Environmental factors related to the outcome of panic disorder. A seven-year follow-up study

A 15-year follow-up study of patients with panic disorder

Background

Panic disorder (PD) is generally regarded as a chronic condition with considerable variation in severity of symptoms.

Aims

To describe the long-term outcome of naturalistically treated PD.

Methods

Fifty-five outpatients with PD, who participated in a placebo-controlled drug trial of the efficacy of alprazolam and imipramine 15 years ago were reassessed with the same instruments used in the original study.

Results

Complete recovery (no panic attacks and no longer on medication during the last 10 years) was seen in 18% of patients, and an additional 13% recovered but were still on medication. Fifty-one percent experienced recurrent anxiety attacks whereas 18% still met diagnostic criteria for PD. The incidence of agoraphobia decreased from 69% to 20%. Patients with agoraphobia at admission tended to have a poorer long-term outcome according to daily functioning compared with patients without agoraphobia at admission, although both groups reported improved daily functioning at follow-up. Maintenance medication was common. No benzodiazepine abuse was reported.

Conclusion

PD has a favourable outcome in a substantial proportion of patients. However, the illness is chronic and needs treatment. The short-term treatment given in the drug trial had no influence on the long-term outcome.

What can be learnt from the natural history of anxiety disorders?

Background

There is insufficient knowledge of the long-term course of panic disorder (PD).

Aim

To determine the long-term course and prognostic variables in patients diagnosed with PD.

Methods

Patients who were diagnosed of anxiety states between 1950 and 1961, were examined using a structured clinical interview (SCID-DSM-III-R) between 1984 and 1988 (n = 144). A re-examination was performed in the period 1997–2001 (N = 125). Mean length of follow-up from onset was 47 years.

Results

PD tends to be chronic. Among those who recovered, 93% had done so already by the 1980s. Lack of regular treatment compliance, progression to agoraphobia and number of episodes of panic disorder were associated with worse outcome. Agoraphobia without panic attacks and somatization symptoms were the most prevalent clinical status at follow-up.

Conclusion

After several decades, participants improve with regard to number of panic attacks, though most continue to have residual symptoms.

Depression does not affect the treatment outcome of CBT for panic and agoraphobia: results from a multicenter randomized trial

BACKGROUND

Controversy surrounds the questions whether co-occurring depression has negative effects on cognitive-behavioral therapy (CBT) outcomes in patients with panic disorder (PD) and agoraphobia (AG) and whether treatment for PD and AG (PD/AG) also reduces depressive symptomatology.

METHODS

Post-hoc analyses of randomized clinical trial data of 369 outpatients with primary PD/AG (DSM-IV-TR criteria) treated with a 12-session manualized CBT (n = 301) and a waitlist control group (n = 68). Patients with comorbid depression (DSM-IV-TR major depression, dysthymia, or both: 43.2% CBT, 42.7% controls) were compared to patients without depression regarding anxiety and depression outcomes (Clinical Global Impression Scale [CGI], Hamilton Anxiety Rating Scale [HAM-A], number of panic attacks, Mobility Inventory [MI], Panic and Agoraphobia Scale, Beck Depression Inventory) at post-treatment and follow-up (categorical). Further, the role of severity of depressive symptoms on anxiety/depression outcome measures was examined (dimensional).

RESULTS

Comorbid depression did not have a significant overall effect on anxiety outcomes at post-treatment and follow-up, except for slightly diminished post-treatment effect sizes for clinician-rated CGI (p = 0.03) and HAM-A (p = 0.008) when adjusting for baseline anxiety severity. In the dimensional model, higher baseline depression scores were associated with lower effect sizes at post-treatment (except for MI), but not at follow-up (except for HAM-A). Depressive symptoms improved irrespective of the presence of depression.

CONCLUSIONS

Exposure-based CBT for primary PD/AG effectively reduces anxiety and depressive symptoms, irrespective of comorbid depression or depressive symptomatology.

Power law relationships between health care utilization and symptom assessment among people with panic attacks

RATIONALE

Although people with panic attacks are high utilizers of health care, the role of symptom assessment in care-seeking is unclear. Previous studies suggest that symptom perceptions are linearly related to utilization but panic appraisal is not. The purpose of this study was to determine whether the relationships between symptom assessment and utilization are non-linear, displaying power law distributions.

METHODS

This community-based study of 97 subjects with panic attacks assessed utilization of family doctor offices, total ambulatory utilization, and hospitalizations as well as symptom perceptions and panic appraisals. Matrices of symptom assessment versus utilization were created, and log-log plots were constructed. To minimize the risk of overestimation of power law distributions, linear, quadratic and cubic regression models were computed.

RESULTS

None of the utilization versus symptom perceptions displayed power law distributions. However, all three measures of utilization showed power law relationships with panic appraisals, but in unique patterns.

CONCLUSIONS

Although power law relationships were not found between symptom perceptions and utilization, unique patterns of power laws were identified between panic appraisals and all three measures of utilization.

Moderators and mediators among panic, agoraphobia symptoms, and suicidal ideation in patients with panic disorder

OBJECTIVES

The most important change of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-V) is the use of dimensional approach to assess the severity of symptoms across different diagnosis. There are 2 purposes in this study: the first purpose was to identify the proportion of outpatients with panic disorder who have suicidal ideation. The second aim was to examine the relationships among panic, agoraphobic symptoms, and suicidal ideation in patients with panic disorder, adjusting by age, social support, and alcohol use.

METHODS

Sixty patients with panic disorder were recruited from outpatient psychiatric clinics in southern Taiwan. Suicidal ideation in the preceding 2 weeks was measured. The Panic and Agoraphobic Symptoms Checklist, Social Support Scale, Questionnaire for Adverse Effects of Medication for Panic Disorder, and Social Status Rating Scale were used to understand the severity of panic and agoraphobia, social support, drug adverse effects, and social status. Significant variables from the univariate analysis were included in a forward regression model. Then, we used structural equation modeling to fit the model.

RESULTS

We found that 31.7% of outpatients with panic disorder had had suicidal ideation in the preceding 2 weeks. Multiple regression analysis showed that younger age, current alcohol use, more severe panic symptoms, and less social support were associated with suicidal ideation. In addition, the structural equation model illustrated the recursive model from panic to agoraphobia and suicidal ideation. Agoraphobia had no association with suicidal ideation. Panic symptom was a mediator to suicidal ideation but not agoraphobic symptoms.

CONCLUSIONS

A high proportion of patients with panic disorder had suicidal ideation. We found that panic symptoms, social support, age, and alcohol use affected suicide and could be identified. The 3-level model from panic to agoraphobia revealed that panic was a predictor of agoraphobia and agoraphobia was not a predictor of panic. This verified the evolution of the diagnostic view of the DSM. Panic symptom was a mediator to suicidal ideation. With the dimensional model in DSM-V, panic symptoms can be used as a marker for greater morbidity and severity.

Predictors of clinical improvement in a randomized effectiveness trial for primary care patients with panic disorder

This study's aim was to prospectively examine and identify a model of demographic, clinical, and attitudinal variables that impact improvement among patients with panic disorder. Subjects were 232 primary care patients meeting criteria for DSM-IV panic disorder. Eligible patients were randomly assigned to a collaborative care intervention or to treatment as usual. Assessments occurred at 3-month intervals during the course of 1 year. In final multivariate logistic regression models, patients with higher anxiety sensitivity and higher neuroticism scores at baseline were less likely to show clinical improvement (using a criterion of 20 or less on the Anxiety Sensitivity Index) at 3 months. Those who were non-white, had higher anxiety sensitivity, and higher overall phobic avoidance at baseline were less likely to show clinical improvement at 12 months. A greater understanding of these predictors may help clinicians identify who is at greatest risk for persistent panic-related symptoms and to plan the intensity of interventions accordingly.

Correlations of quality of life with adverse effects of medication, social support, course of illness, psychopathology, and demographic characteristics in patients with panic disorder

Care of patients with panic disorder has raised quality-of-life (QOL) issues. The purpose of this study was to identify the level of QOL in patients with panic disorder and to examine the relationships between QOL and adverse effects of medication, social support, course of illness, psychopathology, and demographic characteristics. We recruited 57 patients with panic disorder from outpatient psychiatric clinics. We measured their QOL levels with the Short Form of the World Health Organization Questionnaire on Quality of Life-Taiwan Version (the WHOQOL-BREF Taiwan version) and examined the correlates of QOL. The analysis revealed that multiple factors were associated with poor QOL in patients with panic disorder, including severe adverse effects of medication for panic disorder, perceived low social support, severe current panic symptoms, total Beck Depression Inventory-II (BDI-II) score>/=17, young age, being unmarried, and early onset of panic disorder. The QOL of patients with panic disorder was correlated to multiple factors that were specific to individual subjects and influenced by interactions with treatment and the social environment. The results provide screening factors so that clinicians can intervene to improve QOL for their patients with panic disorder.

Long-term outcome of patients with dysthymia and panic disorder: a naturalistic 9-year follow-up study

The highly prevalent psychiatric disorders dysthymia and panic disorder have often a chronic or recurrent course with superimposed major depression. The prominent comorbidity between these diagnoses constitutes a confounding factor in the study of long-term outcome. We performed a 9-year follow-up of 38 patients with "pure" diagnoses, i.e. without comorbid dysthymia and panic disorder, selected from two 2-year naturalistic treatment studies with psychotherapy and antidepressant medication. The aims of the present study were to investigate 1) the stability of change, and 2) the impact of comorbid personality disorders (PDs) on long-term outcome. Patients were reassessed with SCID-I and SCID-II interviews, SCL-90/BSI and a detailed, modified life-charting interview, investigating course and treatment over time. About 50% of patients showed substantial improvement, of whom about half were in remission. Comorbid PD was a negative prognostic factor independently of Axis I diagnosis. Although patients with panic disorder had a lower frequency of comorbid PD, later onset, shorter duration of illness and better outcome after the original studies, there was no difference in the long-term outcome. The less stable outcome among panic patients suggests that standard treatments are not resulting in enduring remission. In order to achieve remission, it is necessary to 1) address comorbid PDs, 2) perform careful assessments of all comorbid diagnoses, and 3) build routines for the follow-up and augmentation of treatments.

Diagnosis and treatment of agoraphobia with panic disorder

Agoraphobia with panic disorder is a phobic-anxious syndrome where patients avoid situations or places in which they fear being embarrassed, or being unable to escape or get help if a panic attack occurs. During the last half-century, agoraphobia has been thought of as being closely linked to the recurring panic attack syndrome, so much so that in most cases it appears to be the typical development or complication of panic disorder. Despite the high prevalence of agoraphobia with panic disorder in patients in primary-care settings, the condition is frequently under-recognised and under-treated by medical providers. Antidepressants have been demonstrated to be effective in preventing panic attacks, and in improving anticipatory anxiety and avoidance behaviour. These drugs are also effective in the treatment of the frequently coexisting depressive symptomatology. Among antidepressant agents, SSRIs are generally well tolerated and effective for both anxious and depressive symptomatology, and these compounds should be considered the first choice for short-, medium- and long-term pharmacological treatment of agoraphobia with panic disorder. The few comparative studies conducted to date with various SSRIs reported no significant differences in terms of efficacy; however, the SSRIs that are less liable to produce withdrawal symptoms after abrupt discontinuation should be considered the treatments of first choice for long-term prophylaxis. Venlafaxine is not sufficiently studied in the long-term treatment of panic disorder, while TCAs may be considered as a second choice of treatment when patients do not seem to respond to or tolerate SSRIs. High-potency benzodiazepines have been shown to display a rapid onset of anti-anxiety effect, having beneficial effects during the first few days of treatment, and are therefore useful options for short-term treatment; however, these drugs are not first-choice medications in the medium and long term because of the frequent development of tolerance and dependence phenomena. Cognitive-behavioural therapy is the best studied non-pharmacological approach and can be applied to many patients, depending on its availability.

The reliability and validity of the Panic Disorder Self-Report: A new diagnostic screening measure of panic disorder

This study examined the Panic Disorder Self-Report (PDSR), a new self-report diagnostic measure of panic disorder based on the 4th edition of the Diagnostic and Statistical Manual of Mental Disorders (American Psychiatric Association, 1994). PDSR diagnoses were compared with structured interview diagnoses of individuals with generalized anxiety disorder, social phobia, and panic disorder and nonanxious controls. Receiver operating characteristic analyses revealed that the PDSR showed 100% specificity and 89% sensitivity. The PDSR also demonstrated retest reliability, convergent and discriminant validity, and kappa agreement of .93 with a structured interview. Finally, the PDSR demonstrated clinical validity. Students who were identified as having panic disorder using the PDSR did not have significantly different scores on the Panic Disorder Severity Scale--Self-Report form (P. R. Houck, D. A. Speigel, M. K. Shear, & P. Rucci, 2002) than a panic disordered community sample. However, both groups had significantly higher scores than students identified as not meeting criteria for panic disorder.

Influence of psychiatric comorbidity on recovery and recurrence in generalized anxiety disorder, social phobia, and panic disorder: a 12-year prospective study

OBJECTIVE

The authors sought to observe the long-term clinical course of anxiety disorders over 12 years and to examine the influence of comorbid psychiatric disorders on recovery from or recurrence of panic disorder, generalized anxiety disorder, and social phobia.

METHOD

Data were drawn from the Harvard/Brown Anxiety Disorders Research Program, a prospective, naturalistic, longitudinal, multicenter study of adults with a current or past history of anxiety disorders. Probabilities of recovery and recurrence were calculated by using standard survival analysis methods. Proportional hazards regression analyses with time-varying covariates were conducted to determine risk ratios for possible comorbid psychiatric predictors of recovery and recurrence.

RESULTS

Survival analyses revealed an overall chronic course for the majority of the anxiety disorders. Social phobia had the smallest probability of recovery after 12 years of follow-up. Moreover, patients who had prospectively observed recovery from their intake anxiety disorder had a high probability of recurrence over the follow-up period. The overall clinical course was worsened by several comorbid psychiatric conditions, including major depression and alcohol and other substance use disorders, and by comorbidity of generalized anxiety disorder and panic disorder with agoraphobia.

CONCLUSIONS

These data depict the anxiety disorders as insidious, with a chronic clinical course, low rates of recovery, and relatively high probabilities of recurrence. The presence of particular comorbid psychiatric disorders significantly lowered the likelihood of recovery from anxiety disorders and increased the likelihood of their recurrence. The findings add to the understanding of the nosology and treatment of these disorders.

The incidence and influence of early traumatic life events in patients with panic disorder: a comparison with other psychiatric outpatients

Early traumatic life events, including childhood physical and sexual abuse, has been associated with increased risk for panic disorder in adulthood. We examined the incidence and influence of early traumatic life events in outpatients with panic disorder (n = 101), compared to outpatients with other anxiety disorders (n = 58), major depression (n = 19), or chronic schizophrenia (n = 22). Data were obtained by means of Structured Clinical Interviews and self-report questionnaires. The incidence of childhood physical abuse ranged from 16 to 40% and for childhood sexual abuse from 13 to 43% with no significant differences among the four diagnostic groups. Across all outpatient groups a history of childhood physical or sexual abuse was positively correlated to clinical severity. Patients with panic disorder who reported childhood physical abuse were more likely to be diagnosed with comorbid depression, to have more comorbid Axis I disorders, to score higher on symptom checklists as well as reporting a greater history of suicide attempts in the past year (5% vs. 0%); or lifetime (36% vs. 15%). Similar findings were noted, but not as robustly, for patients with panic disorder who reported childhood sexual abuse. There is a high rate of adverse early childhood events across diagnostic groups in psychiatric outpatients and these events are likely to influence the severity of the disorder but are unlikely to be a unique risk factor for any one type of disorder.

Challenges and early experiences in the development of an anxiety clinic in the public health sector

This paper argues the importance of establishing specialist anxiety clinics within the public sector of the Australian health system. It describes the development of such a service and summarizes the characteristics of the first 1000 clients. Factors such as staffing, utilization trends, referral patterns, assessment and treatment procedures, and the clinical and demographic characteristics of the first 1000 cases are reviewed and discussed. The model of the clinic, which operates in partnership with community mental health and an academic research unit, has proven itself to be a suitable, cost-effective and efficient prototype in the treatment of anxiety disorders. Anxiety disorders exact a high social and economic cost. At a time of global funding cuts and savings in the mental health system, it is vital to think ethically as well as cost-efficiently, considerations that require that we offer the most efficient treatment to the greatest number of people.

The prediction of nonresponse to pharmacotherapy in panic disorder: a review

Several effective pharmacotherapeutic treatments exist for panic disorder; however, not all patients respond to treatment: between 20% to 40% are non-responders. Recent studies have reported several predictors of nonresponse to pharmacotherapy. In this review two questions are addressed: is there consensus with respect to predictors of nonresponse and are there any differences between short-term and long-term predictors? In this review both short-term and long-term outcome studies are discussed. Studies were included if at least DSM-III criteria were used and baseline variables were investigated as possible predictor of response, or nonresponse, to pharmacotherapy. Of each clinical predictor, tallies were made of the particular predictors employed and of those predictors that predicted nonresponse. It appears that a long duration of illness and severe agoraphobic avoidance are robust predictors of nonresponse, particularly in long-term studies. Personality disorders, or even personality traits, are possibly the most robust predictors of nonresponse. Several factors appear to be robust predictors of nonresponse: factors that are present before treatment and exert their influence on short-term and long-term treatment outcome. Prospective studies are needed to further investigate these factors and to test whether it is viable to intervene in an attempt to increase treatment response.

Panic disorder: the place of benzodiazepines and selective serotonin reuptake inhibitors

This article reviews the efficacy of the benzodiazepines and the selective serotonin reuptake inhibitor class of antidepressant in the treatment of panic disorder. The benzodiazepine alprazolam has been used successfully in the treatment of panic disorder, but its long-term use presents problems with dependence. Since panic may be mediated by a dysfunction of serotonin neuronal pathways, there is a rationale for treatment with antidepressants that modulate serotonergic systems. In clinical trials, members of the SSRI class of antidepressant reduced panic attack frequency to zero in 36-86% of patients and were well tolerated over long-term administration, all important factors in ensuring patient compliance. In addition, antidepressants are preferable to benzodiazepines in the treatment of panic and comorbid depression, of which there is a high prevalence among panic disorder patients. This review emphasises the need for long-term treatment of this chronic and disabling condition with a therapy that is well tolerated and provides complete and sustained recovery from panic attacks, and resolution of anticipatory anxiety.

Predictors of 1-year outcome for patients with panic disorder

The course of panic disorder (PD) is often prolonged, but factors that affect the social outcome have not yet been made clear. The aim of this study was to find predictors of outcome for patients with PD. The subjects were 65 outpatients (28 men and 37 women) with PD (DSM-III-R) who were treated at our hospital for more than 1 year. The factors affecting 1-year outcome were evaluated by multiple regression analysis. We found that the following were predictors of poor social outcome in PD: (1) severe agoraphobia at the first psychiatric examination and (2) long duration of illness before the first psychiatric consultation. Furthermore, the complication of hypochondriacal symptoms predicted a poor outcome for PD. Early attention to agoraphobia and hypochondriasis is essential for the treatment of PD, and early introduction to psychiatric treatment is recommended.

The long-term course of panic disorder and its predictors

Whereas lifetime prevalence rates of panic disorder--as established in epidemiologic surveys--range between 1.6 and 3.5%, 1-month rates usually amount to much less than one half of the lifetime rates. This finding indicates that a substantial proportion of patients who had panic disorder at some stage in their life must have remitted. In contrast to these results, clinicians tend to regard panic disorder as a chronic condition because, as a rule, they see panic patients only several years after onset of the disorder. A number of small, prospective, long-term studies of such clinical populations indicate that after several years, between 17 and 70% of patients still have panic attacks, and between 36 and 82% have phobic avoidance. In the largest and longest follow-up study published to date, 45% of all patients showed an unremitting--although in a certain proportion waxing and waning--course, 24% followed a pattern of remissions and relapses, whereas 31% went back into a stable remission. The evidence of factors predicting the course of panic disorder in clinical populations suggests that long duration and agoraphobia at baseline--not the severity and frequency of panic attacks--are predictors of an unfavorable course. Additional studies are needed to determine whether personality factors, depression, and other variables are also of predictive relevance. Also, factors working during follow-up, such as positive and negative life events, coping behaviors, and treatment, should be considered in future studies.

First-incidence anxiety in the Lundby Study: course and predictors of outcome

The aim of the present study was to analyse first-incidence anxiety in the Lundby Study with regard to course and predictors of outcome between 1947 and 1972. The Lundby concept of anxiety corresponds broadly to that of anxiety disorders in DSM-III-R. The Lundby Study is a prospective, psychiatric study of a geographically defined total population. The present study includes 124 subjects (46 men and 78 women) who between 1947 and 1972 developed anxiety as their first mental illness in life. The median total duration of illness was 1.6 years in men and 1.4 years in women. In both sexes episodes of mild impairment dominated. In total, 54% of the men and 71% of the women were mentally healthy at the follow-up in 1972. A minority of the probands (27%) received psychiatric treatment. They significantly more often suffered from panic disorder with agoraphobia during their first episode, and from comorbidity of other mental illnesses, than did untreated subjects. They also had a significantly longer total duration of illness, a variable with a negative predictive influence on the probability of being mentally healthy in 1972. Men with anxiety showed a 55% increase in alcoholism compared to standard values. They also displayed an increased risk of relapsing into mental illness compared to female cases, a result which, in the light of earlier findings of increased mortality rates, suggests that further investigations of men with anxiety syndromes in the general population are warranted.

Comorbid psychiatric disorders in subjects with panic attacks

Several psychiatric disorders are associated with panic disorder (PD), although the nature of their relationships is unknown. The purpose of this study was to a) document comorbid associations with both PD and infrequent panic (IP), and b) investigate the nature of the relationships among these disorders. This community-based study included 97 adults who met DSM-III-R criteria for panic attacks compared with 97 matched controls. Psychiatric comorbidity was assessed using the SCID and SCL-90. Subjects with either PD or IP had higher rates of psychiatric comorbidity than controls. PD differed from IP only in its higher rate of phobic avoidance. Factor analysis found three factors: PD with phobic avoidance; substance abuse; major depression with obsessive compulsive disorder, social and simple phobias. Only phobic avoidance began secondary to panic onset. In conclusion, this study supports the PD-agoraphobia DSM-IV grouping while lending support to the common diathesis hypothesis for anxiety and affective disorders.

Long-term outcome of panic disorder treatment. A review of the literature

This review was designed to provide a detailed analysis of long-term outcome data from treatment studies for panic disorder, with the goal of ascertaining differential efficacy of the available treatments. Studies were included if they were published after 1980 and if follow-up took place at least 6 months after treatment termination. Thirty-one studies were located. A variety of methodological problems were found in these studies, including lack of clarity of diagnosis, lack of clarity in the treatment administered, and inadequately tracked nonstudy treatments during the study and follow-up periods, which limited the information that could be obtained about long-term outcome. Long-term outcome studies that closely track the additional treatments that patients receive are necessary to draw more definitive conclusions about differential treatment efficacy for panic disorder. Available data suggest that there is limited evidence for long-term maintenance of short-term treatment gains in panic disorder patients in the absence of continued treatment.

Developments in the drug treatment of panic disorder: what is the place of the selective serotonin reuptake inhibitors?

Panic disorder is becoming better recognised and understood as a chronic, debilitating but treatable condition. Drug treatment options shown by adequate research to be beneficial in this condition include mainly the benzodiazepine alprazolam, the tricyclic antidepressants (TCAs) imipramine and clomipramine, the monoamine oxidase inhibitor (MAOI) phenelzine, and the newer selective serotonin reuptake inhibitors (SSRIs) fluvoxamine and paroxetine. Alprazolam, although approved for use in panic disorder in the US and very widely used, is associated with a risk of dependence and withdrawal syndromes. Given that depression frequently occurs as a comorbid condition with panic disorder the use of antidepressants is a logical choice. Among the antidepressants, MAOIs are little-used in panic disorder, mainly because of their potential for precipitating hypertensive crises if tyramine is ingested. TCAs are widely used and are effective but they are associated with initial activation, or 'jitteriness', have a 4-6-week time lag before onset of beneficial effect and produce troublesome side effects in a high proportion of patients, particularly during long-term use. TCAs are also cardiotoxic in overdosage, and panic disorder patients with comorbid depression are at high risk of attempted suicide. Serotonin dysregulation has been implicated in the pathogenesis of anxiety disorders in general, and panic disorder in particular. Among the TCAs, those with an effect on serotonin reuptake are most effective in panic disorder. SSRIs are specifically active on serotonin reuptake and do not have anticholinergic effects or act on the noradrenergic system. There is a clear pharmacological rationale for believing that SSRIs should be as effective as TCAs in panic disorder and better tolerated. Accumulating clinical research evidence supports this hypothesis. Further comparative studies with standard agents and additional long-term studies to support the initial long-term data with paroxetine are needed to confirm SSRIs as drug treatment of choice in panic disorder.

Panic attacks and panic disorder in Japanese non-patient population: epidemiology and psychosocial correlates

To investigate the prevalence rates of panic disorder and panic attacks in the general population of Japan, a set of questionnaires were administered to 207 people aged 18 or over, who were then interviewed. Seven (3.4%) had experienced one or more unexpected panic attacks in their lifetime. Two subjects (1.0%) had had panic disorder (DSM-III-R), and five (2.4%) had had panic attacks not meeting the criteria for panic disorder. Seventy percent of the persons with panic disorder or panic attacks had sought medical care. There was comorbidity with agoraphobia in two cases, and with major depression in five. Harsh discipline, frequent quarrel, between parents, and serious illness before the age of 16 were more frequent in individuals suffering from panic attacks, compared to those without.

Course and outcome in panic disorder: a review of recent follow-up studies

This paper reviews the methodologic considerations that are important in evaluating and interpreting panic disorder outcome studies and the results of the most well-designed of these studies. Sixteen studies that used modern diagnostic criteria and interviewed at least 25 patients on at least two occasions over a minimum follow-up period of one year are reviewed. Results show that, despite the availability of effective anti-panic treatments, panic disorder remains a chronic illness. While most patients improve, few are "cured." The presence of agoraphobia, major depression and personality disorder seems to predict poorer outcome. The importance of measuring multiple clinical dimensions of panic is emphasized, along with the need to reach a consensus about the definition of "outcome" and the particular instruments to use to measure it.