Psychopharmacotherapy of panic disorder: 8-week randomized trial with clonazepam and paroxetine

The objective of the present randomized, open-label, naturalistic 8-week study was to compare the efficacy and safety of treatment with clonazepam (N = 63) and paroxetine (N = 57) in patients with panic disorder with or without agoraphobia. Efficacy assessment included number of panic attacks and clinician ratings of the global severity of panic disorders with the clinical global impression (CGI) improvement (CGI-I) and CGI severity (CGI-S) scales. Most patients were females (69.8 and 68.4% in the clonazepam and paroxetine groups, respectively) and age (mean ± SD) was 35.9 ± 9.6 years for the clonazepam group and 33.7 ± 8.8 years for the paroxetine group. Treatment with clonazepam versus paroxetine resulted in fewer weekly panic attacks at week 4 (0.1 vs 0.5, respectively; P < 0.01), and greater clinical improvements at week 8 (CGI-I: 1.6 vs 2.9; P = 0.04). Anxiety severity was significantly reduced with clonazepam versus paroxetine at weeks 1 and 2, with no difference in panic disorder severity. Patients treated with clonazepam had fewer adverse events than patients treated with paroxetine (73 vs 95%; P = 0.001). The most common adverse events were drowsiness/fatigue (57%), memory/concentration difficulties (24%), and sexual dysfunction (11%) in the clonazepam group and drowsiness/fatigue (81%), sexual dysfunction (70%), and nausea/vomiting (61%) in the paroxetine group. This naturalistic study confirms the efficacy and tolerability of clonazepam and paroxetine in the acute treatment of patients with panic disorder.

Psychopharmacotherapy of panic disorder: 8-week randomized trial with clonazepam and paroxetine

The objective of the present randomized, open-label, naturalistic 8-week study was to compare the efficacy and safety of treatment with clonazepam (N = 63) and paroxetine (N = 57) in patients with panic disorder with or without agoraphobia. Efficacy assessment included number of panic attacks and clinician ratings of the global severity of panic disorders with the clinical global impression (CGI) improvement (CGI-I) and CGI severity (CGI-S) scales. Most patients were females (69.8 and 68.4% in the clonazepam and paroxetine groups, respectively) and age (mean ± SD) was 35.9 ± 9.6 years for the clonazepam group and 33.7 ± 8.8 years for the paroxetine group. Treatment with clonazepam versus paroxetine resulted in fewer weekly panic attacks at week 4 (0.1 vs 0.5, respectively; P < 0.01), and greater clinical improvements at week 8 (CGI-I: 1.6 vs 2.9; P = 0.04). Anxiety severity was significantly reduced with clonazepam versus paroxetine at weeks 1 and 2, with no difference in panic disorder severity. Patients treated with clonazepam had fewer adverse events than patients treated with paroxetine (73 vs 95%; P = 0.001). The most common adverse events were drowsiness/fatigue (57%), memory/concentration difficulties (24%), and sexual dysfunction (11%) in the clonazepam group and drowsiness/fatigue (81%), sexual dysfunction (70%), and nausea/vomiting (61%) in the paroxetine group. This naturalistic study confirms the efficacy and tolerability of clonazepam and paroxetine in the acute treatment of patients with panic disorder.

Panic disorder and social anxiety disorder subtypes in a caffeine challenge test

Studies have demonstrated the vulnerability of anxiety disorder patients to challenge tests. Our aim was to observe if panic disorder (PD) patients and generalized social anxiety disorder (GSAD) and performance social anxiety disorder (PSAD) patients respond in a similar way to the induction of anxiety symptoms and panic attacks by an oral caffeine challenge test. We compared 28 PD patients, 25 GSAD patients, 19 PSAD, and 26 control subjects after a 480-mg caffeine test. The patients had not received psychotropic drugs for at least a 4-week period. In a randomized double-blind experiment performed in two occasions 7 days apart, 480 mg of caffeine and a caffeine-free solution were administered and anxiety scales were administered before and after each test. A panic attack was induced in 17 (60.7%) PD patients, 4 (16.0%) GSAD patients, and 10 (52.6%) PSAD patients, during the caffeine test. None of the control subjects had a panic attack after the caffeine intake. Neither patients nor any control subject had a panic attack after drinking the caffeine-free solution. Our data suggest that there is an association between PD and PSAD hyperreactivity to an oral caffeine challenge test. The PD and PSAD patients had a higher number of induced panic attacks, some specific anxiety symptoms, and a more severe anxiety response than GSAD patients and normal volunteers.

A caffeine challenge test in panic disorder patients, their healthy first-degree relatives, and healthy controls

Our aim was to observe the induction of anxiety symptoms and panic attacks by a caffeine challenge test in panic disorder (PD) patients (DSM-IV) and their healthy first-degree relatives. We randomly selected 25 PD patients, 27 healthy first-degree relatives of probands with PD, and 22 healthy volunteers with no family history of PD. In a randomized double-blind experiment performed over two occasions 7 days apart, 480 mg caffeine and a caffeine-free solution were administered in a coffee form. Using specific panic attack criteria, 52.0% (n=13) PD patients, 40.7% (n=11) first-degree relatives (chi2=1.81, df=1, P=0.179), and none of the control subjects had a panic attack after the test (chi2=51.7, df=2, P<0.001). In this caffeine challenge test, PD patients and their first-degree relatives were more sensitive than healthy volunteers to the panic attack symptoms but less sensitive to headache, increase in blood pressure, and insomnia. Our data suggest that there is an association between panic attacks after the intake of 480 mg of caffeine in PD patients and their first-degree relatives. There is a clear differentiation of PD patients and their first-degree relatives by a caffeine test from the healthy group.

Demographic and clinical features of panic disorder comorbid with bipolar I disorder: a 3-year retrospective study

BACKGROUND

Mood disorders are considered related to anxiety disorders and their association may determine clinical course and prognosis. We aimed to describe with retrospective methodology the demographic, clinical, and treatment features in a group of panic disorder comorbid with bipolar I disorder (PD-BI) patients who were been treated for at least 3 year-period and compare them with bipolar I (BI) patients who were treated during the same period.

METHOD

We compared the demographic and clinical data of 26 PD-BI, 28 BI, and 25 panic disorder (PD) outpatients without history of comorbidity with mood disorder were diagnosed and treated for at least 3 years in the Federal University of Rio de Janeiro.

RESULTS

PD group have a higher educational level, are more married, and are more economically active. In the PD-BI and BI patients the disorders started earlier. They also turn out to have an equivalent pattern in the presence of drug abuse episodes, moderate or severe depressive episodes, psychotic episodes, suicide attempts, maniac episodes, mixed episodes, use of fewer days of antidepressants and benzodiazepines, and use of more days of antipsychotics and mood stabilizers. The PD-BI and the BI groups had a higher frequency of depressive episodes and psychotic episodes.

LIMITATIONS

It is a retrospective data description based on a naturalistic treatment. The sample has a small size and the some data could be different in a large sample.

CONCLUSION

PD-BI patients have demographic, clinical and therapeutic features similar to BI and the data support its validation as a special severe bipolar I disorder subgroup.

Panic disorder respiratory subtype: a comparison between responses to hyperventilation and CO2 challenge tests

In this study 117 panic disorder patients were divided into a respiratory subtype group and a non-respiratory subtype group. The respiratory subtype patients were observed to be more sensitive to the 35% CO(2) inhalation challenge test and the hyperventilation test than the non-respiratory subtype patients.

Clinical features of respiratory and nocturnal panic disorder subtypes

Our aim is to compare the panic disorder (PD) respiratory subtype and the nocturnal panic subtype. A group of 193 PD patients (DSM-IV) was examined in the Laboratory of Panic and Respiration in the Institute of Psychiatry of the Federal University of Rio de Janeiro. The diagnoses were made using the SCID-I for DSM-IV. The subtypes were the respiratory (with 4 out of 5 prominent respiratory symptoms during the panic attacks [PA]) vs. non-respiratory, likewise PD with nocturnal (during sleep) PAs vs. PD with only diurnal PAs. The respiratory subtype accounted for 56.5% (n=109) of our sample; the non-respiratory subtype, 43.5% (n=84); the nocturnal subtype, 49.2% (n=95); and the non-nocturnal subtype, 50.8% (n=98). Despite a rich literature concerning correlations between the respiratory system and nocturnal panic attacks, our data do not support these findings, as the comparison of proportions in the respiratory and nocturnal groups did not differ. The non-nocturnal subtype was significantly associated with agoraphobia, and the respiratory subtype was not associated with these variables.

Caffeine and 35% carbon dioxide challenge tests in panic disorder

Our aim was to compare the demographic and clinical features of panic disorder (PD) patients with agoraphobia-DSM-IV-who had a panic attack after both an oral caffeine and the 35% carbon dioxide (CO2) challenge tests (responsive group) and compare them with PD patients who did not have a panic attack after both tests (non-responsive group). We examined 83 PD patients submitted to a 35% CO2 test and to an oral caffeine (480 mg) intake within 1 week interval. A panic attack was induced in 51 (61.4%) patients during the CO2 test (chi2=31.67, df=1, p<0.001) and in 38 (45.8%) patients during the caffeine test (chi2=18.28, df=1, p=0.023). All patients who had a panic attack during the caffeine test also had a panic attack during the CO2 test (n=38)-responsive group. The responsive had more (chi2=24.55, df=1, p=0.008) respiratory PD subtype, disorder started earlier (Mann-Whitney, p<0.001) had a higher familial prevalence of PD (chi2=20.34, df=1, p=0.019), less previous alcohol abuse (chi2=23.42, df=1, p<0.001), and had more previous depressive episodes (chi2=27.35, df=1, p<0.001). Our data suggest that there is an association between respiratory PD subtype and hyperreactivity to challenge tests: CO2 and oral caffeine.

Caffeine challenge test in panic disorder and depression with panic attacks

Our aim was to observe if patients with panic disorder (PD) and patients with major depression with panic attacks (MDP) (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria) respond in a similar way to the induction of panic attacks by an oral caffeine challenge test. We randomly selected 29 patients with PD, 27 with MDP, 25 with major depression without panic attacks (MD), and 28 healthy volunteers. The patients had no psychotropic drug for at least a 4-week period. In a randomized double-blind experiment performed in 2 occasions 7 days apart, 480 mg caffeine and a caffeine-free (placebo) solution were administered in a coffee form and anxiety scales were applied before and after each test. A total of 58.6% (n = 17) of patients with PD, 44.4% (n = 12) of patients with MDP, 12.0% (n = 3) of patients with MD, and 7.1% (n= 2) of control subjects had a panic attack after the 480-mg caffeine challenge test (chi(2)(3) = 16.22, P = .001). The patients with PD and MDP were more sensitive to caffeine than were patients with MD and healthy volunteers. No panic attack was observed after the caffeine-free solution intake. The patients with MD had a lower heart rate response to the test than all the other groups (2-way analysis of variance, group by time interaction with Greenhouse-Geisser correction: F(3,762) = 2.85, P = .026). Our data suggest that there is an association between panic attacks, no matter if associated with PD or MDP, and hyperreactivity to an oral caffeine challenge test.

Personality traits spectrum in panic disorder and major depression

OBJECTIVE

Our aim was to identify the personality traits in patients with panics disorder, major depression and with both disorders (comorbidity).

METHOD

Diagnoses were made with the Structured Clinical Interview for DSM-IV before the treatment, and the personality evaluation with the Maudsley Personality Inventory was made during the follow-up. Four groups were analyzed: a control group (n = 30), a major depression without panic disorder group (n = 45); a panic disorder without major depression group (n = 56) and a comorbidity group (n = 21), with major depression and panic disorder, simultaneously.

RESULTS

All disorder groups had significantly higher neuroticism means when compared to the control group. The highest mean was in the comorbidity group, followed by the major depression group and the panic disorder group. The difference of neuroticism means between the comorbidity group and the panic disorder group also reached statistical significance. The lowest extraversion mean was in the comorbidity group, followed by the major depression group, the panic disorder group, and the control group. Compared to normal controls, extraversion was significantly low in the comorbidity and major depression groups.

CONCLUSION

In our sample, there was a continuum of personality traits between panic disorder and major depression and, the co-occurrence of these disorders was associated with accentuated personality traits.

35% Carbon dioxide and breath-holding challenge tests in panic disorder: a comparison with spontaneous panic attacks

Respiration and its control mechanisms may represent an important system involved in abnormal anxiety. Our aim was to compare the demographic and clinical features of patients with panic disorder (PD) with agoraphobia (DSM-IV) who had a panic attack after both the 35% carbon dioxide (CO(2)) test and the breath-holding test (CPA group), and compare them with PD patients who did not have a panic attack after both tests (NPA group). We examined 76 patients with PD who were administered a 35% CO(2)test and a breath-holding test within a 1-week interval. Anxiety scales were applied before and after each test. A panic attack was induced in 50 (65.8%) patients during the CO(2)test (chi(2) = 28.44, df = 1, P<.001) and in 40 (52.6%) patients during the breath-holding test (chi(2) = 15.35, df = 1, P = .036). All patients who had a panic attack during the breath-holding test also had a panic attack during the CO(2)test (n = 40; CPA group). Twenty-six (34.2%) patients with PD did not have a panic attack after both respiratory tests (NPA group). The CPA group had more (chi(2) = 21.67, df = 1, P = .011) respiratory PD subtype. In the CPA group, the disorder started earlier (Mann-Whitney, P<.001), had a higher familial prevalence of PD (chi(2) = 18.34, df = 1, P = .028), and had more previous depressive episodes (chi(2) = 23.59, df = 1, P<.001). Our data suggest that there is an association between respiratory PD subtype and the response to respiratory challenge tests: CO(2)and breath-holding. The CPA may be confirmed as a subgroup of respiratory PD subtype.

Comparison between hyperventilation and breath-holding in panic disorder: patients responsive and non-responsive to both tests

Our aim was to compare the demographic and psychopathological features of panic disorder (PD) patients who underwent hyperventilation and breath-holding challenge tests, and to describe the features of patients who had a panic attack after both tests versus those patients who did not experience panic after either test. Eighty-five PD patients were induced to hyperventilate (30 breaths/min) for 4 min, and a week later to hold their breath for as long as possible four times with a 2-min interval in between. Anxiety scales were applied before and after the tests. Patients who responded with a panic attack to both tests (BPA, n = 25) were compared with patients who experienced spontaneous panic attacks but did not panic in response to the two tests (NPA, n = 16). The BPA group had a significantly higher presence of respiratory symptoms during a panic attack. The criteria for the respiratory PD subtype were fulfilled in 18 (72.0%) BPA patients and in 6 (37.5%) NPA patients. The BPA patients had a later onset of panic disorder and a higher familial prevalence of PD. Our data suggest that there is a distinction between PD patients who were sensitive to both hyperventilation and breath-holding tests and PD patients who were not affected by the challenge tests. The panic attack may be a final common pathway for different types of stimuli, and respiratory tests may characterize different PD subgroups.

Psychopathological profile of 35% CO2 challenge test-induced panic attacks: a comparison with spontaneous panic attacks

Our aim was to describe the clinical features of 35% CO2-induced panic attacks in patients with panic disorder (PD) (Diagnostic and Statistical Manual and Mental Disorders, Fourth Edition) and compare them with the last spontaneous panic attack in patients with PD who had not had a panic attack after the 35% CO2 challenge test. We examined 91 patients with PD submitted to the CO2 challenge test. The test consisted of exhaling as fully as possible, took a fast vital capacity breath, held their breath for 8 seconds, exhaled, and then repeated the fast vital capacity breath, again holding for 8 seconds. The patients inhaled the 35% CO2/65% O2 mixture or atmospheric compressed air, randomly selected in a double-blind design. Scales were applied before and after the test. A total of 68.1% (n = 62) patients with PD had a panic attack (responders) after the CO2 test (chi2(1) = 25.87, P = .031). The last spontaneous panic attack and the symptom profile from the patients with PD who had not had a panic attack after the test (n = 29, 31.9%) were described to compare. The responders had more respiratory symptoms (chi2(1) = 19.21, P < .001), fulfilling the criteria for respiratory PD subtype (80.6%); the disorder started earlier (Mann-Whitney, P < .001), had a higher familial prevalence of PD (chi2(1) = 20.45, P = .028), and had more previous depressive episodes (chi2(1) = 27.98, P < .001). Our data suggest that there is an association between respiratory PD subtype and hyperreactivity to a CO2 respiratory challenge test. The responders may be a subgroup of respiratory PD subtype with future diagnostic and therapeutic implications.

Demographic and clinical features of schizoaffective (schizobipolar) disorder--a 5-year retrospective study. Support for a bipolar spectrum disorder

BACKGROUND

Schizobipolar disorder is considered related to both schizophrenia and bipolar disorder. We aimed to describe with retrospective methodology the demographic, clinical, and treatment features in a group of schizobipolar disorder patients who have been treated for at least a 5-year period and compare them with bipolar I and schizophrenic patients who were treated during the same period.

METHOD

We compared the demographic and clinical data of 61 schizobipolar, 57 bipolar I, and 55 schizophrenic outpatients who were diagnosed and treated for at least 5 years in the outpatient clinic in the Federal University of Rio de Janeiro.

RESULTS

The schizobipolar disorder patients had a profile similar to the bipolar I patients but are significantly different from schizophrenic patients in educational level, marital status, occupation, drug and alcohol abuse episodes, presence of depressive, mixed and maniac episodes, family history of bipolar I and mood disorders, and use of medications. Only the age of onset, suicide attempts, and family history of suicide are not significantly different among the groups. The schizophrenic patients used antipsychotics for more days and the schizobipolar and bipolar I used more antidepressants and mood stabilizers. 37 (60.6%) schizobipolar patients had their diagnosis changed to bipolar disorder by their physician in different periods during the period studied.

LIMITATIONS

It is a retrospective data description based on a naturalistic treatment. The family history was collected from the patient and whenever possible from one first-degree relative.

CONCLUSION

Schizobipolar disorder patients have demographic, clinical and therapeutic features similar to bipolar I patients and data support its definite inclusion in the bipolar spectrum group.

A three-year follow-up study of patients with the respiratory subtype of panic disorder after treatment with clonazepam

The demographic, clinical and therapeutic features of the respiratory subtype of panic disorder (PD) versus the non-respiratory subtype were studied in a prospective design. Sixty-seven PD outpatients (DSM-IV), who had previously been categorized into respiratory (n=35) and non-respiratory (n=32) subgroups, were openly treated with clonazepam for a 3-year period. The principal measure of efficacy was the number of panic attacks, obtained from the Sheehan Panic and Anticipatory Anxiety Scale. In the first 8 weeks of treatment (acute phase), the respiratory subtype group had a significantly faster response to clonazepam. During the follow-up (weeks 12-156), the two subgroups did not differ significantly in the number of panic attacks experienced from baseline to end point. Patients in the respiratory subtype were characterized by a later onset of disorder and a family history of PD. Patients in the non-respiratory subgroup had a significantly higher number of past depressive episodes than those in the respiratory subgroup. The respiratory subgroup had a faster response after 8 weeks of treatment and an equivalent response in the 3-year follow-up period. Clonazepam had a sustained therapeutic effect over the entire treatment period.

Diurnal panic attacks with and without nocturnal panic attacks: are there some phenomenological differences?

OBJECTIVE: To compare nocturnal and diurnal panic attacks in a cross-sectional study and in a longitudinal prospective short-term follow-up. METHODS: We selected 57 panic disorder (PD) subjects (DSM-IV) and rated them with the Panic Disorder Severity Scale (PDSS) at baseline and after 30 days of treatment with nortriptyline, and with the Eysenck Personality Inventory and the Brown Attention Deficit Disorder (ADD) Scale at baseline. RESULTS: The sample was divided into a nocturnal and diurnal panic attack (NDPA) group - 57.9% (n = 33) - and a diurnal panic attack (DPA) group - 42.1% (n = 24). The groups showed a similar mean age at onset of PD and a pattern of prominent respiratory symptoms. The PDSS did not differ between the groups following short-term treatment (p = 0.451). There were also neither significant differences in Neuroticism (p = 0.094) and Extroversion (p = 0.269) nor in the Brown ADD Scale (p = 0.527). CONCLUSION: In our study, patients with both nocturnal and diurnal panic attacks showed similar features in their phenomenology and short-term outcome when compared to pure diurnal panic attacks patients.

Do social anxiety disorder patients belong to a bipolar spectrum subgroup?

BACKGROUND

It has been proposed that all forms of bipolar disorder-perhaps all primary affective disorders-are best conceptualized as a spectrum of related illness, clinically overlapping but not necessarily genetically uniform illnesses. We aim to describe with retrospective methodology the demographic, clinical, and therapeutic response in a group of social anxiety disorder (SA) patients who improves while taking antidepressants and compare them with bipolar II (B-II) patients.

METHODS

57 SA outpatients (DSM-IV) were diagnosed and naturalistic efficacious treated with selective serotonin reuptake inhibitors (SSRI). Their demographic, clinical features and therapeutic response were compared with 41 DSM-IV bipolar II patients in their starting evaluations in our outpatient clinic in the Federal University of Rio de Janeiro, Brazil.

RESULTS

There is a sub-group of SA patients who improves while taking antidepressants and presents a clear hypomanic phase. Their improvement is identical to a mild/moderate hypomanic state. Without the antidepressant, the symptoms of SA return. The SA and B-II patients have a similar number of previous depressive episodes, alcohol abuse, suicide attempts, and family history for mood disorder.

LIMITATIONS

It is a retrospective data description based on a naturalist follow-up.

CONCLUSION

Some SA patients have demographic, clinical and therapeutic features similar to B-II patients and they might just be a Bipolar-III sub-group with a higher level of complains to social situations and without spontaneous hypomania during lifetime.

Clonidine in respiratory panic disorder subtype

OBJECTIVE

Clonidine, which inhibits locus coeruleus discharge, would seem for theoretical reasons to be a good antipanic drug. Panic disorder (PD) presents a heterogeneous cluster of symptoms and a classification based on subtypes has been suggested and the respiratory symptoms group appears as a distinct subtype.

METHOD

We report three cases of respiratory PD patients who were successfully treated with clonidine.

RESULTS

Patients obtained panic free status, reduced anxiety levels and better functioning after clonidine administration (0.30-0.45 mg/day) for 6 weeks.

CONCLUSION

Clonidine can be effective in the treatment of respiratory PD. This drug might play a role in relieving symptoms of anxiety due to noradrenergic hyperactivity in these patients.

Clinical features of panic patients sensitive to hyperventilation or breath-holding methods for inducing panic attacks

Our aim was to compare the clinical features of panic disorder (PD) patients sensitive to hyperventilation or breath-holding methods of inducing panic attacks. Eighty-five PD patients were submitted to both a hyperventilation challenge test and a breath-holding test. They were asked to hyperventilate (30 breaths/min) for 4 min and a week later to hold their breath for as long as possible, four times with a 2-min interval. Anxiety scales were applied before and after the tests. We selected the patients who responded with a panic attack to just one of the tests, i.e., those who had a panic attack after hyperventilating (HPA, N = 24, 16 females, 8 males, mean age +/- SD = 38.5 +/- 12.7 years) and those who had a panic attack after breath holding (BHPA, N = 20, 11 females, 9 males, mean age +/- SD = 42.1 +/- 10.6 years). Both groups had similar (chi(2) = 1.28, d.f. = 1, P = 0.672) respiratory symptoms (fear of dying, chest/pain discomfort, shortness of breath, paresthesias, and feelings of choking) during a panic attack. The criteria of Briggs et al. [British Journal of Psychiatry, 1993; 163: 201-209] for respiratory PD subtype were fulfilled by 18 (75.0%) HPA patients and by 14 (70.0%) BHPA patients. The HPA group had a later onset of the disease compared to BHPA patients (37.9 +/- 11.0 vs 21.3 +/- 12.9 years old, Mann-Whitney, P < 0.001), and had a higher family prevalence of PD (70.8 vs 25.0%, chi(2) = 19.65, d.f. = 1, P = 0.041). Our data suggest that these two groups--HPA and BHPA patients--may be specific subtypes of PD.

Psychopathological description of hyperventilation-induced panic attacks: a comparison with spontaneous panic attacks

Our aim was to describe the clinical features of hyperventilation-induced panic attacks (HPA) in panic disorder patients - DSM-IV - and to compare them with their spontaneous panic attacks and with spontaneous panic attacks in panic disorder (PD) patients not sensible to the hyperventilation challenge test. We reexamined 88 previously studied PD patients when they were submitted to a hyperventilation challenge test. They were induced to hyperventilate (30 breaths/min) for 4 min and anxiety scales were applied before and after the test. A total of 51.1% (n = 45) PD patients had a panic attack after hyperventilating - HPA (chi(2) = 13.11, d.f. = 1, p = 0.017). The clinical symptoms of the most severe panic attack were recorded by the HPA patient and by the PD patients not sensible to this test (non-HPA; n = 43, 48.9%) in a diary during a 1-week period and then compared. The HPA group had more respiratory symptoms (chi(2) = 15.26, d.f. = 1, p < 0.001), fulfilling the criteria for the respiratory PD subtype (75.6%), the disorder started later (Mann-Whitney, p < 0.001), had a higher familial prevalence of PD (chi(2) = 19.45, d.f. = 1, p = 0.036), and had more previous depressive episodes (chi(2) = 18.74, d.f. = 1, p < 0.001). The HPA group had similar symptomatology in spontaneous attacks and HPA. The HPA group may be regarded as a subgroup of the respiratory panic disorder subtype with diagnostic and therapeutic implications.

Respiratory panic disorder subtype: acute and long-term response to nortriptyline, a noradrenergic tricyclic antidepressant

The goal of the study was to describe with prospective methodology the therapeutic response to nortriptyline in the respiratory panic disorder (PD) subtype versus the non-respiratory subtype. A total of 118 PD outpatients (DSM-IV) were previously divided into respiratory (n=77) and non-respiratory (n=41) subtypes and then treated with nortriptyline for 1 year. Demographic and clinical features were compared in the two groups. Anxiety scales were administered before and during the treatment by raters who were blind to the subtype diagnosis. The principal instruments used to evaluate response were the Clinical Global Impression, the Sheehan Panic and Anticipatory Anxiety Scale, and the Panic Disorder Severity Scale. In the first 8 weeks of treatment (acute phase), the respiratory subtype had a significantly faster response on all the major scales. At the end of the study (week 52), there was no difference in the scale scores, and the reduction in panic attacks from baseline to end-point did not differ significantly between the two groups. In the respiratory subtype, the disorder had a later onset, was associated with a high familial history of mental disorder, and significantly more often required treatment with more than an occasional benzodiazepine. The non-respiratory subtype had significantly more previous depressive episodes. In conclusion, the respiratory PD subtype had a faster response to treatment with nortriptyline at 8 weeks than did the non-respiratory subtype, and an equivalent response after 1 year of treatment.

Panic disorder in a breath-holding challenge test: a simple tool for a better diagnosis

OBJECTIVE: Our aim was to observe if anxiety disorder patients - DSM-IV - respond in a similar way to the induction of panic attacks by a breath-holding challenge test. METHOD: We randomly selected 29 panic disorder (PD) patients, 27 social anxiety disorder (SAD) patients, 21 generalized anxiety disorder (GAD) patients. They were induced to breath-hold for as long as possible four times with two-minute interval between them. Anxiety scales were applied before and after the test. RESULTS: A total of 44.8% (n=13) PD patients, 14.8% (n=4) SAD patients, 9.5% (n=2) GAD patients had a panic attack after the test (c²= 21.44, df= 2, p=0.001). There was no heart rate or anxiety levels difference among the groups before and after the test. CONCLUSION: In this breath-holding challenge test the panic disorder patients were more sensitive than other anxiety disorder patients.

Early carbon dioxide challenge test may predict clinical response in panic disorder

We examined whether responses to the carbon dioxide (CO(2)) challenge test were correlated with clinical response. Thirty-four panic disorder patients participated in a CO(2) test after 1 h, 2 weeks and 6 weeks of treatment with clonazepam (2 mg/day) or placebo. The clonazepam group had significantly fewer panic attacks in response to the CO(2) test and the test may predict clinical response.

A breath-holding challenge in panic disorder patients, their healthy first-degree relatives, and normal controls

Our aim was to observe the induction of panic attacks (PA) symptoms by a breath-hold test in panic disorder (PD) patients as the Diagnostic and Statistical Manual for Mental Disorders 4th edition (DSM-IV) and their healthy first-degree relatives. We randomly selected 26 PD patients, 28 healthy first-degree relatives of probands with PD and 25 normal volunteers with no family history of PD. They were induced to breath-hold for as long as possible four times with a two-min interval between them. Anxiety scales were applied before and after the test. Using specific PA criteria, 46.1% (n=12) PD patients, 7.1% (n=2) first-degree relatives and 4.0% (n=1) control subjects had a PA after the test (chi(2)=7.82, df=2, P=0.023). There was no heart rate, anxiety levels or breath-hold time differences among the groups. In this breath hold challenge test PD patients were more sensitive to breath-hold than first-degree relatives and normal volunteers.

Smoking and psychiatric disorders: a comorbidity survey

Epidemiological and clinical studies have shown a positive correlation between smoking and psychiatric disorders. To investigate the prevalence of cigarette smoking, 277 psychiatric outpatients with anxiety or depressive disorders (DSM-IV) answered a self-evaluation questionnaire about smoking behavior and were compared with a group of 68 control subjects. The diagnoses (N = 262) were: 30.2% (N = 79) major depressive disorder, 23.3% (N = 61) panic disorder, 15.6% (N = 41) social anxiety disorder, 7.3% (N = 19) other anxiety disorders, and 23.7% (N = 62) comorbidity disorders. Among them, 26.3% (N = 69) were smokers, 23.7% (N = 62) were former smokers and 50.0% (N = 131) were nonsmokers. The prevalence of nicotine dependence among the smokers was 59.0% (DSM-IV). The frequency of cigarette smoking did not show any significant difference among the five classes of diagnosis. The social anxiety disorder patients were the heaviest smokers (75.0%), with more unsuccessful attempts to stop smoking (89.0%). The frequency of former smokers was significantly higher among older subjects and nonsmokers were significantly younger (chi2 = 9.13, d.f. = 2, P = 0.01). Our data present some clinical implications suggesting that in our psychiatric outpatient sample with anxiety disorder, major depression and comorbidity (anxiety disorder and major depression), the frequency of cigarette smoking did not differ from the frequency found in the control group or in general population studies. Some specific features of our population (outpatients, anxiety and depressive disorders) might be responsible for these results.

Psychiatric disorders in asthmatic outpatients

It has been reported that the lifetime prevalence of panic disorder in patients with pulmonary disease is higher than epidemiologic estimates of population prevalence. We evaluated the frequency of anxiety disorders in 86 subjects from the Outpatient Asthma Clinic. Psychiatric diagnoses were assessed with the Mini-International Neuropsychiatric Interview 4.4 Version (MINI). Forty-five asthmatic patients (52.3%) reported at least one current anxiety disorder. The frequency of panic disorder with or without agoraphobia was 13.9% (n=12) and that of agoraphobia without panic disorder was 26.8% (n=23). Social anxiety and generalized anxiety disorders occurred in 9.3% (n=8) and 24.4% (n=21) of the sample, respectively. Twenty-nine patients (33.7%) reported a major depressive episode. The psychiatric morbidity of the sample was 61.6% (n=53). Our results tend to support the high morbidity of anxiety disorders, particularly panic/agoraphobic spectrum disorders, in asthmatic outpatients.

Transtorno de pânico e tabagismo

A relação entre transtorno de pânico e tabagismo é tema de interesse clínico. A associação entre transtorno de pânico e tabagismo foi revisada pelo sistema Medline (1980 a 2001), utilizando as seguintes palavras-chave: "tabagismo", "tabaco", "transtorno de pânico", "transtornos de ansiedade". As referências dos artigos encontrados também foram consultadas. Em dois casos clínicos atendidos no Laboratório de Pânico e Respiração da Universidade Federal do Rio de Janeiro, Brasil, foi encontrada uma relação positiva entre tabagismo e transtorno de pânico. Em ambos os casos, houve melhora dos sintomas de ansiedade, ataque de pânico e abstinência de nicotina após tratamento farmacológico do transtorno de pânico. Estudos podem esclarecer a existência de possíveis mecanismos etiopatogênicos comuns entre tabagismo e transtorno de pânico, bem como responder a questões terapêuticas específicas.

Hyperventilation in panic disorder and social phobia

The aim of our study was to observe the induction of panic attacks by hyperventilation in a group of panic disorder and social phobia patients (DSM-IV). We randomly selected 26 panic disorder patients, 22 social phobics and 25 normal volunteers. They were drug-free for 1 week. Hyperventilation (30 breaths/min) was induced for 3 min. Anxiety scales were taken before and after the test. 61.5% (n = 16) of panic disorder patients, 22.7% (n = 5) of social phobics and 4.0% (n = 1) of control subjects had a panic attack after hyperventilating (p < 0.01, panic disorder vs. control; p < 0.05, panic disorder vs. social phobia; p = n.s., social phobia vs. control). Both anxiety disorder groups were more sensitive to hyperventilation than normal volunteers. The induction of panic attacks by voluntary hyperventilation may be an easy and useful test for validating the diagnosis in some specific panic disorder patients.

Double-blind clonazepam vs placebo in panic disorder treatment

OBJECTIVE

To assess the effectiveness of clonazepam, in a fixed dose (2 mg/day), compared with placebo in the treatment of panic disorder patients.

METHOD

24 panic disorder patients with agoraphobia were randomly selected. The diagnosis was obtained using the structured clinical interview for DSM-IV. All twenty-four subjects were randomly assigned to either treatment with clonazepam (2 mg/day) or placebo, during 6 weeks. Efficacy assessments included: change from baseline in the number of panic attacks; CGI scores for panic disorder; Hamilton rating scale for anxiety; and panic associated symptoms scale.

RESULTS

At the therapeutic endpoint, only one of 9 placebo patients (11.1%) were free of panic attacks, compared with 8 of 13 (61.5%) clonazepam patients (Fisher exact test; p=0,031).

CONCLUSION

the results provide evidence for the efficacy of clonazepam in panic disorder patients.

Hyperventilation in panic disorder patients and healthy first-degree relatives

Our aim was to observe the induction of panic attacks by a hyperventilation challenge test in panic disorder patients (DSM-IV) and their healthy first-degree relatives. We randomly selected 25 panic disorder patients, 31 healthy first-degree relatives of probands with panic disorder and 26 normal volunteers with no family history of panic disorder. All patients had no psychotropic drugs for at least one week. They were induced to hyperventilate (30 breaths/min) for 4 min and anxiety scales were applied before and after the test. A total of 44.0% (N = 11) panic disorder patients, 16.1% (N = 5) of first-degree relatives and 11.5% (N = 3) of control subjects had a panic attack after hyperventilating (chi(2) = 8.93, d.f. = 2, P = 0.011). In this challenge test the panic disorder patients were more sensitive to hyperventilation than first-degree relatives and normal volunteers. Although the hyperventilation test has a low sensitivity, our data suggest that there is no association between a family history of panic disorder and hyperreactivity to an acute hyperventilation challenge test. Perhaps cognitive variables should be considered to play a specific role in this association since symptoms of a panic attack and acute hyperventilation overlap.

Double-blind acute clonazepam vs. placebo in carbon dioxide-induced panic attacks

The inhalation of 35% carbon dioxide has consistently been shown to provoke panic attacks in panic disorder patients. We aim to determine if an acute dose of clonazepam (2 mg) attenuates the panic attacks induced by an inhalation of 35% carbon dioxide in panic disorder. Twenty-two panic disorder patients who had been drug-free for 1 week participated in a carbon dioxide challenge test 1 h after a dose of either 2 mg of clonazepam or placebo with a randomized double-blind method. Also in a double-blind design during the tests the patients inhaled either atmospheric compressed air ('placebo control') or the carbon dioxide mixture. All patients participated in both tests which were done with a 20-min interval. Immediately before and after the inhalation, the anxiety levels and the symptoms of panic were always assessed. In the clonazepam group (n=11) two patients (18.2%) had a mild panic attack and in the placebo group (n=11) nine patients (81.8%) had a moderate to severe panic attack in the CO(2) challenge test. No patient had panic attacks during inhalation of atmospheric compressed air although anticipatory anxiety levels tended to be higher than in the CO(2) tests. After the CO(2) test anxiety levels were significantly greater in the CO(2) group (three-way ANOVA with Geisser-Greenhouse adjustments, F(31.92,1.86)=17.15, d.f.=7, P=0.013). Although a small sample was studied, the findings suggest the efficacy of an acute dose of clonazepam in attenuating panic attacks induced by carbon dioxide inhalation.

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.