scholarly journals Effect of acute tryptophan depletion on CO2-induced anxiety in patients with panic disorder and normal volunteers

2000 ◽  
Vol 176 (2) ◽  
pp. 182-188 ◽  
Author(s):  
H. E. J. Miller ◽  
J. F. W. Deakin ◽  
I. M. Anderson
Keyword(s):  
Panic Disorder ◽  
Panic Attacks ◽  
Acute Tryptophan Depletion ◽  
Tryptophan Depletion ◽  
Double Blind ◽  
Normal Volunteers ◽  
Plasma Tryptophan ◽  
Drug Free ◽  
Normal Controls

BackgroundUncertainties remain about the role of serotonin in the aetiology and treatment of panic disorder.AimsTo investigate the effect of reducing brain serotonin function on anxiety at rest, and following 5% CO2 provocation in normal controls and patients with panic disorder.MethodTwenty drug-free patients with DSM–III–R panic disorder and 19 controls received a tryptophan-free amino acid drink on one occasion and a control drink on the other in a double-blind, balanced protocol. 5% CO2 was given as a panic challenge after 270 minutes.ResultsPlasma tryptophan fell by more than 80% both patients and controls after the tryptophan-free drink. Tryptophan depletion did not alter resting anxiety. In patients alone, tryptophan depletion caused a greater anxiogenic response and an increased rate of panic attacks (9 v. 2, P<0.05) after 5% CO2 challenge. No normal volunteers panicked.ConclusionsSerotonin may directly modulate panic anxiety in patients with panic disorder. This may underlie the efficacy of serotonergic antidepressants in treating panic disorder.

scholarly journals Panic disorder and hyperventilation

1999 ◽  
Vol 57 (4) ◽  
pp. 932-936 ◽  
Author(s):  
ANTONIO EGIDIO NARD ◽  
ALEXANDRE M. VALENÇA ◽  
ISABELLA NASCIMENTO ◽  
MARCO A. MEZZASALMA ◽  
WALTER ZIN
Keyword(s):  
Panic Disorder ◽  
Respiratory Physiology ◽  
Panic Attacks ◽  
Shortness Of Breath ◽  
Test Results ◽  
Simple Test ◽  
Normal Volunteers ◽  
Before And After ◽  
Dsm Iv ◽  
Drug Free

Respiratory abnormalities are associated with anxiety, particularly with panic attacks. Symptoms such as shortness of breath, "empty-head" feeling, dizziness, paresthesias and tachypnea have been described in the psychiatric and respiratory physiology related to panic disorder. Panic disorder patients exhibit both behaviorally and physiologically abnormal responses to respiratory challenges tests. Objective: We aim to observe the induction of panic attacks by hyperventilation in a group of panic disorder patients (DSM-IV). Method: 13 panic disorder patients and 11 normal volunteers were randomly selected. They were drug free for a week. They were induced to hyperventilate (30 breaths/min) for 3 minutes. Anxiety scales were taken before and after the test. Results: 9 (69.2%) panic disorder patients and one (9.1%) of control subjects had a panic attack after hyperventilating (p< 0.05). Conclusion: The panic disorder group was more sensitive to hyperventilation than normal volunteers. The induction of panic attacks by vonluntary hyperventilation may be a useful and simple test for validating the diagnosis in some specific panic disorder patients.

scholarly journals Effects of acute tryptophan depletion on mood and suicidal ideation in bipolar patients symptomatically stable on lithium

2000 ◽  
Vol 177 (5) ◽  
pp. 447-451 ◽  
Author(s):  
J. H. Hughes ◽  
F. Dunne ◽  
A. H. Young
Keyword(s):  
Suicidal Ideation ◽  
Random Order ◽  
Lithium Carbonate ◽  
Brain Serotonin ◽  
Acute Tryptophan Depletion ◽  
Tryptophan Depletion ◽  
Double Blind ◽  
Plasma Tryptophan ◽  
Patient Groups ◽  
Bipolar Patients

BackgroundPrevious studies suggest that brain serotonin neurotransmission may mediate the actions of lithium carbonate. Acute tryptophan depletion reduces brain serotonin and allows the study of this neurotransmitter in patient groups.AimsTo examine the effects of acute tryptophan depletion on mood and suicidal ideation in bipolar patients who were symptomatically stable on lithium.MethodNineteen subjects satisfying DSM–IV criteria for bipolar I disorder participated in a within-subject, double-blind, placebo-controlled random-order crossover study. Symptoms were evaluated following acute tryptophan depletion, which was induced by a 100 g amino acid drink following an overnight fast.ResultsPlasma tryptophan fell significantly after the depleting drink, but not after the control drink (P < 0.05, paired t-test, mean reduction 83%). No significant changes in mood or suicidality scores were recorded after acute tryptophan depletion.ConclusionsAcute tryptophan depletion does not reverse lithium's effects on mood and suicidality in bipolar disorder.

scholarly journals Oxytocinergic modulation of threat-specific amygdala sensitization in humans is critically mediated by serotonergic mechanisms

2020 ◽  
Author(s):  
Congcong Liu ◽  
Chunmei Lan ◽  
Keshuang Li ◽  
Feng Zhou ◽  
Shuxia Yao ◽  
...  
Keyword(s):  
Therapeutic Potential ◽  
Acute Tryptophan Depletion ◽  
Placebo Control ◽  
Tryptophan Depletion ◽  
Social Emotional ◽  
Double Blind ◽  
Link Type ◽  
Parallel Group ◽  
Emotional Effects

AbstractBackgroundOverarching conceptualizations propose that the complex social-emotional effects of oxytocin (OXT) in humans are partly mediated by interactions with other neurotransmitter systems. Recent animal models suggest that the anxiolytic effects of OXT are critically mediated by the serotonin (5-HT) system, yet direct evidence in humans is lacking.MethodsTo determine the role of 5-HT in OXT-induced attenuation of amygdala threat reactivity and sensitization/ desensitization, we conducted a parallel-group randomized placebo-controlled double-blind experiment during which n = 121 healthy subjects underwent a transient decrease in 5-HT signaling via acute tryptophan depletion (ATD, TRYP-) or the corresponding placebo-control protocols before the administration of intranasal OXT or placebo intranasal spray, respectively. Mean and repetition-dependent changes in threat-specific amygdala reactivity towards threatening stimuli (angry faces) as assessed by fMRI served as the primary outcome.ResultsNo treatment main or interaction effects on amygdala threat reactivity were observed, yet OXT switched bilateral amygdala threat sensitization to desensitization and this effect was significantly attenuated during decreased central 5-HT signaling via pretreatment with TRYP-.ConclusionsThe present findings provide the first evidence for a role of OXT in threat-specific amygdala desensitization in humans and suggest that these effects are critically mediated by the 5-HT system. OXT may have a therapeutic potential to facilitate amygdala desensitization and adjunct up-regulation of 5-HT neurotransmission may facilitate OXT’s anxiolytic potential.The trial was preregistered on clinicaltrials.gov (https://clinicaltrials.gov/ct2/show/NCT03426176, ID NCT03426176)

scholarly journals Evaluating the role of serotonin in hot flashes after breast cancer using acute tryptophan depletion

2009 ◽  
Vol 16 (4) ◽  
pp. 644-652 ◽  
Author(s):  
Janet S. Carpenter ◽  
Menggang Yu ◽  
Jingwei Wu ◽  
Diane Von Ah ◽  
Jennifer Milata ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Hot Flashes ◽  
Acute Tryptophan Depletion ◽  
Tryptophan Depletion

scholarly journals Double-blind clonazepam vs placebo in panic disorder treatment

2000 ◽  
Vol 58 (4) ◽  
pp. 1025-1029 ◽  
Author(s):  
ALEXANDRE MARTINS VALENÇA ◽  
ANTONIO EGIDIO NARDI ◽  
ISABELLA NASCIMENTO ◽  
MARCO A. MEZZASALMA ◽  
FABIANA L. LOPES ◽  
...  
Keyword(s):  
Panic Disorder ◽  
Rating Scale ◽  
Panic Attacks ◽  
Fixed Dose ◽  
Fisher Exact Test ◽  
Double Blind ◽  
Exact Test ◽  
Dsm Iv ◽  
Disorder Treatment ◽  
Hamilton Rating Scale

OBJECTIVE: To assess the effectiveness of clonazepam, in a fixed dose (2 mg/day), compared with placebo in the treatment of panic disorder patients. METHOD: 24 panic disorder patients with agoraphobia were randomly selected. The diagnosis was obtained using the structured clinical interview for DSM-IV . All twenty-four subjects were randomly assigned to either treatment with clonazepam (2 mg/day) or placebo, during 6 weeks. Efficacy assessments included: change from baseline in the number of panic attacks; CGI scores for panic disorder; Hamilton rating scale for anxiety; and panic associated symptoms scale. RESULTS: At the therapeutic endpoint, only one of 9 placebo patients (11.1%) were free of panic attacks, compared with 8 of 13 (61.5%) clonazepam patients (Fisher exact test; p=0,031). CONCLUSION: the results provide evidence for the efficacy of clonazepam in panic disorder patients.

scholarly journals Effects of a novel method of acute tryptophan depletion on plasma tryptophan and cognitive performance in healthy volunteers

2004 ◽  
Vol 178 (1) ◽  
pp. 92-99 ◽  
Author(s):  
E. A. T. Evers ◽  
D. E. Tillie ◽  
F. M. van der Veen ◽  
C. K. Lieben ◽  
J. Jolles ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Cognitive Performance ◽  
Acute Tryptophan Depletion ◽  
Tryptophan Depletion ◽  
Plasma Tryptophan ◽  
Novel Method

Paroxetine in the Treatment of Panic Disorder a Randomised, Double-Blind, Placebo-Controlled Study

1995 ◽  
Vol 167 (3) ◽  
pp. 374-379 ◽  
Author(s):  
S. Oehrberg ◽  
P. E. Christiansen ◽  
K. Behnke ◽  
A. L. Borup ◽  
B. Severin ◽  
...  
Keyword(s):  
Panic Disorder ◽  
Cognitive Therapy ◽  
Panic Attacks ◽  
Controlled Study ◽  
Positive Trend ◽  
Double Blind ◽  
Treatment Groups ◽  
Efficacy Measures ◽  
The Mean ◽  
Primary Measure

BackgroundThis study compared the efficacy and tolerability of paroxetine with placebo in the treatment of panic disorder.MethodAfter three weeks of placebo, patients received 12 weeks of treatment with paroxetine (20, 40, or 60 mg) or placebo, and finally two weeks of placebo. Dosages were adjusted according to efficacy and tolerability. Standardised cognitive therapy was given to all patients. The primary measure of outcome was reduction in the number of panic attacks.ResultsAnalysis of the results showed statistically significant differences in favour of paroxetine between the two treatment groups in two out of the three primary measures of outcome, i.e. 50% reduction in total number of panic attacks and number of panic attacks reduced to one or zero over the study period. For the third measure of outcome, the mean change in the total number of attacks from baseline, there was a positive trend in favour of paroxetine. The results of the primary measures of outcome were strongly supported by the results of the secondary efficacy measures of outcome. In addition, paroxetine, at all doses, was very well tolerated.ConclusionParoxetine plus cognitive therapy was significantly more effective than placebo plus cognitive therapy in the treatment of panic disorder.

Sertraline in the treatment of panic disorder

1998 ◽  
Vol 173 (1) ◽  
pp. 54-60 ◽  
Author(s):  
Peter D. Londborg ◽  
Robert Wolkow ◽  
Ward T. Smith ◽  
Eugene Duboff ◽  
Donald England ◽  
...  
Keyword(s):  
Panic Disorder ◽  
Adverse Events ◽  
Drop Out ◽  
Panic Attacks ◽  
Efficacy And Safety ◽  
Serious Adverse Events ◽  
Double Blind ◽  
Hamilton Anxiety Scale ◽  
Higher Doses ◽  
Clinical Global Impression Improvement

BackgroundThis study compared the efficacy and safety of sertraline to placebo in treating panic disorder.Method178 out-patients with panic disorder who exhibited at least four panic attacks during the four weeks prior to screening and three during the two weeks of lead-in were randomly assigned to 12 weeks of double-blind treatment with sertraline (50, 100 or 200 mg) or placebo.ResultsSertraline was superior to placebo in reducing the number of panic attacks, situational attacks, unexpected attacks, limited symptom attacks, and time spent worrying (all P < 0.01) and the Hamilton Anxiety Scale (P < 0.05), although Clinical Global Impression (Improvement) did not significantly differentiate groups at 12 weeks and at end-point. No serious adverse events were associated with sertraline. No dose relationship was found for adverse events; overall drop-out rates were not different for sertraline or placebo, although more sertraline-treated subjects discontinued for adverse events, typically early in the study. Only dry mouth and ejaculation failure (primarily ejaculation delay) were associated significantly with sertraline. Conclusions Sertraline was effective and safe in reducing panic attacks. Higher doses were no more effective than the 50 mg dose.

Platelet serotonin binding and plasma cortisol in panic disorder before and after alprazolam plus behavioral guidance treatment

1991 ◽  
Vol 6 (1) ◽  
pp. 31-37
Author(s):  
A Tobeña ◽  
X Sanchez ◽  
J Masana ◽  
MJ Martinez de Osaba
Keyword(s):  
Panic Disorder ◽  
Treatment Period ◽  
Plasma Cortisol ◽  
Panic Attacks ◽  
Platelet Serotonin ◽  
Before And After ◽  
Anxious State ◽  
Cortisol Levels ◽  
Normal Controls

SummaryIn 32 patients with panic disorder with or without agoraphobia, Bmax measures of 5-HT binding in platelets did not differ from normal controls at baseline. Plasmatic cortisol levels were significantly higher than controls in the morning and in the evening measures as well as in post-dexamethasone assays. Following an 8-week treatment period with alprazolam plus behavioral guidance encouraging exposure, Bmax values did not alter but cortisol measures diminished significantly. Measures of phobic avoidance were negatively correlated with 5-HT Bmax values. Plasmatic cortisol correlated positively with the number of situational panic attacks in the month before treatment. There were no correlations between cortisol and 5-HT Bmax measures. A possible link between serotonin function and phobic avoidance is discussed. Cortisol changes were interpreted as being related to the global severity of the anxious state.

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