Venlafaxine extended-release capsules in panic disorder: flexible-dose, double-blind, placebo-controlled study

BACKGROUND

Venlafaxine extended-release (ER) has proven efficacy in the treatment of anxiety symptoms in major depression, generalised anxiety disorder and social anxiety disorder.

AIMS

To evaluate the efficacy, safety and tolerability of venlafaxine ER in treating panic disorder.

METHOD

Adult out-patients (n=361) with panic disorder were randomly assigned to receive venlafaxine ER (75-225 mg/day) or placebo for up to 10 weeks in a double-blind study.

RESULTS

Venlafaxine ER was not associated with a greater proportion of patients free from full-symptom panic attacks at the final on-therapy evaluation, but was associated with lower mean panic attack frequency and a higher proportion free from limited-symptom panic attacks, higher response and remission rates, and improvements in anticipatory anxiety, fear and avoidance. Adverse events were comparable with those of the drug in depression and anxiety disorders.

CONCLUSIONS

Venlafaxine ER seems to be effective and well tolerated in the short-term treatment of panic disorder.

Peripheral-type benzodiazepine receptor binding sites in platelets of patients with panic disorder associated to separation anxiety symptoms

RATIONALE

Although it is still a matter of debate whether panic disorder (PD) and separation anxiety (SA) are associated or causally linked disorders, some investigators have suggested that SA may be a specific subtype of panic-agoraphobic spectrum. Several psychiatric disorders, including PD, are associated with lower levels of peripheral-type benzodiazepine receptor (PBR).

OBJECTIVES

The aim of the present study was to evaluate the kinetic binding parameters of the specific PBR ligand, PK 11195, in platelets from patients with PD in relation to the presence and severity of adulthood SA.

METHODS

Using the specific radioligand, [(3)H] PK 11195, the kinetic binding parameters of PBR were determined on platelet membranes of 27 adult outpatients with a DSM-IV diagnosis of PD and 18 healthy controls. Patients were assessed with the SCID-I, the Panic Disorder Severity Scale, the Structured Clinical Interview for Separation Anxiety Symptoms and the Adult Separation Anxiety Checklist.

RESULTS

PD patients had significantly lower PBR density than controls. However, the lower density was only evident in the subgroup of PD patients who also fulfilled the DSM-IV criteria for adult separation anxiety disorder. PBR density was negatively correlated with each of the two SA scales total scores.

CONCLUSIONS

Patients with SA symptoms had significantly lower densities of PBRs. PBR expression might become a useful biological marker of these two associated conditions.

Plasma concentrations of anxiolytic neuroactive steroids in men with panic disorder

Plasma concentrations of neuroactive steroids in men with panic disorder (PD) were measured to evaluate their relations to psychopathology both before and during treatment. Participants comprised 13 men with PD and 10 normal controls. Patients were evaluated while drug-free as well as after 1 and 2 months of paroxetine therapy. Psychopathology was assessed by the State-Trait Anxiety Inventory (STAI), the Panic-Associated Symptom Scale, and the Fear Questionnaire total score. Plasma concentrations of steroids were measured by radioimmunoassay. The plasma concentrations of progesterone and dehydroepiandrosterone were greater in drug-free patients than in controls, whereas those of allopregnanolone and tetrahydrodeoxycorticosterone did not differ between the two groups. Paroxetine treatment for 2 months significantly increased the plasma concentration of allopregnanolone but did not affect those of the other steroids. At 2 months of therapy, allopregnanolone concentrations in patients were significantly greater than those in controls. The plasma concentrations of progesterone and tetrahydrodeoxycorticosterone correlated with the STAI state score in patients before treatment. Our data suggest that neuroactive steroids may play a role in PD in men.

Cognitive Modulation of the Endocrine Stress Response to a Pharmacological Challenge in Normal and Panic Disorder Subjects

CONTEXT

The hypothalamic-pituitary-adrenal (HPA) axis may mediate the deleterious effects of stress on health. It is sensitive to cognitive and emotional aspects of organism-environment interactions, such as familiarity, control, and social support. Scientific study of how such factors moderate human HPA axis activity has been limited. Their relevance to HPA axis disturbances in psychiatric patients is largely unexplored.

OBJECTIVE

To determine whether cognitive manipulation can alter HPA axis activity in laboratory studies and whether patients with panic disorder are differentially sensitive to the manipulated factors.

DESIGN

Pharmacological activation paradigm (cholecystokinin-B agonist pentagastrin) by which we examined symptom and endocrine effects on subjects randomly assigned to a standard introduction or a cognitive intervention.

SETTING

Clinical research center.

PARTICIPANTS

Recruited from university clinic and newspaper advertisements. Fourteen patients with panic disorder and 14 controls, individually matched for age and sex. Intervention Half of each group received a 9-minute cognitive intervention designed to reduce novelty, increase cognitive coping, and provide a sense of control.

MAIN OUTCOME MEASURES

Corticotropin (ACTH) and cortisol levels.

RESULTS

The cognitive intervention significantly reduced cortisol (P = .02) and ACTH (P = .01) levels, despite pentagastrin's robust stimulation of both hormones (P<.001). The intervention effect was evident in patients and controls, who did not differ in basal HPA axis activity or response to pentagastrin. They did differ in panic symptom responses, which were unaffected by the intervention, and in ACTH effects of the intervention. Patients' exaggerated anxiety responses to pentagastrin were normalized by the intervention.

CONCLUSIONS

Cognitive/emotional manipulation can substantially modulate HPA axis responses to pharmacological activation in humans, and HPA disturbances in panic disorder may be secondary to manipulable cognitive/emotional sensitivities. Further study of such factors as novelty, control, and coping may help clarify the origins of HPA axis disturbance in psychiatric disorders and the mediators linking psychosocial stress to disease.

No association of the brain-derived neurotrophic factor (BDNF) gene polymorphisms with panic disorder

Several lines of evidence suggest that genetic factors might contribute to susceptibility to panic disorder. Our previous studies show that the brain-derived neurotrophic factor (BDNF) may play a role in the pathophysiology of major depressive disorders and eating disorders. Assuming that BDNF may be implicated in the putative common pathophysiology of depression and anxiety, we analyzed the association of two BDNF gene single nucleotide polymorphisms (SNPs), 132C > T (formerly named C270T) in the noncoding region of exon V and 196G > A (val66met) in the coding region of exon XIIIA, with panic disorder. In this study, 109 patients with panic disorder diagnosed according to the DSM-IV criteria, and 178 control subjects were recruited. There were no significant differences in the frequency of the genotype or allele in these two SNPs between patients and controls [132C > T in exon V: genotype, p = 1.0, allele, p = 0.59; 196G > A (val66met) in exon XIIIA: genotype, p = 0.77, allele, p = 0.78]. Furthermore, no significant associations of agoraphobia with the two SNPs were detected. This study suggests that the BDNF gene polymorphisms are not associated with panic disorder in our Japanese population.

Twenty-four hour growth hormone secretion in patients with panic disorder

BACKGROUND

Patients with panic disorder have blunted growth hormone (GH) responses to clonidine, suggesting subsensitivity of post-synaptic alpha(2)-adrenoreceptors, presumably in response to excessive central noradrenergic outflow. However, basal levels of GH release over a full circadian cycle have not been examined in panic. Reduced basal GH release would suggest an overall hypo-active GH system rather than a specific alpha-adrenergic abnormality.

METHODS

To determine whether panic patients show reduced basal GH secretion, 20 patients and 12 healthy controls were studied. Blood samples were drawn every 15 min for 24 h and plasma was assayed for GH. Patients were restudied during successful treatment with alprazolam. Groups were compared on overnight and daytime GH secretion and circadian patterns of release.

RESULTS

Patients showed normal levels on all measures of GH release. Treatment may have reduced nocturnal GH release slightly, but treated patients still did not differ from controls. The normal predominance of sleep over waking GH secretion was seen in both groups.

CONCLUSIONS

Panic patients, in contrast to depressed patients, have normal somatotrophic axis activity when measured in a resting state over a full circadian cycle. GH dysregulation may only be evident in these patients in activation paradigms and has been most consistently demonstrated by challenges with the alpha(2)-noradrenergic agonist, clonidine.

Metyrapone tests in patients with panic disorder

BACKGROUND

Studies of hypothalamic secretion of corticotropin-releasing hormone (CRH) in patients with panic disorder in the nonpanic state (using CRH tests) are contradictory. No data about the hypothalamic-pituitary response to metyrapone are available.

METHODS

Study participants included 14 patients with panic disorder (DSM-IV criteria) and 14 healthy control subjects who underwent a standard overnight metyrapone test and a combined metyrapone/low-dose dexamethasone test.

RESULTS

Significant treatment effects of metyrapone and combined metyrapone/dexamethasone were found on plasma corticotropin, cortisol, and 11-deoxycortisol, but no differences between patients and control subjects emerged. Considering visual analogue scale ratings of anxiety, tension, restlessness, and Beck Depression Inventory scores as covariates, no group effects were detected.

CONCLUSIONS

Standard overnight metyrapone tests do not support a hypersecretion of hypothalamic CRH in panic disorder. Furthermore, no evidence for increased glucocorticoid negative feedback in panic was found. Hypothalamic CRH secretion in the nonpanic state needs further research.

Serotonin-mediated phosphorylation of extracellular regulated kinases in platelets of patients with panic disorder versus controls

Phosphorylation of extracellular signal-regulated kinases (ERK 1/2) represents a converging intracellular signalling pathway which is involved in the modulation of gene transcription and may contribute to the feed-back regulation of neurotransmitter receptor functioning. The purpose of the current study was to investigate the serotonin-mediated phosphorylation of ERK 1/2 in platelets from patients (n = 17) with panic disorder, with respect to healthy volunteers (n = 17). Patients presented a severe symptomatology as assessed by the self-report rating scales for panic-agoraphobic (PAS-SR) and mood (MOOD-SR) spectrum, and by Clinical Global Impression Severity Scale (CGI-S). In platelets from healthy volunteers, serotonin induced a rapid increase of ERK 1/2 phosphorylation with a transient monophasic kinetic. The dose-response curves showed this effect was concentration dependent with an average of the EC(50) value of 22.8 +/- 2.4 microM. Platelet pre-incubation with 5HT(1A) and 5HT(2A) antagonists, pindobind and ritanserin, significantly inhibited serotonin-mediated kinase activation with an EC(50) of 3.2 +/- 0.2 and 1.99 +/- 0.08 nM, respectively, suggesting an involvement of these specific receptor subtypes in serotonin-mediated response. Furthermore, the 5HT(1A) and 5HT(2A) agonists, 8-hydroxy-N,N-dipropyl-aminotetralin (8OH-DPAT) and 1-(2,5-dimethoxy)-4-iodophenyl-2-aminopropane (DOI), were able to modulate ERK 1/2 phosphorylation in a concentration-dependent manner with an EC(50) value of 3.1 +/- 0.2 and 76 +/- 4.5 nM, respectively. ERK 1/2 phosphorylation was not observed after serotonin treatment of platelets from drug-free panic disorder patients, suggesting an alteration in intracellular phosphorylative pathways. Since ERK 1/2 responsiveness to other stimulus, such as collagen and thrombin, was comparable in platelets from healthy volunteers and patients, our results suggested that a specific alteration of serotonergic system occurred in panic disorder. Further studies to investigate 5HT(1A) and 5HT(2A) receptor expression and threonine phosphorylation levels showed that, nevertheless no significant differences in the receptor expression levels were detected, an increase of both 5HT receptor phosphorylation, on threonine residues, occurred in platelet from panic patients with respect to controls, suggesting that a reduction of serotonin receptor functioning was involved in the loss of serotonin responsiveness in panic.

Serum lipid levels, suicidality, and panic disorder

Although the effects of serum total cholesterol and other lipids have been implicated as a predictor of suicidal behavior in major depression, the role of cholesterol level on suicide risk for panic disorder patients is not considered as a biological marker in the literature. In this study, we examined the relationship of suicidality with serum cholesterol concentration in panic disorder. The subjects of the study were 10 suicidal panic disorder patients, 19 nonsuicidal panic disorder patients, and 15 normal control subjects. The suicidal patients with panic disorder had lower serum total cholesterol and low-density lipoprotein (LDL) levels than normal control subjects. These findings suggest that there may be an association between suicidality and low serum cholesterol levels in panic disorder. We also discuss the possible role of serotonin in the brain in the relationship of suicidal behavior or ideation with low cholesterol concentration in panic disorder.

Effects of exposure to selective serotonin reuptake inhibitors during pregnancy on serotonergic symptoms in newborns and cord blood monoamine and prolactin concentrations

BACKGROUND

Selective serotonin reuptake inhibitors (SSRIs) have gained wide acceptance in the treatment of mental disorders in pregnant women, but there seems to be an increased risk for neonatal adaptation problems after exposure to SSRIs in late pregnancy. We aimed to investigate the perinatal sequelae of infants exposed to SSRIs during their fetal life and the relationship of these symptoms to the cord blood monoamine and prolactin concentrations.

METHODS

We conducted a prospective, controlled, follow-up study with 20 mothers taking 20 to 40 mg/d of either citalopram or fluoxetine for depression (n = 10) or panic disorder (n = 10) and their infants and 20 matched controls not receiving psychotropic medication for confounding obstetric characteristics. Maternal cord blood and infant citalopram, fluoxetine, and norfluoxetine, cord blood monoamine and metabolite, and prolactin concentrations were measured. The newborns underwent standard clinical examination and specific assessment of serotonergic symptoms during the first 4 days of life and at the ages of 2 weeks and 2 months.

RESULTS

There was a statistically significant (P =.008, V = 15, n = 20 for both groups), 4-fold difference in the serotonergic symptom score during the first 4 days of life between the SSRI group and the control group. The SSRI-exposed infants had significantly lower cord blood 5-hydroxyindoleacetic acid (5-HIAA) concentrations (P =.02, t31 = 2.57) compared with the control group. A significant inverse correlation (rs = -0.66, P =.007, n = 15) was seen between the serotonergic symptom score and the umbilical vein 5-HIAA concentrations in the SSRI-exposed but not the control infants.

CONCLUSIONS

Infants exposed to SSRIs during late pregnancy are at increased risk for serotonergic central nervous system adverse effects, and the severity of these symptoms is significantly related to cord blood 5-HIAA levels.

Neurosteroid secretion in panic disorder

Evidence that neurosteroids have anxiolytic effects in animal models of anxiety has suggested that alterations of neurosteroid secretion might be implicated in the pathogenetic mechanisms of anxiety disorders in humans. In 25 female patients with panic disorder (PD) and 11 healthy female controls, we measured plasma concentrations of progesterone (PROG), pregnenolone (PREG), allopregnanolone (3alpha,5alpha-tetrahydroprogesterone=3alpha,5alpha-THPROG), dehydroepiandrosterone (DHEA) and tetrahydrodeoxycorticosterone (3alpha,5alpha-THDOC) during a drug-free month and during the following month of paroxetine therapy. The neurosteroids were measured during the early follicular phase, the mid-luteal phase and the premenstrual phase of both months (days 7, 22 and 27 from the beginning of the cycle). Significantly higher levels in patients than controls were found in PROG during the mid-luteal phase of both months, PREG in the premenstrual phase in the drug-free month, 3alpha,5alpha-THPROG during the follicular phase of the drug-free month and during the premenstrual phase of the therapy month, and 3alpha,5alpha-THDOC during the premenstrual phases of both months. DHEA levels did not differ in patients and controls. These results suggest that neurosteroids in PD are hypersecreted, possibly as an attempt to counteract the anxiogenic underlying hyperactivity of the hypothalamo-pituitary-adrenal axis and to improve a reduced GABA(A) receptor sensitivity.

Antioxidant enzyme and malondialdehyde levels in patients with panic disorder

There is evidence of an etiopathogenetic role of free radicals (FRs) in some neuropsychiatric disorders. The aim of the present study was to determine whether the activity levels of some antioxidant enzymes [glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and catalase (CAT)] and malondialdehyde (MDA), a product of lipid peroxidation, were associated with panic disorder (PD). Twenty patients diagnosed with PD and 20 healthy controls were enrolled in this study. A clinical evaluation and measurements of GSH-Px SOD, CAT and MDA were performed. Additionally, all patients were assessed by the Panic Agoraphobia Scale (PAS). The mean GSH-Px, SOD and MDA levels of the patient group were significantly higher than those of the controls. There was a significant positive correlation between PAS scores and GSH-Px, SOD and MDA levels and between the duration of illness and SOD, CAT and MDA levels in the patient group. In conclusion, our results suggest that FRs may be involved in PD.

Sympathetic reactivity in agoraphobic patients with and without personality disorders

OBJECTIVE

To compare sympathetic activity in agoraphobic patients with and without personality disorders before and after 11 weeks inpatient treatment.

METHODS

Agoraphobic patients (n=38), 84% with panic disorder and 47% with personality disorders underwent cold pressure test (CPT), mental stress test (MST), and a specific anxiety test (SAT). Psychological assessments were done by the Bodily Sensations Questionnaire (BSQ), the Agoraphobic Cognitions Questionnaire (ACQ), Spielberger STAI-1 and -2, and a Stress Test Anxiety (STA) questionnaire. Sympathetic activity was measured by blood pressure, heart rate, epinephrine, and norepinephrine.

RESULTS

The sympathetic activity did not differ significantly between patient groups, and the reactivity to stress was very low. The sympathetic reactivity remained unchanged after treatment, whereas psychiatric symptoms decreased. Correlations between sympathetic activity and psychological distress were not significant.

CONCLUSION

Interpretation of bodily signals seems to be more important than the actual sympathetic activity in agoraphobic patients.

Stress regulates the lymphocyte homing receptor CD62L (L-selectin)

Based on a previous study showing that panic disorder patients had increased expression of na ve phenotype lymphocytes (CD45RA+ and CD62L+), increased plasma cortisol, as well as decreased interleukin-2 (IL-2) producion, we hypothesized that changes in the percentage of expression of these lymphocyte surface molecules could be related to the substances released by the hypothalamic-pituitary-adrenal (HPA) axis and possibly associated to panic disorder (cortisol, IL-2, serotonin and epinephrine). In order to study the altered expression, blood mononuclear cells of normal volunteers were stimulated with mitogen, in the presence of dexamethasone, IL-2, serotonin and epinephrin. CD62L is decreased by IL-2 in vitro. Serotonin and epinephrine did not promote changes in the expression of these surface molecules. The results of the ex vivo study are in agreement with a previous clinical study with panic patients. It could be suggested that stress is responsible for certain immunologic dysfunctions and new studies should be conducted.

Induced panic attacks shift gamma-aminobutyric acid type A receptor modulatory neuroactive steroid composition in patients with panic disorder: preliminary results

BACKGROUND

Certain metabolites of progesterone such as 3alpha,5alpha-tetrahydroprogesterone (3alpha,5alpha-THP; allopregnanolone) and 3alpha,5beta-THP (pregnanolone) are potent, positive allosteric modulators of gamma-aminobutyric acid type A receptors. Although animal studies suggest anxiolytic properties of these endogenous modulators of central nervous excitability, no clinical data indicate whether they are also involved in the pathophysiology of anxiety disorders and panic attacks.

METHODS

We quantified the concentrations of 3alpha,5alpha-THP, 3alpha,5beta-THP, the isomer 3beta,5alpha-THP, and their precursors in the plasma of 10 patients with panic disorder and matched control subjects during panic attacks induced by means of sodium lactate and cholecystokinin tetrapeptide administration, using a highly sensitive gas chromatography-mass spectrometry analysis.

RESULTS

Panic attacks induced by sodium lactate and cholecystokinin tetrapeptide in patients with panic disorder were accompanied by pronounced decreases in the concentrations of 3alpha,5alpha-THP and 3alpha,5beta-THP and a concomitant increase in the concentrations of the functional antagonistic isomer 3beta,5alpha-THP, findings that are compatible with a decreased gamma-aminobutyric acid-ergic tone. No changes in neuroactive steroid concentrations were observed after placebo administration in patients with panic disorder or after placebo, sodium lactate, or cholecystokinin tetrapeptide administration in controls.

CONCLUSIONS

The association between changes in plasma neuroactive steroid concentrations and experimentally induced panic attacks and the well-documented pharmacological properties of these compounds as gamma-aminobutyric acid type A receptor modulators suggest that neuroactive steroids may play a role in the pathophysiology of panic attacks in patients with panic disorder.

Pentagastrin-induced sleep panic attacks: panic in the absence of elevated baseline arousal

BACKGROUND

It has been suggested that pharmacological challenges that induce panic attacks are confounded by effects of environmental stress, elevated baseline arousal, and expectancy bias.

METHODS

To control for effects of arousal and cognition on the panicogenic effects of pentagastrin, pharmacological challenges were conducted during sleep in seven patients with panic disorder or social phobia. All patients had previously experienced pentagastrin-induced panic while awake. Infusions of normal saline and pentagastrin (0.6 microg/kg) were administered in fixed order and timed so that pentagastrin infusions took place during the transition from Stage 2 to Stage 3 sleep. Long intravenous lines were placed for remote blood sampling and subsequent analysis of plasma adrenocorticotropic hormone and cortisol. Measures of anxiety and panic were obtained at baseline and upon awakening after pharmacological challenge.

RESULTS

All seven subjects awoke within seconds following pentagastrin infusion. Four patients reported symptoms that met criteria for panic. Neither baseline anxiety nor neuroendocrine measures were predictive of panic.

CONCLUSIONS

These data demonstrate the ability to induce panic during a period of diminishing arousal and indicate that panic attacks can occur in the absence of elevated arousal and environmental stress.

The protein kinase A in platelets from patients with panic disorder

Although previous studies suggested that dysfunctions in the protein kinase A (PKA) and in some of its substrates are associated with several psychiatric disorders, there is no evidence regarding the possible involvement of such components in panic disorder (PD). Thus, the aim of the present study was to investigate the levels of PKA and Rap1 in platelets from patients with such disorder. Twenty-four drug free patients with PD and 24 healthy volunteers participated to the study. Employing the Western Blot analysis, immunostaining and computer-assisted imaging, the levels of the regulatory (R, type I and type II) and the catalytic (C) subunits of PKA, and those of Rap1 were assessed in platelets from the two groups. The data show that patients with PD have significantly higher levels of platelet RI and C subunits of PKA than controls, whereas the levels of RII were unchanged. No significant differences were found in the immunolabelling of Rap1 between groups. These findings may provide clues toward understanding the involvement of cAMP signalling in anxiety disorders.

Aging and panicogenic response to cholecystokinin tetrapeptide: an examination of the cholecystokinin system

Older age is associated with diminished symptomatic and cardiovascular response to the panicogenic agent cholecystokinin tetrapeptide (CCK-4). We hypothesized that circulating concentrations of endogenous CCK-4 and/or CCK-8 are increased in later life, possibly due to decreased enzymatic degradation, and that this is associated with desensitization of CCK-B receptors. The study group consisted of 20 healthy subjects aged 18-30 years and 20 healthy subjects aged 65-85 years. The two groups were compared on fasting basal plasma concentrations of CCK-4, sulfated CCK-8 (CCK-8s) and nonsulfated CCK-8 (CCK-8 ns), and on binding capacity of lymphocyte CCK-B receptors. Under single-blind (to subject) conditions, subjects were then administered an intravenous bolus of placebo, followed 50 min later by an intravenous bolus of 50 micro g of CCK-4. Plasma concentrations of total CCK (CCK(T)) were measured 2 min before and 2, 5, 10, and 15 min after each injection. Compared with younger subjects, older subjects had a significantly higher basal plasma concentration of CCK-8s and significantly diminished binding capacity of CCK-B receptors. Following injection of placebo, plasma CCK(T) concentrations did not significantly change from baseline in either age group, but the elderly had significantly higher concentrations than the young at 2, 5, and 10 min. Following injection of CCK-4, the plasma concentration of CCK(T) was highest at 2 min and declined after that. The elderly had significantly higher CCK(T) concentrations (ie. a slower decline in CCK(T)) than the young at 5, 10, and 15 min. These findings are consistent with our hypothesis and suggest that age-related changes in the CCK system could contribute to the diminished panicogenic response to exogenous CCK-4 in older persons.

Memory performance in panic disorder patients after chronic use of clomipramine

This study investigated the chronic use (6.3 +/- 0.5 years; mean +/- SEM) of therapeutic doses of clomipramine (57.0 +/- 8.0 mg/day) by outpatients with panic disorder/agoraphobia who were currently in remission to assess impairment of memory and psychomotor functions. In addition, the association between test performance and serum levels of clomipramine (CMI) and its active metabolite desmethylclomipramine (DCMI) was also assessed. Patients and healthy volunteers matched for sex, age and educational level were submitted to rating scales and to memory and psychomotor tests. There was no significant difference between groups regarding any variable, except for metamemory. Significant associations were found between (i) longer-term clomipramine treatment and poorer performance in the implicit test and (ii) higher serum levels of clomipramine or desmethylclomipramine, or both (CMI + DCMI) and lower performance in central executive tests and metamemory. The results showed that low doses of CMI chronically administered to panic patients are associated with diminished metamemory and impaired priming and working memory. Further investigations are needed to confirm these results and to determine whether the chronic use of higher therapeutic doses of tricyclic antidepressants is associated with more intense deleterious effects on memory and psychomotor functions.

Effect of citalopram treatment on relationship between platelet serotonin functions and the Karolinska scales of personality in panic patients

Using the Karolinska Scales of Personality (KSP), we investigated the effect of the selective serotonin reuptake inhibitor citalopram on personality traits and the relationship between personality traits and peripheral indexes for central serotonergic function in patients with panic disorder at baseline and after 6 months of treatment. The degree of anxiety and depression was assessed using the Beck Anxiety Inventory, the Beck Depression Inventory, the Clinical Anxiety Scale, and the Montgomery Asberg Depression Rating Scale. A reduction in anxiety and depression scores of 75% was observed after treatment in two thirds of the patients. Mean changes of 12% in the direction of normalization were observed in all KSP anxiety-related items (Somatic Anxiety, Muscular Tension, Psychic Anxiety, and Psychasthenia), the aggression and hostility related items (Inhibition of Aggression, Irritability, and Guilt) and the item of Socialisation. A positive correlation was found between Vmax for the platelet [14C]-serotonin uptake and Inhibition of Aggression before treatment, and a negative correlation was found between the affinity of serotonin uptake and Inhibition of Aggression after treatment. Negative childhood experiences influenced enhanced scores on some KSP items but not the serotonergic function. In panic patients treated with citalopram, effects were seen on personality traits, confirming an association between serotonergic activity and aggression.

Serum cholesterol level comparison: control subjects, anxiety disorder patients, and obsessive-compulsive disorder patients

OBJECTIVE

To determine whether panic disorder is associated with elevated serum cholesterol levels. Serum cholesterol levels of panic disorder patients are reported to be elevated. This could explain the higher-than-expected cardiovascular mortality in this population. Some evidence exists wherein cholesterol levels are also increased in patients with general anxiety disorder and phobias. To date, there are only 2 reports on cholesterol levels of obsessive-compulsive disorder (OCD) patients, giving controversial results.

METHOD

We compared serum cholesterol levels of anxiety disorder patients, OCD patients, and normal control subjects with each other (n = 60 in each group). Serum cholesterol was measured in each subject before treatment. Subjects of the 3 groups were matched by age and sex.

RESULTS

Patients with anxiety disorders and OCD had elevated cholesterol levels, compared with normal control subjects. Cholesterol levels in OCD patients were comparable with those in patients with phobia.

CONCLUSIONS

Our data support the assumption that elevation in cholesterol level is not a specific feature of panic disorder (as most assumed), but more generally associated with anxiety disorders. Increased cholesterol levels in patients with anxiety disorders and OCD may be of clinical relevance.

Prolactin but not ACTH increases during sodium lactate-induced panic attacks

Paradoxically, the pituitary-adrenal axis is not activated during sodium lactate-induced panic. We measured the response of another stress-sensitive hormone, prolactin, to standard lactate and placebo infusion in a double-blind randomised design in eight patients with panic disorder and eight matched normal controls. Prolactin release was significantly elevated (P < 0.05) in panickers compared with non-panickers, whereas ACTH secretion was not activated at all. This differential stress response needs further investigation.