A randomized effectiveness trial of collaborative care for patients with panic disorder in primary care

BACKGROUND

Effectiveness studies have tested interventions to improve quality of care for depression in primary care, but none, to our knowledge, have been completed for panic disorder (PD) in this setting. This study sought to test the clinical effectiveness of PD pharmacotherapy embedded in a disease management framework of "collaborative care" (CC).

METHODS

One hundred fifteen patients with PD from 3 primary care clinics were randomized to CC or "usual care" (UC). Patients in CC (n = 57) received educational videotapes and pamphlets; pharmacotherapy with the selective serotonin reuptake inhibitor paroxetine; 2 psychiatrist visits and 2 telephone calls in the first 8 weeks; and up to 5 telephone calls between 3 and 12 months' follow-up. Usual care patients (n = 58) were treated by their primary care physician. Telephone assessments of panic, anxiety sensitivity, depression, and disability variables were performed at 3, 6, 9, and 12 months' follow-up. Adequacy of pharmacotherapy was assessed with an algorithm based on a review of efficacy studies.

RESULTS

Patients in CC were more likely to receive adequate (type, dose, duration) medication and more likely to adhere to this medication at 3 and 6 months. Random regression analyses showed that CC patients improved significantly more over time compared with UC patients on anxiety, depression, and disability measures, with the greatest effects at 3 and 6 months.

CONCLUSIONS

Compared with UC, CC interventions significantly improved both quality of care and clinical and functional outcomes in primary care PD patients. Clinical differences were greatest in the first 6 months, corresponding to the greater quality of care and the greater intensity of intervention.

Panic disorder in primary care: biopsychosocial differences between recognized and unrecognized patients

Studies suggest that the recognition of depression by primary care physicians (PCPs) is most likely in more symptomatic and impaired patients. As part of a randomized effectiveness study in primary care patients with panic disorder, we examined the baseline characteristics of study patients who were recruited by waiting room screen procedure (n=69) versus patients who were referred to the study by their PCP (n=41). Patients referred by their physicians had a significantly higher frequency of panic attacks, more intense attacks, and more anticipatory anxiety on the Panic Disorder Severity Scale, while screen-identified patients were more medically ill and had worse physical functioning on the SP36. There were no differences in anxiety sensitivity, phobic avoidance, depression, other SF36 measures, disability, or medical service utilization. In conclusion, differences in referred versus screened patients are mostly specific for panic attack-related symptoms, consistent with the notion that patients with more prominent physical symptoms (i.e., panic attacks) are more often recognized and referred in busy clinical settings. The better medical status and physical functioning of referred patients may indicate greater physician recognition of panic in patients who appear less medically ill. However, the many clinical and functional similarities between these two patient samples suggests that symptomatic primary care patients with panic may not always be identified by their PCPs and argues for the value of population-based screening for panic in primary care.

Cardiovascular and catecholamine response to orthostasis in panic and obsessive-compulsive disorder and normal controls: effects of anxiety and novelty

OBJECTIVE

Studies of the cardiovascular and catecholamine response to orthostatic challenge in panic disorder patients have yielded conflicting results. Failure to control for the effects of both anxiety and novelty, which contribute to subjects' response to orthostatic challenge in control patients, could possibly account for this.

METHODS

The blood pressure, pulse, plasma norepinephrine and epinephrine responses to orthostasis were examined in patients with panic disorder, obsessive-compulsive disorder (to control for nonspecific anxiety effects), and controls, on two separate days a week apart (to control for novelty).

RESULTS

All measures showed robust and significant increases with orthostatic challenge that were generally similar across groups. Pressure responses were greater on average on the first compared with the second day and panic disorder patients had higher plasma norepinephrine levels throughout the study and a diminished diastolic blood pressure response on the first day.

CONCLUSIONS

These findings in general support the absence of consistent peripheral autonomic nervous system differences in response to orthostatic challenge in panic disorder patients.

Nefazodone treatment of major depression in alcohol-dependent patients: a double-blind, placebo-controlled trial

Depression is the most common comorbid psychiatric illness in patients with alcohol dependence. This double-blind study tested the efficacy of nefazodone versus placebo for the treatment of depression in actively drinking alcohol-dependent patients who were also participating in weekly group treatment for alcoholism. Sixty-four subjects with major depression disorder and alcohol dependence with a history of at least one prior episode of depression when not drinking were randomly assigned to receive 12 weeks of either nefazodone or placebo and participated in a weekly psychoeducational group on alcoholism. Subjects were assessed every 2 weeks for depression, anxiety, side effects, and drinking frequency. Subjects taking nefazodone were significantly more likely to complete the study (62%) than those taking placebo (34%). Analyses of covariance using drinks per week as a time-dependent covariate showed lower Hamilton Rating Scale for Depression scores at week 8 for end-point analysis and at weeks 8 and 12 for completers. The endpoint analysis demonstrated a significantly greater response in the nefazodone group (48%) than in the placebo group (16%). Both groups showed a similarly significant decrease in the average number of alcoholic drinks consumed per day over the course of the study. Although the number of adverse effects was significantly greater for the nefazodone group, there were no severe adverse events, and nefazodone was well tolerated. Nefazodone is a safe and effective antidepressant to use in a population of alcohol-dependent patients with depression who have a high degree of comorbidity. Nefazodone treatment was superior to placebo in alleviating depression in these patients but did not add any advantage over the psychoeducational group in terms of drinking outcomes.

Relationship between borderline personality disorder and Axis I diagnosis in severity of depression and anxiety

BACKGROUND

This study tested the hypothesis that subjects with borderline personality disorder irrespective of the presence or absence of an Axis I mood or anxiety disorder would exhibit greater severity of depression and anxiety than subjects with either a personality disorder other than borderline personality disorder or no personality disorder.

METHOD

Two hundred eighty-three subjects from an outpatient psychiatry clinic were administered the following assessments: the Structured Clinical Interview for DSM-III-R (SCID) for Axes I and II, the Hamilton Rating Scales for Depression and Anxiety, the Beck Depression Inventory, and the Spielberger State-Trait Anxiety Inventory. Subjects were categorized into borderline personality disorder, other personality disorder, and no personality disorder categories and into present versus absent categories on Axis I diagnosis of depression and of anxiety. A 2-factor multiple analysis of variance compared personality disorder status and Axis I diagnosis on severity of depression by observer rating and self-report. The analysis was repeated for anxiety.

RESULTS

As hypothesized, significant main effects were found for borderline personality disorder and for both depression and anxiety. Subjects with borderline personality disorder showed greater severity on both depression and anxiety rating scales than did patients with another personality disorder, who showed greater severity than did patients with no personality disorder. Axis I diagnosis was also associated with greater severity on depression or anxiety rating scales. These differences were found for both observer ratings and self-report. An interaction was also found for depression: Subjects with borderline personality disorder but without an Axis I diagnosis of depression rated themselves as more severely depressed on the Beck Depression Inventory than did subjects with another or no personality disorder who also had an Axis I diagnosis of depression.

CONCLUSION

Implications from the study are discussed including the need to assess for borderline personality disorder in research studies of depression and anxiety and to integrate treatments for borderline personality disorder into depression and anxiety treatment to maximize clinical outcomes.

Relationship between a GABAA alpha 6 Pro385Ser substitution and benzodiazepine sensitivity

OBJECTIVE

In humans, interindividual variation in sensitivity to benzodiazepine drugs may correlate with behavioral variation, including vulnerability to disease states such as alcoholism. In the rat, variation in alcohol and benzodiazepine sensitivity has been correlated with an inherited variant of the GABAA alpha 6 receptor. The authors detected a Pro385Ser [1236C > T] amino acid substitution in the human GABAA alpha 6 that may influence alcohol sensitivity. In this pilot study, they evaluated the contribution of this polymorphism to benzodiazepine sensitivity.

METHOD

Sensitivity to diazepam was assessed in 51 children of alcoholics by using two eye movement measures: peak saccadic velocity and average smooth pursuit gain. Association analysis was performed with saccadic velocity and smooth pursuit gain as dependent variables and comparing Pro385/Ser385 heterozygotes and Pro385/Pro385 homozygotes.

RESULTS

The Pro385Ser genotype was associated with less diazepam-induced impairment of saccadic velocity but not with smooth pursuit gain.

CONCLUSIONS

The Pro385Ser genotype may play a role in benzodiazepine sensitivity and conditions, such as alcoholism, that may be correlated with this trait.

Does ketamine-mediated N-methyl-D-aspartate receptor antagonism cause schizophrenia-like oculomotor abnormalities?

Evidence from histological and pharmacological challenge studies indicates that N-methyl-D-aspartate (NMDA) receptor hypofunction may play an important role in the pathophysiology of schizophrenia. Our goal was to characterize effects of NMDA hypofunction further, as related to schizophrenia-associated neuropsychological impairment. We administered progressively higher doses of ketamine (target plasma concentrations of 50, 100, 150, and 200 ng/ml) to 10 psychiatrically healthy young men in a randomized, single-blind, placebo-controlled design and assessed oculomotor, cognitive, and symptomatic changes. Mean ketamine plasma concentrations approximated target plasma concentrations at each infusion step. Verbal recall, recognition memory, verbal fluency, pursuit tracking, visually guided saccades, and fixation all deteriorated significantly during ketamine infusion; lateral gaze nystagmus explained some, but not all, of the smooth pursuit abnormalities. We concluded that ketamine induces changes in recall and recognition memory and verbal fluency reminiscent of schizophreniform psychosis. During smooth pursuit eye tracking, ketamine induces nystagmus as well as abnormalities characteristic of schizophrenia. These findings help delineate the similarities and differences between schizophreniform and NMDA-blockade-induced cognitive and oculomotor abnormalities.

Predictors and outcome of discharge against medical advice from the psychiatric units of a general hospital

OBJECTIVE

The study examined predictors of discharge against medical advice (AMA) and outcomes of psychiatric patients with AMA discharges, as measured by poorer symptom ratings at discharge and higher rates of rehospitalization.

METHODS

A total of 195 patients discharged AMA from general hospital psychiatric units were compared retrospectively with 2,230 regularly discharged patients. AMA status was defined as signing out against medical advice, being absent without leave, or being administratively discharged. All patients received standardized assessments within 24 hours of admission and at discharge. Demographic characteristics, psychiatric history, DSA-IV psychiatric and substance use diagnoses, and scores on an expanded 32-item version of the Psychiatric Symptom Assessment Scale were compared.

RESULTS

The groups did not differ in primary psychiatric diagnoses. Patients discharged AMA were significantly less likely to be Caucasian or to be functionally impaired due to physical illness. They were more likely to live alone, have a substance use diagnosis, use more psychoactive substances, and have more previous hospitalizations. Patients discharged AMA had significantly shorter lengths of stay, higher rehospitalization rates, and more severe symptoms at discharge, even when length of stay was taken into account. The differences between the groups in male gender and young age were better accounted for by a greater likelihood of substance abuse in these groups.

CONCLUSIONS

The results suggest a profile of patients who may be discharged AMA. Such patients have worse outcomes and are more likely to be high utilizers of inpatient resources. Aggressive identification of patients likely to be discharged AMA and early discharge planning for appropriate outpatient treatment are recommended.

Psychedelic effects of ketamine in healthy volunteers: relationship to steady-state plasma concentrations

BACKGROUND

Ketamine has been associated with a unique spectrum of subjective "psychedelic" effects in patients emerging from anesthesia. This study quantified these effects of ketamine and related them to steady-state plasma concentrations.

METHODS

Ketamine or saline was administered in a single-blinded crossover protocol to 10 psychiatrically healthy volunteers using computer-assisted continuous infusion. A stepwise series of target plasma concentrations, 0, 50, 100, 150, and 200 ng/ml were maintained for 30 min each. After 20 min at each step, the volunteers completed a visual analog (VAS) rating of 13 symptom scales. Peripheral venous plasma ketamine concentrations were determined after 28 min at each step. One hour after discontinuation of the infusion, a psychological inventory, the hallucinogen rating scale, was completed.

RESULTS

The relation of mean ketamine plasma concentrations to the target concentrations was highly linear, with a correlation coefficient of R = 0.997 (P = 0.0027). Ketamine produced dose-related psychedelic effects. The relation between steady-state ketamine plasma concentration and VAS scores was highly linear for all VAS items, with linear regression coefficients ranging from R = 0.93 to 0.99 (P < 0.024 to P < 0.0005). Hallucinogen rating scale scores were similar to those found in a previous study with psychedelic doses of N,N-dimethyltryptamine, an illicit LSD-25-like drug.

CONCLUSIONS

Subanesthetic doses of ketamine produce psychedelic effects in healthy volunteers. The relation between steady-state venous plasma ketamine concentrations and effects is highly linear between 50 and 200 ng/ml.

Determinants of pharmacologic treatment failure in panic disorder

BACKGROUND

We systematically assessed reasons for failure of pharmacologic treatment for panic disorder in patients referred to a specialty anxiety and mood disorders clinic and examined possible determinants of treatment-resistant panic disorder.

METHOD

Interview data were obtained from 106 patients with DSM-III-R panic disorder seen in consultation. Data for each of 252 past medication trials included dose, duration of treatment, side effects, outcome, and reason for discontinuation. T tests and chi-square analyses were used to compare demographic and clinical characteristics of patients failing versus responding to adequate trials and those with and without intolerable medication side effects.

RESULTS

Of 252 medication trials, 190 used effective antipanic medications, and only 59 (23%) were adequate in dose and duration. The most common reason for treatment failure was intolerable side effects, occurring in 51 (27%) of 190 trials using effective antipanic medications. Patients discontinuing treatment due to adverse effects had higher Hamilton Rating Scale for Anxiety scores and were less likely to have a history of substance abuse. Discontinuation due to side effects was significantly more common with tricyclic antidepressants than with benzodiazepines. True treatment resistance was reported in 14 (24%) of 59 adequate medication trials. Treatment-resistant patients were younger and had a higher lifetime rate of major depression.

CONCLUSION

Although use of ineffective medications or inadequate trials were important factors, the most common reason for treatment failure was side effects, especially with tricyclic antidepressants. True treatment resistance was less common, since few medication trials were adequate in dose and duration, and may be associated with comorbidity.

Relationships between neuropsychological and oculomotor measures in schizophrenia patients and normal controls

Establishing the relationship between oculomotor and neuropsychological impairments might facilitate a more coherent description of schizophrenia-associated neurocognitive deficits. Therefore, we assessed several aspects of neuropsychological and oculomotor function in 25 medicated schizophrenia patients and 24 age-matched controls. Neuropsychological tasks included the Wisconsin Cart Sort Test (WCST), the Trail Making Test (TMT), the Rey Auditory Verbal Learning Test, and finger tapping speed. Oculomotor functions assessed included smooth pursuit, initiation of smooth pursuit, predictive pursuit, fixation, visually guided saccades, remembered saccades, and antisaccades. Among the schizophrenia patients, predictive pursuit performance correlated significantly with finger tapping (dominant hand), TMT (both parts), and one WCST measure (categories completed). The only other significant correlation among the schizophrenia patients was between antisaccade performance and part A of the TMT. Perseverative errors during the WCST and antisaccade performance were the only measures significantly correlated among the normals. Closely related neurocognitive deficits may be responsible for impairments in TMT, WCST, predictive pursuit, and antisaccade performance in schizophrenia.

Determinants of suicidal ideation: the role of substance use disorders

BACKGROUND

This study tested the hypothesis that the amount of psychoactive substance consumed (frequency and/or quantity), life problems resulting from this use, and a DSM-IV diagnosis of substance abuse/dependence are independent risk factors associated with increased suicidal ideation in a population of psychiatric inpatients with major depressive disorder.

METHOD

891 hospitalized patients with a primary diagnosis of nonpsychotic major depressive disorder (MDD) received a standardized, psychiatrist-administered assessment battery. To examine the relationship between admission suicidality and demographic, psychiatric history, and admission variables, chi-square analyses were used for categorical data and one-way ANOVAs were used for continuous indices. Stepwise hierarchical multiple regression analyses were performed to determine the set of variables that was independently related to admission suicidality level.

RESULTS

There was general agreement between our findings and previous literature in regard to the association between severity of Axis I diagnosis, depressed mood, hopelessness, male gender, unemployment, involuntary treatment, and alcohol/drug problems and higher suicidal ideation. In our sample of hospitalized patients with unipolar major depressive disorder, higher current drug and/or alcohol dependency and high current use of alcohol or other substances of abuse were independently associated with higher levels of suicidal ideation.

CONCLUSION

This association with higher suicidal ideation lends support to the importance of treating patients for both alcohol/drug problems and depression in an effort to decrease their risk for future suicide. We hope that our findings will improve the care that patients with dual diagnoses receive.

Reduced benzodiazepine sensitivity in patients with panic disorder: comparison with patients with obsessive-compulsive disorder and normal subjects

OBJECTIVE

The authors sought to replicate their previous finding of reduced response to diazepam in patients with panic disorder, to test whether this effect was specific for panic disorder, and to determine whether this reduced response was merely an artifact of resistance to sedation from anxiety-related overarousal.

METHOD

The effects of four increasing intravenous doses of diazepam on saccadic eye movement velocity and accuracy (the latter being a saccadic variable that is unaffected by sedation), short-term memory, and self- and observer-rated sedation were assessed in 18 patients with panic disorder, 15 patients with obsessive-compulsive disorder, and 14 normal comparison subjects. The ratios of effect to blood level areas under the curve for both ascending and descending limbs of the effect/blood level curves were compared for each variable.

RESULTS

Patients with panic disorder showed significantly less diazepam effect on saccadic velocity and accuracy for the ascending limb of the blood level curve than comparison subjects. Patients with obsessive-compulsive disorder showed similar differences from comparison subjects but only for saccadic velocity. There were no group differences in diazepam effects on memory and sedation.

CONCLUSIONS

Patients with panic disorder are less sensitive than comparison subjects to diazepam. Although this difference is not an artifact of resistance to sedation, it may not be specific for panic disorder but rather may reflect a more nonspecific aspect of anxiety disorders.

Effect of benzodiazepines on plasma levels of homovanillic acid in anxious patients and control subjects

The effects of four logarithmically increasing doses of intravenous diazepam or placebo on plasma homovanillic acid (HVA) were determined in benzodiazepine-naive patients with panic disorder (PD) or generalized anxiety disorder (GAD), and in healthy controls. Plasma HVA was measured at baseline and 3 min after the first and fourth doses of diazepam/placebo. Mean baseline plasma HVA levels were significantly lower in PD patients compared with GAD patients and controls. Although plasma HVA levels decreased significantly with time in all groups, there was no diazepam effect. This study suggests that low dopaminergic activity may occur in a subset of anxious patients (PD), and that diazepam does not significantly affect dopaminergic activity as measured by plasma HVA in humans.

Tridimensional personality traits in sons of alcoholic and nonalcoholic fathers

Sons of alcoholics (SOAs; n = 27) and sons of nonalcoholics (SONAs; n = 23) were compared across Tridimensional Personality Questionnaire (TPQ) and Sensation Seeking scales and measures of plasma homovanillic acid and platelet monoamine oxidase activity. SOAs and SONAs did not differ significantly on any measure. The pattern of correlations between TPQ and Sensation Seeking scales provided some support for the construct validity of TPQ measures. Scores on the TPQ Novelty Seeking scale and platelet monoamine oxidase activity were significantly inversely associated (r = -0.52, p < 0.02) among SOAs, but not among SONAs (r = -0.06).

Effect of diazepam on plasma gamma-aminobutyric acid in sons of alcoholic fathers

A subgroup of abstinent alcoholics, display low levels of plasma gamma-aminobutyric acid (GABA). Two previous studies of plasma GABA in sons of alcoholic fathers (SOAs) have yielded conflicting results. The aim of the current study was to measure plasma GABA both at baseline and after challenge with diazepam, a GABAA receptor agonist, in a group of SOAs already shown to display decreased eye movement, memory, and sedative effects of diazepam. Twenty-seven SOAs and 23 male control subjects received four logarithmically increasing doses of diazepam or placebo in randomized order on 2 days at least 1 week apart. Plasma GABA was measured at baseline and after the last dose. There were no significant differences between SOAs and controls in baseline plasma GABA levels. In the whole sample, there were significant correlations between baseline plasma GABA and both high novelty-seeking and low-harm avoidance scores on the Tridimensional Personality Questionnaire. Both SOAs and controls displayed decreases in plasma GABA over time on both testing days, but there was no effect of diazepam on plasma GABA and no significant difference between groups in plasma GABA response to diazepam. These results suggest that neither low plasma GABA at baseline nor altered plasma GABA response to diazepam is associated with increased genetic risk for alcoholism.

Long-term course and outcome in panic disorder: a naturalistic follow-up study

Fifty-five of 102 consecutively evaluated patients with panic disorder seen in consultation at a specialty anxiety and mood disorders clinic were reinterviewed from 15 to 60 months later after naturalistic treatment in the community. Over the follow-up period, most patients displayed improvement in panic attack frequency and severity, phobic avoidance, depression, and major role functioning, although only five (10%) were asymptomatic on all measures at follow-up. The majority of patients with impaired interpersonal functioning showed no improvement on this measure. Thirty percent of the patients were panic-free at 12 months and 28% at the time of follow-up, with 43% experiencing at least three panic-free months during the follow-up period. Comorbid agoraphobia, major depression, and Axis II disorders were associated with worse outcome on selected measures of symptomatic and functional impairment. However, the strongest predictors of overall improvement were avoidance coping for outcome at 12 months and Axis I comorbidity for outcome at the time of the follow-up evaluation.

Assessment of family history of alcoholism in sons of alcoholic fathers

Results of studies of sons of alcoholics (SOAs) may vary depending on the density of the family history of alcoholism of the SOA subjects selected. To assess how reliably SOA subjects report a history of alcoholism in first- and second-degree relatives, we compared family histories obtained from 20 SOAs with those provided by their fathers. In all 20 cases, SOAs and their fathers agreed that the father met criteria for alcohol dependence but for no other primary Axis I psychiatric disorder. However, agreement was not as good for whether other paternal relatives in addition to the father were affected (kappa = 0.36) or for whether the family history was unigenerational or multigenerational for alcoholism (kappa = 0.44). Whether this discrepancy was due to under-reporting by the son or over-reporting by the father is unclear. These results suggest that 18-25 year old SOAs are reliable sources regarding alcohol dependence in their fathers, but that for determination of density of the family history of alcoholism, other relatives should also be interviewed directly.

Human oculomotor function: reliability and diurnal variation

To provide information on test-retest reliability for seven oculomotor paradigms currently used in studies of schizophrenia and other neuropsychiatric conditions, we tested eight controls at four weekly intervals, twice in the morning (8-10 AM) and twice in the afternoon (3-5 PM). Intraclass correlation coefficients were significant (p < .05) for both AM and PM pairs of measures as well as for mean AM and PM pairs for closed-loop pursuit gain, open-loop pursuit gain (using velocity as the measure), saccadic frequency during pursuit and fixation, visually and nonvisually guided saccadic latency and velocity, antisaccadic latency, and premature reflexive saccades during the memory-guided saccade task. Acceleration as a measure of open-loop gain (for slower targets) and accuracy of saccades to a moving target were only reliable at PM testing time. Nonvisually guided saccadic accuracy and inappropriate reflexive saccades during the antisaccade task were not reliable, possibly due to the narrow range of values for these measures. Except for approximately 10% fewer saccades during pursuit and fixation in the morning, there were no consistent diurnal differences. These findings suggest that, in a small sample of subjects, most measures of oculomotor function are stable across time and may reflect underlying neurophysiologic traits.

Benzodiazepine sensitivity in panic disorder: effects of chronic alprazolam treatment

The aim of the current study was to determine the degree to which patients with panic disorder develop tolerance to subjective and physiological effects of benzodiazepine after chronic treatment with alprazolam. Response to acute administration of diazepam was assessed in 19 panic disorder patients receiving chronic treatment with alprazolam and 23 untreated panic disorder patients. At baseline in the laboratory, the two groups did not differ in peak saccadic eye movement velocity, saccade latency, short-term memory, plasma cortisol and growth hormone concentrations, heart rate, and self-rated levels of sedation and anxiety. Compared with untreated patients, alprazolam-treated patients displayed significantly less diazepam-induced change in peak saccadic velocity, saccade latency, growth hormone secretion, memory, and self-rated levels of sedation. There was no difference between groups in diazepam effects on plasma cortisol concentrations or self-rated anxiety. Within alprazolam-treated patients, diazepam-induced slowing of peak saccade velocity was significantly inversely correlated with illness severity, as measured by reported panic attacks per week and severity of phobic avoidance, but not with alprazolam dose, blood level, or duration of treatment. Because the alprazolam-treated group reported more panic attacks per week than the untreated panic patients, treated patients were divided into those who were asymptomatic versus those with continuing panic attacks. The subgroup of nine alprazolam-treated subjects who were asymptomatic also showed significantly less diazepam effects than the group of untreated panic disorder patients, suggesting that overall group differences were at least partially attributable to the development of tolerance to selected benzodiazepine effects with chronic alprazolam treatment.

Effects of diphenhydramine on human eye movements

Peak saccadic eye movement velocity (SEV) and average smooth pursuit gain (SP) are reduced in a dose-dependent manner by diazepam and provide reliable, quantitative measures of benzodiazepine agonist effects. To evaluate the specificity of these eye movement effects for agents acting at the central GABA-benzodiazepine receptor complex and the role of sedation in benzodiazepine effects, we studied eye movement effects of diphenhydramine, a sedating drug which does not act at the GABA-benzodiazepine receptor complex. Ten healthy males, aged 19-28 years, with no history of axis I psychiatric disorders or substance abuse, received 50 mg/70 kg intravenous diphenhydramine or a similar volume of saline on separate days 1 week apart. SEV, saccade latency and accuracy, SP, self-rated sedation, and short-term memory were assessed at baseline and at 5, 15, 30, 45, 60, 90 and 120 min after drug administration. Compared with placebo, diphenhydramine produced significant SEV slowing, and increases in saccade latency and self-rated sedation. There was no significant effect of diphenhydramine on smooth pursuit gain, saccade accuracy, or short-term memory. These results suggest that, like diazepam, diphenhydramine causes sedation, SEV slowing, and an increase in saccade latency. Since the degree of diphenhydramine-induced sedation was not correlated with changes in SEV or saccade latency, slowing of saccadic eye movements is unlikely to be attributable to sedation alone. Unlike diazepam, diphenhydramine does not impair smooth pursuit gain, saccadic accuracy, or memory. Different neurotransmitter systems may influence the neural pathways involved in SEV and smooth pursuit again.

Suicide attempt history in depressed patients with and without a history of panic attacks

This study of 346 depressed outpatients found a significant difference in the frequency of suicide attempts in those with a history of panic attacks (26.9%) compared with those without (16.8%). Further investigation showed that depressed patients with a history of infrequent panic attacks had a higher incidence of suicide attempts (32.3%) than those with panic disorder (21.5%). However, multiple regression analysis including a number of sociodemographic and diagnostic variables revealed that female gender and history of psychosis (but not panic attack history) significantly contributed to the variance in the history of suicide attempts. These data for depressed patients are compared with data from other studies regarding the association of panic attacks and suicidal behavior.

Eye movement effects of diazepam in sons of alcoholic fathers and male control subjects

Both animal and human studies suggest that the GABA-benzodiazepine receptor complex may be involved in the acute effects of ethanol, as well as the development of tolerance and dependence with chronic ethanol use. The current study was performed to assess sensitivity to benzodiazepines, and thus the functional sensitivity of the GABA-benzodiazepine receptor system, in subjects at high risk for alcoholism. Sons of alcoholic fathers (SOAs; n = 27) were compared with male controls without a family history of alcoholism (n = 23) in response to diazepam versus placebo. SOAs and controls received four logarithmically increasing doses of intravenous diazepam or placebo in randomized order on 2 days at least 1 week apart. Effects of diazepam were assessed using two eye movement tasks, peak saccadic eye movement velocity, and average smooth pursuit eye movement gain, which provide reliable, quantitative measures of benzodiazepine effects. In addition, memory, self-rated sedation, and pleasurable drug effects were measured. In comparison with control subjects, SOAs displayed significantly less diazepam effects on peak saccade velocity, average smooth pursuit gain, memory, and self-rated sedation, but significantly greater pleasurable drug effects. Differences in response to diazepam between SOAs and male controls may reflect altered functional sensitivity of the central GABA-benzodiazepine receptor system or a more general difference between groups in the effects of CNS active or sedating drugs.

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.

Personality and benzodiazepine sensitivity in anxious patients and control subjects

Cloninger has recently proposed a model of personality variability that is based on three independent heritable traits of harm avoidance, novelty seeking, and reward dependence, each of which is thought to be mediated by a separate neurochemical and neuroanatomic mechanism. The current study tested hypotheses generated on the basis of this theory in anxious patients and control subjects. Eighteen patients with panic disorder, 12 patients with generalized anxiety disorder, and 21 control subjects underwent both personality testing and assessment of their sensitivity to diazepam, as measured by slowing of saccadic eye movement velocity. As expected, anxious patients displayed higher harm avoidance scores than controls. Although an inverse correlation between harm avoidance and benzodiazepine sensitivity was predicted, no relationship between these variables was found in any diagnostic group. However, a significant correlation was found between novelty-seeking scores and sensitivity to diazepam. This finding, although not predicted by Cloninger's theory, is consistent with prior preclinical and human studies.

DSM-III-R personality disorders in a mood and anxiety disorders clinic: prevalence, comorbidity, and clinical correlates

This study examined the prevalence, comorbidity, and clinical correlates of personality disorders in an outpatient sample (N = 352) with anxiety and depression. Subjects were diagnosed using the Structured Clinical Interview for DSM-III-R (SCID) on Axes I and II, and they also completed interview and self-report measures of symptoms. Subjects with a personality disorder were less likely to be married, more likely to be single or divorced, had lower family incomes, had more severe symptoms of both anxiety and depression, and had a greater number of lifetime Axis I diagnoses. Subjects with dysthymic and bipolar disorders were more likely, and subjects with panic disorder uncomplicated by agoraphobia were less likely to have a personality disorder compared to the rest of the sample. The most prevalent personality disorders were Avoidant, Obsessive-Compulsive, Paranoid, and Borderline. Paranoid co-occurred with Narcissistic, and Borderline co-occurred with Histrionic personality disorder significantly more often than chance and base rates would predict.

Benzodiazepine pharmacodynamics: utility of eye movement measures

The utility of several measures of saccadic and smooth pursuit eye movements as benzodiazepine pharmacodynamic measures was explored in 24 psychiatrically and medically health control subjects. Measures of sedation and memory impairment were also included. Subjects received four logarithmically increasing doses of intravenous diazepam at 15-min intervals on 1 day resulting in monotonically increasing plasma diazepam levels, and placebo on another day in random order 1 week apart. Measures were collected twice at baseline, once after each dose of diazepam/placebo and twice more, 15 and 30 min after the last dose. Peak saccadic velocity and smooth pursuit gain showed the greatest overall and dose-dependent drug effect among eye movement measures. Although effect sizes at the highest dose for memory impairment and self-rated sedation were comparable to these two measures, reliability (i.e., placebo-day fluctuation) with these measures was considerably poorer. Log-linear pharmacodynamic modeling was used to calculate the effective dose (ED30) or concentration (EC30) required to reduce saccadic velocity or pursuit gain by 30%. Almost all (23/24) subjects had linear and easily interpretable plots for saccadic velocity, while a majority (19/24) of subjects had interpretable plots for smooth pursuit gain. The distribution of ED30 and EC30 values showed a wide range of sensitivities to diazepam. These findings suggest that saccadic velocity and smooth pursuit gain are sensitive, reliable, quantitative benzodiazepine pharmacodynamic measures.

Adjunctive treatment of benzodiazepine discontinuation syndromes: a review

The variety of pharmacologic and psychotherapeutic approaches to facilitate benzodiazepine discontinuation are reviewed. Strategies to attenuate physiologic withdrawal with clonidine, propranolol and carbamazepine have been inconsistently effective. Strategies to prevent relapse by substituting medications that could later be discontinued more easily (i.e., antidepressants and azapirones) appear more useful but have been less well studied. Psychotherapeutic approaches appear to work, but specific therapeutic components are unclear and non-specific "placebo" effects may play an important role.

Response to diazepam in sons of alcoholics

Alcohol exerts several of its actions via the chloride channel associated with the central GABA-benzodiazepine receptor complex. To explore a possible role for this receptor complex in risk for alcoholism, and to determine whether risk for alcoholism is associated with risk for benzodiazepine abuse, the authors administered intravenous diazepam to 18 sons of male alcoholics (SOAs) and 18 control subjects. Four logarithmically increasing doses of diazepam and matched volumes of placebo were given in randomized order on separate days about 1 week apart. SOAs were significantly more likely than controls to report euphoric responses to diazepam. At some diazepam doses, SOAs were more likely to report feeling "high" and "intoxicated." SOAs and controls did not differ in feeling "drugged." SOAs and controls may differ in expectations regarding the subjective effects of drugs and/or in the function of the central GABA-benzodiazepine receptor complex. These findings also add further evidence for increased pleasurable effects, and thus possibly increased risk for benzodiazepine abuse, in a subgroup of SOAs.

The relationship between anxiety and depression: a clinical comparison of generalized anxiety disorder, dysthymic disorder, panic disorder, and major depressive disorder

This study examined the relationship between the chronic disorders, generalized anxiety disorder (GAD) and dysthymic disorder (DD), and the more acute disorders, panic disorder (PD) and major depressive disorder (MDD) in 110 psychiatric outpatients with diagnoses of either PD, MDD, GAD, or DD. Pure, mixed, and early-/late-onset forms of the chronic disorders were compared with each other and then with PD and MDD on clinical measures and psychiatric history. Minimal differences were found between pure GAD and mixed GAD or between pure DD and mixed DD. The chronic disorders, DD and GAD, had distinct clinical symptom profiles when compared with each other and appeared more closely related to their parent disorders than to each other. However, despite these similarities, there were significant differences between DD and MDD in contrast to the minimal differences between GAD and PD, providing less support for GAD as a valid diagnostic category separate from PD. Comparisons of early-/late-onset DD and GAD showed more severe symptoms in late-onset DD, in contrast to more severe symptoms in early-onset GAD. These varying patterns of symptom severity may warrant study for further syndromal delineation.

Coping in panic and major depressive disorder. Relative effects of symptom severity and diagnostic comorbidity

This study used the Ways of Coping Checklist to examine coping style in patients with panic and major depressive disorders. The relative contribution of distress (symptom severity) and diagnostic comorbidity was determined in three sets of diagnostic subgroups: patients suffering from both panic and major depressive disorders (compared with either disorder alone); panic patients with and without agoraphobia (regardless of concurrent depression); and patients with versus without a concurrent axis II personality disorder. Use of less problem-focused and more emotion-focused coping was strongly correlated with level of distress and was associated with all three examples of diagnostic comorbidity when level of distress was used as a covariate. Regression analyses showed that, except for the presence of a personality disorder, distress was a much stronger predictor of coping than diagnostic subtype.

Alcohol abuse, substance abuse, and panic disorder

The purpose of this article is to review the literature concerning the interaction of alcohol and/or substance abuse with panic disorder, the comorbidity of these disorders, possible causal relationships, biologic relationships, and the recognition and treatment of dually disordered patients. A number of studies suggest significant comorbidity between panic disorder and alcoholism or abuse of drugs, especially cocaine and sedatives. Panic may lead to drinking or sedative use and also result from prolonged use or withdrawal of alcohol or other drugs. Possible biologic relationships involve the gamma-aminobutyric acid (GABA)-benzodiazepine receptor complex and the central noradrenergic system. Although treatment of panic in substance abusers has not been studied specifically, guidelines for recognition and management of these patients, including use of antipanic medication, are discussed.

Effect of acute and chronic benzodiazepines on plasma GABA in anxious patients and controls

The acute effects of diazepam on plasma GABA were determined in 18 patients with panic disorder, 13 patients with generalized anxiety disorder and 20 healthy controls. All subjects were benzodiazepine-naive. Four logarithmically increasing doses of diazepam/placebo were administered intravenously at 15-min intervals on 2 separate days. Plasma GABA was measured at baseline and 3 min after the highest dose of diazepam/placebo. There was an overall decrease in plasma GABA that was significantly greater following diazepam compared with placebo, but no group differences in response. In a separate group of 18 panic disorder patients receiving chronic benzodiazepine treatment with alprazolam, the same diazepam infusion procedure (no placebo day) produced decreases in plasma GABA similar to those seen in the untreated panic disorder patients. The clinical and physiologic implications of these findings are discussed.

Neuroendocrine effects of diazepam in panic and generalized anxiety disorders

The adrenocorticotropic hormone (ACTH), cortisol, and growth hormone responses to four consecutive, logarithmically increasing doses of intravenous diazepam compared with placebo given at 15-min intervals were examined in patients with panic disorder (n = 13), generalized anxiety disorder (n = 8), and healthy controls (n = 13). Diazepam caused dose-dependent decreases in cortisol and increases in GH and dose-independent decreases in ACTH. There were no patient-control differences, possibly due to either the small sample size of the experimental paradigm, which tested subjects in an upright, sitting position in mildly arousing circumstances.

Lactate vulnerability after alprazolam versus placebo treatment of panic disorder

Thirty-six patients with panic disorder underwent sodium lactate infusion before and after 8 weeks of treatment with alprazolam or placebo. With reinfusion, those patients panic-free with chronic alprazolam treatment displayed significantly decreased reactivity to lactate, as measured by subjective symptom ratings, duration of infusion before developing peak lactate-induced symptoms, and the proportion of patients experiencing lactate-induced anxiety or panic. Patients panic-free on placebo, as well as nonresponders to alprazolam treatment, displayed some, although less striking, decreases in reactivity to lactate with reinfusion. As a group, patients clinically unchanged with placebo treatment showed no systematic change in lactate response with reinfusion. Although the small numbers of patients in each treatment outcome group prohibit drawing definitive conclusions, these findings suggest that decreases in lactate-induced panic after successful alprazolam treatment of panic may result from a combination of changes in clinical state and direct effects of the medication.

The use of benzodiazepines in the workplace

Benzodiazepines differ from many of the other abused substances in that there are legitimate medical indications for their use. Any prescription for benzodiazepines must be preceded by a careful risk-benefit analysis that considers the specifics of an individual's particular life situation, personality style, and psychiatric diagnosis. The risk of benzodiazepine abuse by chemically dependent individuals and the problems of cognitive and/or psychomotor impairment and dependence for all individuals have to be balanced against the therapeutic benefits of these drugs for patients who experience disabling anxiety disorders or anxiety that accompanies chronic medical illness. Problems of dependence can be minimized by utilizing a variety of pharmacologic and psychotherapeutic strategies to ameliorate withdrawal symptoms that might accompany the discontinuation of long-term benzodiazepine treatment.

Reduced benzodiazepine sensitivity in panic disorder

We evaluated the functional sensitivity of the gamma-aminobutyric acid-benzodiazepine supramolecular complex in 9 patients with panic disorder and 10 psychiatrically healthy control subjects by comparing the effects of four logarithmically increasing doses of intravenous diazepam on saccadic eye movement velocity, memory, and self-rated sedation. Patients with panic disorder were less sensitive than controls to diazepam using eye velocity as the dependent measure. Sedation and memory effects did not distinguish the two groups. These findings suggest that panic disorder is associated with functional subsensitivity of the gamma-aminobutyric acid-benzodiazepine supramolecular complex in brain-stem areas controlling saccadic eye movements.

Drug preferences of alcoholic polydrug abusers with and without panic

Manifestations of anxiety, including panic disorder, are more common in the alcoholic population than in the general population. Alcoholics frequently abuse other drugs. The authors hypothesized that alcoholic subjects with panic attacks would abuse anxiolytic drugs more and panic-inducing drugs less frequently than nonanxious alcoholic subjects, and that their abuse of panic-inducing drugs would predate the age at panic onset. Findings indicate that alcoholic subjects with panic attacks (but not panic disorder) abused opiates and sedatives to a greater degree than nonanxious alcoholic subjects and abused marijuana, a panic-inducing drug, at a younger age. More alcoholic subjects with panic disorder than with panic attacks abused cocaine. The prevalence of abuse and the ages at onset of abuse of other drugs were similar for both the panic and the nonpanic group.

The diagnostic utility of lactate sensitivity in panic disorder

Lactate infusion is the most extensively studied of the pharmacological challenge tests in panic disorder. We assessed the value of this test in the diagnosis and subtyping of panic in clinical and research settings. Analysis of lactate infusion studies to date suggests that patients with panic attacks are significantly more sensitive to lactate than are healthy controls or patients with other psychiatric disorders without panic attacks. However, the usefulness of lactate infusion is limited by the lack of standardized, objective criteria for lactate-induced panic and uncertainty as to the sensitivity and specificity of the test for current, clinically significant panic attacks. Except in rare cases, the clinical history is likely to be of more value than lactate response in diagnosing panic disorder. Determination of the role of the test in subtyping patients with panic disorder awaits further study of the diagnostic, prognostic, genetic, and pathophysiologic significance of lactate sensitivity.

Response to sodium lactate infusion in alcoholics with panic attacks

The authors studied the response to sodium lactate infusion of 12 alcoholics with a history of panic attacks, 10 alcoholics without a history of panic attacks, and 16 nonalcoholic patients with panic disorder. The rate of lactate-induced panic was significantly higher in alcoholics with panic attacks than in alcoholics without panic attacks. Alcoholics with panic attacks were similar to nonalcoholic patients with panic disorder in their response to lactate. These findings support the specificity of lactate-induced panic for panic states and suggest that panic attacks in alcoholics resemble those in nonalcoholics. Lactate infusion may prove useful in the diagnosis of panic disorder in alcoholics.

Prevalence, onset, and clinical recognition of panic states in hospitalized male alcoholics

Alcoholism has been associated with a high prevalence of anxiety and phobic disorders. The authors ascertained the current prevalence of panic disorder and the lifetime prevalence of infrequent panic attacks in 154 male alcoholics in an inpatient alcohol treatment program. Thirteen percent (N = 20) gave a lifetime history of panic attacks and 45% (N = 9) of these had current panic disorder. Panic attacks preceded or coincided with the onset of problem drinking in 50% (N = 9) of the 18 patients with both diagnoses. Only two patients with histories of panic had been previously diagnosed, and none had been treated. Clinical implications of these findings are discussed.

Relapse and rebound following discontinuation of benzodiazepine treatment of panic attacks: alprazolam versus diazepam

The authors assessed the effects of partial tapering followed by abrupt discontinuation of alprazolam, diazepam, and placebo in 40 patients with panic attacks. The anxiety scores and frequency of panic attacks of the three groups did not differ at the end of the initial 2-week taper, but 1 week after abrupt discontinuation of the remaining medication, patients formerly taking alprazolam had greater increases in anxiety but no more panic attacks than did the other patients. Because of low statistical power, differences in benzodiazepine half-lives, absence of multiple ratings, and imbalances between groups in clinical characteristics, these findings must be viewed as preliminary.

Response to sodium lactate in panic disorder: relationship to presenting clinical variables

Sodium lactate infusion provokes more physiological and psychological symptoms of panic in patients with panic attacks than in normal controls. The relationship between response to sodium lactate infusion and presenting clinical characteristics was examined in 50 patients with panic disorder or agoraphobia with panic attacks. Lactate-induced panic was significantly related only to a patient-reported family history of panic. Rating of physical symptoms during lactate infusion, but not overall response to lactate, was significantly correlated with Symptom Checklist-90 somatization scores. In general, lactate response does not identify clinically distinct subpopulations of patients with panic disorder.

Response to lactate infusion in generalized anxiety disorder

Intravenous sodium lactate infusion provokes symptoms of panic in patients with panic disorder at a significantly higher rate than in normal controls. Lactate sensitivity has been postulated to be specific for patients with panic attacks regardless of frequency of attacks or coexisting diagnoses. The authors present results of a pilot study of lactate infusions in patients with generalized anxiety disorder (GAD) without any history of panic attacks. Patients with GAD reacted more like panic disorder patients than like normal controls in anxiety and symptom scores during lactate infusion and in the rate of positive responses to lactate. Although preliminary, these findings raise questions regarding the specificity of lactate sensitivity and the relationship of GAD to panic disorder.

Hyperventilation and panic disorder

Hyperventilation syndrome and panic disorder are both common, serious, and easily treatable disorders. The similarity of their symptoms and physiology, the demonstration of hyperventilation during spontaneous and laboratory-induced panic episodes, provocation of panic-like symptoms in some patients with panic disorder using hyperventilation, the importance of psychologic factors in producing hyperventilation, and successful treatment of panic disorder with breathing retraining all indicate a strong association between these two conditions. About 50 percent of patients in each group show evidence of both disorders. It is suggested that many patients in each group show evidence of both disorders. It is suggested that many patients with either diagnosis have the same disorder and share a biologically and often genetically determined hypersensitivity of a central "alarm" system. Panic and hyperventilation provoked by inappropriate activation of this system are postulated to reinforce each other by a positive feedback loop. Treatments directed at any part of this loop are likely to be successful. Clinical implications of the link between these conditions are discussed.