Irregular breathing during sleep in patients with panic disorder.

OBJECTIVE: The authors examined the nocturnal breathing patterns of patients with panic disorder to determine whether these individuals had respiratory irregularities at a time when anxiety was not manifest. METHOD: Respiratory polysomnography was conducted on 14 medication-free patients with panic disorder and 14 healthy comparison subjects. Semiautomated indices of ventilatory variability were calculated for representative 3-minute, artifact-free sleep samples, and manually scored indices of irregular breathing were rated (blind to diagnosis) for the entire last 2 nights of sleep. RESULTS: Patients with panic disorder had evidence of abnormal sleep breathing as indicated by increased irregularity in tidal volume during REM and an increased rate of microapneas (i.e., brief [5-10-second] pauses in breathing). A subgroup of patients (including some with recent sleep panic attacks) had indices of subtle disorders in breathing during sleep that were above the 95th percentile for the comparison subjects. CONCLUSIONS: These findings extend the observations in the awake state that patients with panic disorder breathe more irregularly than healthy comparison subjects. The irregularities may be attributable to altered brainstem sensitivity to CO2 or to other as yet unexplained factors. A possible relationship between irregular nocturnal breathing and sleep panic attacks is discussed.

Exploratory factor analysis of the Pain Anxiety Symptoms Scale in patients with chronic pain complaints.

The Pain Anxiety Symptoms Scale (PASS) is a 40-item self-report measure that consists of four subscales measuring aspects of pain-related anxiety and avoidance. Despite its growing popularity, there have been few studies of its psychometric properties. The primary purpose of this study was to determine the factor structure of the PASS in a sample of 259 chronic pain patients. Principal component analysis with oblique (Oblimin) rotation provided partial support for the factorial validity of the PASS. Five factors were extracted: (1) catastrophic thoughts, (2) physiological anxiety symptoms, (3) escape/avoidance behaviours, (4) cognitive interference, and (5) coping strategies. The use of analgesic medication did not influence the factor solution. The factors were characterised by correlating them with pain-related measures, and with measures of mood state. Implications are considered for revising the PASS subscales to provide a more comprehensive and factorially valid assessment of pain-related fear and avoidance.

Panic attacks in the nonclinical population: an empirical approach to case identification.

Although self-reports of panic attacks are common among student populations, it is not clear that their panic experiences are actually comparable to those of patients with clinical anxiety disorders. An empirical approach was taken to this problem by using a cluster analysis procedure to identify subjects within two samples of university students who reported panic attack symptom profiles that resembled those of patients with panic disorder. Such empirically defined "clinical" panic attacks were reported by 7.0% and 8.1% of the two samples. This predominantly female group accounted for most of the increased psychopathology that has been reported in previous studies of nonclinical panic.

The continuity of depression symptoms: use of cluster analysis for profile identification in patient and student samples.

BACKGROUND: Findings from several sources suggest that depression lies on a continuum whereby mild and severe variants are thought to differ in severity (i.e., quantitatively), but not in kind (i.e., qualitatively). The current study used cluster analysis to extend this work to examination of depression symptom profiles obtained in distressed student 'analogue' samples and clinically depressed samples. METHOD: Patients with major depressive disorder (n = 101) provided seed points for the depressed cluster, and 176 non-distressed university students (Beck Depression Inventory score < or = 8) provided seed points for the non-depressed cluster. The symptom profiles of three levels of analogue depressed samples were then evaluated (BDI > or = 9, BDI > or = 16, and BDI > or = 21). RESULTS: Only 35.4% of BDI > or = 9 analogue respondents were empirically sorted to the depression cluster and the majority were assigned to the non-depressed cluster. The proportion assigned to the depression cluster increased to 70.5% and to 86.2% when higher BDI cutoffs of 16 and 21 were examined, respectively. The DSM-IV depression symptom profile of the BDI > or = 21 group was very similar to the profile defined by clinical patients. LIMITATIONS: The study relied solely on self-report to assess symptom severity. CONCLUSIONS: It is recommended that higher BDI cutoffs be utilized in analogue depression research than is currently common. On quantitative grounds, analogue subjects who were sorted to the clinically defined depression cluster seem to best represent the idea of depression continuity.

Discrepancies between self and observer ratings of depression. The relationship to demographic, clinical and personality variables.

BACKGROUND: The observer-rated Hamilton depression scale (HamD) and the self-report Beck Depression Inventory (BDI) are among the most commonly used rating scales for depression, and both have well demonstrated reliability and validity. However, many depressed subjects have discrepant scores on these two assessment methods. The present study evaluated the ability of demographic, clinical and personality factors to account for the discrepancies observed between BDI and HamD ratings. METHOD: The study group consisted of 94 SCID-diagnosed outpatients with a current major depressive disorder. Subjects were rated with the 21-item HamD and completed the BDI and the NEO-Five Factor Inventory. RESULTS: Younger age, higher educational attainment, and depressive subtype (atypical, non-melancholic) were predictive of higher BDI scores relative to HamD observer ratings. In addition, high neuroticism, low extraversion and low agreeableness were associated with higher endorsement of depressive symptoms on the BDI relative to the HamD. In general, these predictive variables showed a greater ability to explain discrepancies between self and observer ratings of psychological symptoms of depression compared to somatic symptoms of depression. LIMITATIONS: The study does not determine which aspects of neuroticism and extraversion contribute to the observed BDI/HamD discrepancies. CONCLUSIONS: Depression ratings obtained with the BDI and HamD are frequently discordant and a number of patient characteristics robustly predict the discrepancy between these two rating methods. The value of multi-modal assessment in the conduct of research on depressive disorders is re-affirmed.

Panic disorder and vestibular disturbance: an overview of empirical findings and clinical implications.

The purpose of this article is to provide a general overview of the growing literature on the relationship between panic disorder and vestibular disturbance. This relationship has been examined from two distinct perspectives, including: (a) the assessment of vestibular dysfunction in patients with panic disorder; and (b) the evaluation of panic symptomatology in patients with vestibular disturbance. Consequently, this review focuses primarily on the literature pertaining to vestibular symptoms in patients with panic disorder and panic symptomatology in patients with vestibular complaints. Subsequent to this review we discuss clinical implications suggested by the data, outline recommendations for treatment, and highlight some directions for future investigation.

Neurotic butterflies in my stomach: the role of anxiety, anxiety sensitivity and depression in functional gastrointestinal disorders.

This study examined the prevalence of functional gastrointestinal (FGI) disorders, and the association between FGI disorders and measures of affective distress, among a sample of 127 university students. Subjects completed a questionnaire battery including Research Diagnostic Questions for Functional Gastrointestinal Disorders, the Beck Anxiety Inventory, the Anxiety Sensitivity Index, the Beck Depression Inventory, and a medical utilization questionnaire. FGI disorders were diagnosed in 51.2% of the sample. Functional dyspepsia (22.8%), dyschezia (20.5%), functional heartburn (19.7%), functional chest pain (18.1%), and globus (12.6%) were the most frequently diagnosed disorders. Participants experiencing globus, functional dyspepsia, or functional heartburn showed significant differences in terms of anxiety, anxiety sensitivity, depression, and/or physician visits, when compared with participants without these disorders. Our results suggest that FGI disorders are strikingly prevalent among young adults, and specific FGI disorders are associated with affective distress. Implications of the observed association between psychological factors and FGI disorders are discussed.

Posttraumatic stress disorder and work-related injury.

The literature indicates a substantial overlap between chronic pain and posttraumatic stress disorder (PTSD) symptoms in individuals who sustain accidental injury. To date, however, there have been no studies of PTSD symptoms in individuals who experience work-related injury. Consequently, we assessed 139 consecutive injured workers using the Modified PTSD Symptom Scale (Falsetti, Resnick, & Kirkpatrick, 1993), as well as a number of general measures of psychopathology. Most participants reported chronic pain and all were receiving workers compensation. Results indicated that 34.7% and 18.2% of the sample reported symptoms consistent with PTSD and partial PTSD, respectively. When PTSD symptom frequency and severity were considered criterion variables in multiple regression analyses, depression was found to be significantly associated with the former and anxiety sensitivity, social fears, and somatic focus with the later. Finally, these measures of general psychopathology correctly classified 78.6% of individuals with PTSD and 81.3% of those with no PTSD. These results suggest that a considerable proportion of injured workers display symptoms consistent with PTSD and that these symptoms are related to general negative affect. Implications, including the suggestion of clinical intake screening of PTSD in this population, are discussed.

Perceptions of parental bonding and symptom severity in adults with depression: mediation by personality dimensions.

OBJECTIVE: An association between anomalous parental bonding experiences (lack of parental care, overprotection, or both) and depression during adulthood has been observed in several studies. The objective of the present study was to evaluate several different personality dimensions as possible mediators of the relationship between perceptions of parental bonding and depressive symptoms in adulthood. METHODS: Outpatients with depression (n = 138) completed the Parental Bonding Instrument (PBI), the Beck Depression Inventory (BDI), and several measures of proposed personality vulnerabilities to depression. The conceptual and methodological criteria of Baron and Kenny (1986) were used to assess possible mediating effects of personality variables. RESULTS: In men, overprotection by their fathers was significantly associated with depression; neuroticism, socially prescribed perfectionism, and concern over mistakes acted as mediators of this relationship. In women, lack of care by their mothers was significantly associated with depression; self-criticism, socially prescribed perfectionism, and concern over mistakes mediated this relationship. CONCLUSIONS: The present study provides evidence that personality factors may mediate the observed relationship between parental rearing style and depression. These potential causal mechanisms warrant longitudinal evaluation.

Effect of a novel environment on resting heart rate in panic disorder.

Several studies have found higher resting heart rate among patients with panic disorder compared to healthy controls, whereas others have found no differences. It has been suggested that these differences may result from anticipatory anxiety. The purpose of this study was to compare the resting heart rates of 10 patients with panic disorder, 11 patients with social phobia, and 13 healthy controls during two consecutive visits to our laboratory. There were no significant differences between groups on resting heart rate on either day. However, patients with panic disorder did have significantly higher resting heart rates on day 1 versus day 2. This suggests that patients with panic disorder may experience greater anticipatory anxiety which is manifested in a higher resting heart rate than patients with social phobia or healthy controls. Implications for previous and future reports on resting heart rate measures in patients with panic disorder are discussed.

Neurocognitive function in panic disorder and social phobia patients.

A neuropsychological test battery designed to assess verbal learning and memory, visual memory, psychomotor speed, cognitive flexibility and concentration was administered to patients with panic disorder (N = 18) and social phobia (N = 18) and a group of healthy control subjects (N = 16). Overall, the neurocognitive performance of the panic disorder and social phobia patients was lower than that of control subjects. Analyses of the verbal test variables indicated reduced performance in panic disorder and social phobia patients, relative to control subjects, on measures of verbal learning and memory. In addition, panic disorder patients exhibited deficits on short-delay free recall. No group differences were observed on tests of visual memory, psychomotor speed, cognitive flexibility, and concentration. These results, while indicative of diminished neuropsychological test performance in patients with panic disorder and social phobia, do not suggest the presence of syndrome-specific or localized neurocognitive deficits.