Biomedical subjects
R B Lydiard
Publications and source records attributed to R B Lydiard.
Phenelzine treatment of panic disorder: lack of effect on pyridoxal phosphate levels.
Earlier reports indicated that phenelzine treatment may result in clinically significant reductions of vitamin B6 in some individuals. Sixteen subjects, ages 21-59 years (seven men, nine women) with panic disorder with or without agoraphobia were treated with an average of phenelzine 53.5 mg/day for an average of 10 weeks in an open treatment study. No significant effects on plasma levels of pyridoxal phosphate, the active form of vitamin B6, were discernible in this group, nor was there any clear relationship between pyridoxal phosphate levels and symptoms in the subgroup of five patients who did develop deficiency-type symptoms. Pyridoxine replacement had unclear effects in symptomatic patients.
Secondary depression in panic disorder and agoraphobia. I. Frequency, severity, and response to treatment.
Depressive symptomatology in 481 subjects with panic disorder and phobic avoidance was studied as part of an investigation of the efficacy of alprazolam in panic disorder. Subjects who had a major depressive episode (MDE) before the onset of their panic disorder were not included in the trial. With this exclusion criterion, 31% of subjects had a secondary MDE occurring after the onset of the panic disorder. The occurrence of secondary MDE was related to the length of time subjects were ill with panic disorder. Compared with the subjects without depression, those subjects with current MDE had higher scores on measures of anxiety and depression but not on the number of panic attacks per week. The presence of depression and the degree of phobic avoidance contributed independently to measures of the severity of the panic illness. Alprazolam was effective in reducing panic and depressive symptomatology in both depressed and nondepressed subjects with panic disorder. The presence of an MDE was not predictive of the outcome of treatment for the panic and phobic symptoms. Subjects with or without depression responded similarly to alprazolam.
Precursor amino acid concentrations in normal weight bulimics and normal controls.
1. CNS serotonergic neurotransmission has been implicated in the control of appetitive behavior. The ratio of plasma tryptophan (TRP) to other large neutral amino acids (LNAA) is believed to regulate CNS serotonin (5-HT) synthesis. 2. After an overnight fast, plasma TRP ratios were determined in 23 normal weight bulimics and 7 normal controls. 3. All subjects were assessed for mood disorder using a SADS interview and Beck Depression ratings. 4. There was no significant difference in TRP ratios between bulimics and normal controls. TRP ratios in depressed bulimics were not significantly different from those of nondepressed bulimics. 5. Potential abnormalities in CNS serotonergic function in bulimics are not reflected in decreased baseline TRP ratios. Further investigation of the dynamic serotonergic system may prove fruitful. 6. Reduced availability of tryptophan for conversion to serotonin is not likely to be the postulated biological abnormality common to both depression and bulimia.
Possible relationship of bowel obsessions to panic disorder with agoraphobia.
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Recent advances in the psychopharmacological treatment of anxiety disorders.
The authors review recent progress in the pharmacological treatment of anxiety disorders. Most research within the last five years has focused on panic disorder; the findings include support for the usefulness of imipramine and clomipramine and probably other agents; evidence that the benzodiazepines alprazolam, diazepam, lorazepam, and clonazepam are approximately equally effective as antipanic agents; and high variability in relapse rates after discontinuation of drug treatment. Further work is required to determine whether buspirone and other forthcoming serotonin agonist drugs have a role in treating panic disorder and other anxiety disorders. For generalized anxiety disorder, scientific studies do not support the effectiveness of beta blocker; tricyclics may be potentially useful. Psychopharmacological treatments for social phobia, obsessive-compulsive disorder, and posttraumatic stress disorder are also reviewed.
Prediction of response to antipsychotics.
This review surveys the literature in the area of predictors of response to antipsychotic drugs. Four general categories are presented and discussed: diagnosis as a predictor, clinical predictors, biological predictors, and pharmacological predictors. No single consistent predictor of response could be discerned; it appears that a variety of factors affect outcome and that several variables must be considered simultaneously. Based on the findings of this review, suggestions for improvements in clinical research design are made.
Alprazolam in the treatment of social phobia.
Pharmacological treatment of social phobia has not been extensively studied. Recent reports suggest that social phobia may be treated with monoamine oxidase inhibitors, tricyclic antidepressants, beta-blockers, or clonidine. The authors describe four patients with social phobia who responded moderately to markedly well when treated with the triazolobenzodiazepine alprazolam. Patients with social phobia and patients with agoraphobia with panic attacks differ in the focus of anxiety, sensitivity to lactate infusion, and the pattern of symptoms during anxiety episodes. However, there is significant overlap in the clinical features of these two patient groups. The preliminary finding that several types of pharmacological agents that are effective in treating agoraphobia with panic attacks may also be effective in treating social phobia suggests that the two disorders may share some common pathophysiology.
Lack of pharmacokinetic interaction between tranylcypromine and carbamazepine.
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Sexual side effects of alprazolam.
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Emergence of depressive symptoms in patients receiving alprazolam for panic disorder.
The authors relate their clinical experience with 46 panic disorder patients who were receiving 3-10 mg/day of alprazolam. Fifteen (33%) developed symptoms consistent with DSM-III criteria for major depression despite remission of their panic symptoms. Clinicians should be alert to this potentially reversible complication.
Successful utilization of maprotiline in a panic disorder patient intolerant of tricyclics.
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Preliminary results of an open, fixed-dose study of desipramine in panic disorder.
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Desipramine in agoraphobia with panic attacks: an open, fixed-dose study.
Fourteen patients who met DSM-III criteria for agoraphobia with panic attacks received 200 mg desipramine (DMI) per day for 12 to 16 weeks on an open basis. Seven of eight patients who responded had steady state plasma DMI levels greater than 125 ng/ml, while five of six nonresponders had DMI levels less than 125 ng/ml. Following increases in dosage sufficient to raise DMI levels to greater than 150 ng/ml, four nonresponders improved dramatically. Implications of these findings are discussed briefly.
Past and current thyroid function in subjects with panic disorder.
Disturbances in thyroid function can result in symptoms similar to those occurring in patients with anxiety disorders, especially panic disorder. An association between thyroid illness and panic and phobic disorders has been suggested, but few studies have directly investigated this issue. To assess this possible relationship, the authors measured indices of thyroid function in 165 subjects who had a current DSM-III diagnosis of panic disorder, either with or without phobic avoidance. These subjects reported a higher prevalence of thyroid illness by history compared with the prevalence of thyroid illness in the general population; however, less than 1% of all subjects had current thyroid dysfunction. The presence of a major depressive episode (MDE) was unrelated to current thyroid function, although subjects with MDE reported a higher prevalence of thyroid disease by history. Indices of thyroid function were not correlated with the severity of panic attacks or phobias.
Obsessive-compulsive disorder successfully treated with trazodone.
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Lithium therapy revisited.
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