and the Defence Mechanism Test

The aim was to study defence categories according to the modified version of the Defence Mechanism Test (DMTm) and to see if there was a relationship between DMTm and severity of illness. The material consists of 23 patients with panic disorder according to DSM-III-R who participated in a long-term follow-up of two clinical trials. The most common defence categories were repression, denial, disavowal or denial of the threat relation or of the identity of the peripheral person. The patients with denial or polymorphous identification had more severe symptoms and the latter group also were more handicapped by their symptoms. Denial and disavowal or denial of the threat relation may be defence categories, which are not so effective in preventing the individual from experiencing anxiety. Polymorphous identification, although not so common, does not seem to be an appropriate defence among patients with panic disorder.     

Panic disorder in the medically ill

The authors describe five patients with concurrent panic disorder and medical illness. Panic disorder either caused worsening of the medical illness or was associated with continued physiologic symptoms that mimicked the symptoms of the medical illness after the illness had improved. In both cases, panic disorder was associated with high rates of medical utilization, increased patient suffering, and often costly medical tests. Accurate diagnosis and treatment decreased physiologic and psychiatric symptoms as well as medical utilization.