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Biomedical subjects

R B Lydiard

Publications and source records attributed to R B Lydiard.

At least 91 records · Page 5Linked to original sources

Evaluation of the ratings comprising the associated symptom criterion of DSM-III-R generalized anxiety disorder.

In light of ongoing considerations for DSM-IV, the 18 ratings comprising the associated symptom criterion of DSM-III-R generalized anxiety disorder were evaluated. The interrater reliability and endorsement rates of each symptom were calculated from interview-based ratings of generalized anxiety disorder patients at four sites (total N = 204). Interrater reliability analyses indicated high agreement for the majority of the 18 symptoms. Regarding the frequency of symptom endorsement, significant Spearman correlations (range = .69 to .94) revealed marked consistency in the rates of symptom endorsement across the four sites. A list of "satisfactory" symptoms was generated from those meeting certain reliability and endorsement criteria. Seven symptoms were identified: irritability, restlessness, muscle tension, difficulty concentrating, sleep difficulties, feeling keyed up, and easy fatigability. Interestingly, all of the above belong to either the motor tension or vigilance and scanning clusters of the DSM-III-R associated symptom ratings. In contrast, symptoms belonging to the autonomic hyperactivity cluster were endorsed infrequently at all sites. Although additional research is needed (e.g., examination of the symptoms' discriminant validity), these findings essentially support revising the associated symptom criterion of generalized anxiety disorder in accord with option E3 in the DSM-IV Options Book.

Adult↗

CSF cholecystokinin octapeptide in patients with bulimia nervosa and in normal comparison subjects.

Cholecystokinin octapeptide (CCK-8) appears to modulate appetitive behavior, and in rodents, anxiety-related behavior. The authors studied CCK-8 in patients with bulimia nervosa. CSF concentrations of CCK-8 were measured in 11 drug-free female patients with DSM-III-R-defined bulimia nervosa and in 16 normal subjects. The bulimic patients had significantly lower levels of CCK-8 than the comparison subjects. CCK-8 concentrations were inversely correlated with scores on the anger-hostility, anxiety, and interpersonal sensitivity subscales of the SCL-90-R. They were not significantly correlated with age, percentage of standardized average body weight, or mean weekly frequency of binge eating or vomiting. The results indicate that central CCK-8 abnormalities may play a role in the pathophysiology of bulimia nervosa.

Adult↗

Psychiatric comorbidity in patients with generalized anxiety disorder.

OBJECTIVE: The goal of this study was to test the validity of generalized anxiety disorder as an independent diagnostic entity and to evaluate the prevalence and type of other psychiatric disorders coexisting with generalized anxiety disorder. Although a few published studies have addressed the subject, this study presents data from a larger group of subjects and excludes concurrent major depression as a potential confound. METHOD: The authors studied patients with a primary diagnosis of generalized anxiety disorder assigned after evaluation with the Structured Clinical Interview for DSM-III-R. Patients with a concurrent major depressive episode were excluded. All diagnoses for which the patient met criteria were determined, including lifetime occurrence of major depressive episode and substance use. RESULTS: One hundred nine patients with generalized anxiety disorder were included in the analysis. Twenty-eight (26%) of these patients were not given any other lifetime psychiatric diagnosis. The most prevalent comorbid diagnoses were social phobia (25 [23%] of the patients) and simple phobia (23 [21%] of the patients). Forty-six (42%) of the patients with generalized anxiety disorder had experienced at least one major depressive episode during their lifetime. CONCLUSIONS: These results support previous findings of high rates of psychiatric comorbidity in generalized anxiety disorder and validate the usefulness of generalized anxiety disorder as a separate diagnostic entity.

Adult↗

Cerebrospinal fluid thyrotropin-releasing hormone concentrations in patients with anxiety disorders.

In a study of 45 patients with anxiety disorders and 11 control subjects, mean cerebrospinal fluid (CSF) concentrations of thyrotropin-releasing hormone (TRH) were not significantly different between nonpsychiatric control subjects and those with panic disorder, generalized anxiety disorder, or obsessive-compulsive disorder. Male subjects, regardless of diagnosis, had significantly higher mean CSF concentrations of TRH than females.

Adult↗

Lithium side effects in the medically ill.

OBJECTIVE: This review will include the general pharmacology of lithium and discuss its effects on various organ systems, with emphasis on the medically ill patient as well as the geriatric patient with multiple medical problems. METHODS: A full literature review on the side effects of lithium was performed. Attention is focused on the medically ill and possible drug interactions. RESULTS: This review points to the numerous problems which can result in toxicity in the medically ill or the geriatric patient. CONCLUSION: Serious side effects can be avoided with proper drug monitoring and knowledge of potential drug interactions.

Bipolar Disorder↗

Preliminary report: placebo-controlled, double-blind study of the clinical and metabolic effects of desipramine in panic disorder.

Fifty-six males and females with panic disorder with or without agoraphobia participated in a 12-week, placebo-controlled treatment study of the efficacy of desipramine (DMI). Twenty-six of 28 patients receiving DMI completed the study; 17 of 28 placebo (PBO) recipients completed 12 weeks. Patients receiving DMI responded significantly better than did PBO recipients as measured by Hamilton Anxiety Scale (HAM-A) and global phobia ratings, with a trend toward greater global improvement, but no between-group differences on panic attack frequency were discerned. By Week 12, 22 of 26 (85%) DMI patients were panic-free; 13 of 17 (76%) PBO patients were panic-free. Resting metabolic rate (RMR) was tested on a subset of the patients. Patients receiving DMI showed no effects on RMR or thyroid indices but lost a significant amount of weight; the PBO recipients exhibited no weight loss or RMR effects. In this study, the high PBO response rate obscured treatment group differences on some measures. This study underscores the need for placebo comparisons in treatment studies. In summary, DMI appears to be an effective treatment for panic disorder. DMI appears to have little effect on RMR; a slight but significant weight loss was observed in the DMI but not PBO group.

Adolescent↗

Cardiovascular effects of imipramine, fluvoxamine, and placebo in depressed outpatients.

BACKGROUND: The data presented represent cardiovascular parameters collected from one site of a larger, multicenter, double-blind, placebo-controlled, 6-week outpatient efficacy study of the serotonin uptake inhibitor fluvoxamine in depressed outpatients. METHOD: In this smaller study, we compared fluvoxamine (N = 17) to the prototypic antidepressant, imipramine (N = 14), and to placebo (N = 15). Specific parameters investigated were drug effects on postural pulse and blood pressure changes and ECG parameters including PR, QRS, and QTc intervals and ventricular heart rate. RESULTS: Fluvoxamine had few effects on measured parameters. Imipramine produced statistically significant changes on all measures; placebo had no effects on cardiac measures. CONCLUSION: Our data support that fluvoxamine, in a sample of healthy depressed outpatients, has little effect on cardiovascular function. Further study and clinical experience with this drug will be necessary before the full extent of its cardiac profile is known.

Adult↗

CSF diazepam-binding inhibitor concentrations in panic disorder.

Diazepam-binding inhibitor (DBI) is a neuropeptide that has been detected in the brain and cerebrospinal fluid (CSF). Previous studies have suggested the possible role of DBI as a potential endogenous anxiogenic ligand modulating GABAergic transmission at the benzodiazepine-GABA receptor complex. The measurement of DBI immunoreactivity (DBI-IR) in CSF of panic-disorder patients and normal controls was undertaken to assess whether there were differences in the CSF concentration of this peptide to assess possible relationships with other monoamines and peptides. Lumbar CSF was obtained from 18 panic patients (4 men, 14 women) and 9 controls (5 men, 4 women). As a group, no significant differences were found between panic patients' CSF concentration of DBI-IR (1.12 +/- 0.27 pmol/mL) and normal volunteers (1.23 +/- 0.27 pmol/mL). No gender differences were demonstrated. However, we did find a positive correlation between CSF levels of DBI and CSF corticotropin releasing hormone (CRH) in our panic patients.

Adult↗

Cardiovascular status of panic disorder patients with and without prominent cardiac symptoms.

The extent of the cardiovascular evaluation of panic disorder patients with cardiac symptoms remains a dilemma for the clinician. The authors conducted a pilot study to assess the cardiac status of 20 panic disorder patients, 10 of whom had prominent cardiac symptoms and 10 of whom did not. No differences in the cardiac abnormalities were found between the groups. These findings suggest that panic disorder patients with cardiac symptoms are not more likely to have cardiac disease than those without prominent cardiac symptoms. The practical implications of these findings are discussed.

Adult↗

Bipolar affective disorder and substance abuse.

Epidemiologic data as well as data from treatment-seeking populations indicate that substance abuse disorders and other psychiatric disorders co-occur more commonly than would be expected by chance. In particular, substance abuse, especially cocaine abuse or dependence and alcoholism, is a far more common phenomenon in the population of patients with bipolar affective disorder than in the general population. National Institute of Mental Health Epidemiologic Catchment Area data indicate that bipolar affective disorder is the axis I disorder most likely to be associated with some form of substance abuse or dependence. Evidence from patient samples seeking treatment for substance abuse disorders as well as for psychiatric disorders suggests that clinical samples reflect similar patterns. There is evidence that bipolar patients with substance abuse have a worse course of illness. Diagnosing bipolar affective disorder in the face of substance abuse is difficult because the effects of drugs of abuse, particularly with chronic use, can mimic nearly any psychiatric disorder. At present, the data concerning a genetic link between bipolar affective disorder and substance abuse disorders are inconclusive. There are very few controlled data addressing either clinical features of, or specific treatment efforts with, this population. There is some theoretic rationale for the use of anticonvulsant, antikindling agents in this population, but no controlled studies have as yet been reported. In particular, a comparison of a mood-stabilizing agent, such as lithium, with an antikindling agent, such as valproate or carbamazepine, would be of theoretic and practical interest.

Alcoholism↗

Alprazolam plasma concentrations and treatment response in panic disorder and agoraphobia.

OBJECTIVE: The authors' goal was to evaluate the relationship between plasma concentrations of alprazolam and both treatment response and side effects in patients with panic disorder and agoraphobia. METHOD: Ninety-six patients with panic disorder and agoraphobia were treated at three sites in a 6-week, fixed-dose, double-blind, placebo-controlled, dose-response study of 2 mg/day or 6 mg/day of alprazolam. Assessments were made of panic attacks, avoidance behavior, generalized anxiety, and global response. Blood samples were collected throughout the study and analyzed for alprazolam and other benzodiazepines. RESULTS: Patient compliance with the protocol was judged to be good on the basis of plasma concentrations. According to logistic regression analysis, the relationships between plasma alprazolam concentration and response, as reflected by number of panic attacks reported, phobia ratings, physicians' and patients' ratings of global improvement, and the emergence of side effects, were significant. However, there was no significant relationship between plasma alprazolam concentration and the degree of generalized anxiety symptoms. CONCLUSIONS: The authors conclude that plasma concentration of alprazolam is related to treatment response, particularly in panic attacks. The alprazolam concentration associated with treatment response or with emergence of a given side effect varied widely among individuals, highlighting the necessity for individualized dose adjustment to obtain optimal treatment response while minimizing side effects.

Adult↗

CSF cholecystokinin concentrations in patients with panic disorder and in normal comparison subjects.

Cholecystokinin concentrations in the CSF of 25 patients with panic disorder and 16 normal comparison subjects were ascertained by radioimmunoassay. The patients with panic disorder had significantly lower CSF concentrations of cholecystokinin, which may reflect increased CNS cholecystokinin receptor sensitivity, reduced numbers of receptors, or a compensatory reduction in cholecystokinin octapeptide secondary to theoretically increased central cholecystokinin tetrapeptide activity.

Adolescent↗

CSF beta-endorphin and dynorphin in bulimia nervosa.

OBJECTIVE: Preclinical and clinical evidence suggests that central opioid dysfunction may play a role in the pathophysiology of the eating disorders. In particular, endogenous opioids are known to regulate feeding behavior, mood, perception, and neuroendocrine function, all of which are disturbed in patients with eating disorders. Although low concentrations of CSF beta-endorphin have been reported in low-weight patients with anorexia nervosa, central opioid activity in normal-weight patients with bulimia nervosa has not been reported. The authors therefore measured CSF concentrations of beta-endorphin and dynorphin in drug-free female patients with DSM-III-R-defined bulimia nervosa and normal comparison subjects. METHOD: After 4 days of a low monoamine diet and overnight bed rest, CSF was obtained (12-26 cc) from 11 women with bulimia and 17 normal comparison subjects (eight women and nine men). RESULTS: The women with bulimia had significantly lower CSF concentrations of beta-endorphin than did the female comparison subjects. However, CSF concentrations of dynorphin were not significantly different in patients and female or male comparison subjects. beta-Endorphin concentrations were inversely correlated with Beck Depression Inventory scores and the depression subscale of the Eating Disorders Inventory. CONCLUSIONS: These data support a role for central opiates in the mediation of the pathophysiology of the signs and symptoms of bulimia nervosa, although it is impossible to rule out the effects of depression on the results.

Adult↗