Biomedical subjects

R J Maddock

Publications and source records attributed to R J Maddock.

50 records · Page 3Linked to original sources

PubMed1992

Chest pain in generalized anxiety disorder.

OBJECTIVES: The objectives of the current study were to evaluate the prevalence of chest pain and related medical utilization in patients with generalized anxiety disorder and to investigate the possible relationship between the occurrence of chest pain in these patients and the episodes of excessive worry which characterize this disorder. METHOD: The presence of a history of chest pain in patients with generalized anxiety disorder was investigated in an outpatient psychiatric sample using a structured interview which also assessed related medical utilization and the relationship of chest pain to panic attacks and episodes of excessive worry. RESULTS: Of fifty sequentially evaluated patients meeting DSM-III R criteria for G.A.D., twenty-four (48%) reported a history of chest pain. Seven of these patients also had a history of panic attacks, however, four of the seven reported that their pain occurred independently of their panic attacks. Sixteen patients with G.A.D. reported that their chest pain episodes were associated with episodes of excess worry. Eleven had sought medical evaluation for their pain. Patients with chest pain and normal coronary arteries are frequently found to have panic disorder. The pattern of utilization of medical care was comparable in this sample of patients with G.A.D. and a group of patients with panic disorder recruited in a similar manner. CONCLUSIONS: These results suggest that in addition to panic disorder, G.A.D. may also be a common diagnosis in chest pain patients with no demonstrable coronary disease. Future studies of coronary artery disease negative patients with chest pain should include assessments for the presence of G.A.D. Our results also suggest that chest pain may be a common symptom in G.A.D. The possibility that chest pain should be included in the diagnostic criteria for this disorder should be the subject of further investigation.

Adult↗

PubMed1991

Hyperventilation-induced panic attacks in panic disorder with agoraphobia.

Eight minutes of hyperventilation to an end-tidal PCO2 of less than 20 mmHg led to a panic attack in 7 of 12 patients with panic disorder with agoraphobia and only 1 of 12 normal controls. Patients experienced greater increases in panic symptoms than controls during hyperventilation. Patients who reported more distress from somatic symptoms of hyperventilation during the preceding week were more likely to panic during hyperventilation. Patients who panicked during hyperventilation exhibited a delayed recovery of normocapnia following hyperventilation. Hyperventilation by this protocol is an effective means of inducing panic attacks in the laboratory. A hyperventilation challenge may identify a subgroup of patients for whom hyperventilation symptoms are frequently associated with panic.

Adult↗

PubMed1991

Elevated serum lactate associated with panic attacks induced by hyperventilation.

Several lines of evidence suggest that lactate metabolism may be altered in panic disorder. We recently reported exaggerated increases in serum lactate in panic patients following hyperventilation during glucose infusion. In the current study, lactate metabolism was stimulated by hyperventilation following glucose ingestion in 12 panic patients and 12 controls. The seven patients who panicked during hyperventilation exhibited larger increases in serum lactate levels than nonpanicking patients or controls. The lactate response was significantly correlated with peak ratings of anxiety and panic symptoms, but not correlated with insulin or cortisol levels, heart rate, pCO2, adiposity, exercise habits, or diet. Hyperventilation-induced panic appears to be associated with metabolic changes leading to elevated serum lactate.

Adult↗

PubMed1991

Beta receptor density in human lymphocyte membranes: changing with aging?

The number of beta adrenergic binding sites (Bmax) in human lymphocyte membranes has been reported to decrease, remain the same, or increase with age. In order to address this issue, we used two highly specific beta receptor ligands with lymphocytes from healthy aged (range: 51-90 years) and young (19-39 years) subjects in two separate studies. Because depression can reduce Bmax, potential aged subjects were excluded if they had high scores on tests for depression. Bmax was higher in the aged group of each study (33% higher in the first, p less than .01, and 72.5% in the second, p less than .02); the results were similar in both studies. Antagonist affinity did not differ between young and aged groups in either study. We suggest that some of the discrepancies in the literature could be due to differences in age ranges used or to inclusion of depressed subjects in prior studies.

Adrenergic beta-Antagonists↗

PubMed1991

Response to treatment in panic disorder with associated depression.

Thirty outpatients with panic disorder (PD) were treated at an anxiety clinic using a symptom-focused approach. Thirteen (43%) had no history of major depressive disorder (MDD), 12 (40%) had a history of secondary MDD, and 5 (17%) had history of primary MDD. The outcome was equally good in patients with no history of MDD (77% had good or excellent outcomes) and patients with a history of secondary MDD (83% had good or excellent outcomes). Patients with a history of primary MDD had the worst outcomes. These findings agree with earlier studies showing that secondary MDD does not adversely affect prognosis of patients presenting for treatment of PD.

Adult↗

PubMed1990

Elevated serum lactate following hyperventilation during glucose infusion in panic disorder.

Early investigators reported that patients with anxiety syndromes associated with panic attacks produced more lactate during exercise than control subjects. These studies suggested a metabolic difference between patients and controls. However, the possibility that patients were simply less fit than controls could not be excluded. In this study, serum lactate was measured in panic disorder patients in response to a metabolic challenge not involving exercise. Voluntary hyperventilation during iatrogenic hyperglycemia led to an increase in serum lactate. The increase in serum lactate was significantly greater in panic disorder patients than in controls. Hyperventilation provoked panic attacks in 4 of 8 patients and none in 6 controls. There was no evidence of a relationship between the increase in lactate or the associated decrease in phosphate and the level of anxiety produced by this procedure.

Adult↗

PubMed1989

Lymphocyte beta-adrenoreceptor density in patients with unipolar depression and normal controls.

Values of binding maximum (Bmax) and dissociation constant (Kd) of (-)3-[125I]iodocyanopindolol (ICYP) were determined in beta-adrenergic receptors of membranes of peripheral lymphocytes in 32 patients with unipolar depression (DSM-III-R) and 31 normal controls. Results were analyzed by a two-way Analysis of Covariance method. A significant difference was noted for group assignment (patient versus control, p less than 0.05). Mean Bmax (fmol ICYP bound/mg lymphocyte membrane fraction total protein) of patients was 31.9 +/- 3.84 (SE) and controls 46.3 +/- 3.92 (SE). A significant interaction was found between group membership and gender (p less than 0.05). In the female patient group (n = 14), mean Bmax was 30.5 +/- 5.79 (SE); in female controls, mean Bmax was 56.0 +/- 5.15 (SE). Differences between male patients and male controls were not significant. Mean values of Kd (pmol/liter) showed a trend for patient values to be lower than control values [69.0 +/- 13.66 (SE) versus 108.5 +/- 14.42 (SE), respectively]. A significant inverse relationship was noted between lymphocyte beta-receptor Bmax and frequency of panic attacks during the depressive episode in 18 patients (p = 0.05). No relationship was found between values of Kd and frequency of panic attacks in these patients. Thus, preliminary evidence is provided for relationships among altered beta-adrenergic receptor binding, gender, and indices of panic-anxiety in unipolar depressed patients.

Adult↗

PubMed1987

Serum phosphate and anxiety in major depression.

Serum inorganic phosphate was measured in 33 hospitalized patients with unipolar depression. As predicted, serum phosphate showed significant negative correlations with Minnesota Multiphasic Personality Inventory scales sensitive to anxiety (Psychasthenia: -0.33) and somatic concern (Hypochondriasis: -0.51). This is consistent with previous observations of relative hypophosphatemia in patients with panic disorder. Clinical consequences of relative hypophosphatemia and the possible roles of hyperventilation or elevated peripheral catecholamines as mediators of this effect are discussed.

Adult↗

PubMed1986

Lactate infusions and panic attacks: do patients and controls respond differently?

Ten patients with panic disorder or agoraphobia with panic attacks and 10 normal controls received infusions of normal saline (placebo) and sodium lactate in a single-blind design. The time course of changes in the dependent variables was closely monitored, and expectancy biases and demand characteristics were minimized. Lactate increased self-reported anxiety and heart rate equally in patients and controls. The only variables showing statistically different responses between the groups were systolic and diastolic blood pressure. Overall, in both groups, the effects of lactate were quite similar to states of natural panic or anxiety for both self-report measures and heart rate. Patients had a tendency to endorse somatic symptoms indiscriminately. Our data do not support response to lactate as a biological marker of proneness to panic attacks.

Adult↗

PubMed1986

Ambulatory heart rate changes in patients with panic attacks.

Of 33 "panic" attacks reported by patients wearing an ambulatory solid-state heart rate/activity monitor for 6 days, 19 (58%) occurred at heart rates disproportionate to activity levels and different enough from surrounding heart rates to indicate a distinct physiologic state. Intense panic attacks with three or more symptoms were the most readily identified. ECG monitoring found the elevated heart rates to be sinus tachycardias. Heart rate elevation did not occur during anticipatory anxiety episodes. Ambulatory heart rate recordings confirm the presence of major physiologic changes during self-reported panic attacks.

Adolescent↗

PubMed1981

Accommodation responses and refractive error.

Previous investigations have reported considerable individual differences in the resting point of accommodation. Recent independent studies in Davis, Calif., and Cardiff, Wales, indicate that part of these variations are related to refractive errors. The average dioptric value of the resting point of accommodation is lowest for corrected myopes, highest for corrected hyperopes, and intermediate for emmetropes. Another part of the variation in resting point is related to individual differences in the far point accommodation. There appears to be no significant relationship between the resting point and near point of accommodation.

Accommodation, Ocular↗

PubMedDate not supplied

Generalized anxiety disorder patients seek evaluation for cardiological symptoms at the same frequency as patients with panic disorder.

Although panic disorder (PD) and generalized anxiety disorder (GAD) have similar somatic symptoms, panic attacks with chest pain and/or palpitations may seem more likely to be mistaken for heart attacks because of their acute onset. One would therefore expect that PD patients are more likely than GAD patients to seek cardiological consultations. In a survey of 146 PD and 154 GAD patients entering a multi-site drug trial, we found virtually identical rates of such consults. Approximately 50% of each patient group sought medical evaluation for cardiac symptoms. Furthermore, 40% of each group had standard treadmill evaluations and 33% reported having an echocardiogram. This study suggests that future epidemiological studies in cardiology populations should include probes for generalized anxiety disorder.

Anxiety Disorders↗

PubMedDate not supplied

Hypocapnia associated with cardiac stress scintigraphy in chest pain patients with panic disorder.

OBJECTIVE: Patients with recurrent chest pain but no evidence of coronary artery disease often meet diagnostic criteria for panic disorder (PD). However, it can be argued that the phenomenological diagnosis of PD may not be valid in these normal coronary chest pain (NCCP) patients. The purpose of this study is to additionally validate the diagnosis of PD in chest pain patients by comparing PCO2 levels before and during myocardial stress scintigraphy in those with and without PD. METHOD: End-tidal PCO2 was measured before and during myocardial stress scintigraphy in 22 patients being evaluated for chest pain. Psychiatric diagnoses were assessed by structured interview. RESULTS: Eleven of the 19 patients (58%) with negative scintigrams met DSM-III-R diagnostic criteria for current panic disorder. Prestress PCO2 levels were significantly lower in these patients. Eight of the nine NCCP patients with prestress PCO2 < 34 mm Hg had PD. CONCLUSIONS: The finding of stress-related hypocapnia associated with PD in NCCP patients provides additional support for the validity of the diagnosis of PD in this population. The potential value of PCO2 measurements in screening for PD in patients with chest pain merits additional study.

Aged↗

PubMedDate not supplied

The effect of alcohol on the vestibulo-ocular reflex and apparent concomitant motion.

Measures of the vestibulo-ocular reflex (VOR) and apparent concomitant motion (ACM), the apparent motion of stationary visual stimuli during head motion, were obtained during sessions in which subjects consumed either alcoholic or placebo beverages. Both VOR and ACM remained constant throughout the placebo sessions. During sessions in which alcohol was consumed, the gain of the VOR was reduced and there was an increased tendency to see ACM in the direction opposite head motion. The effects of alcohol on ACM were greatest 50 min following cessation of drinking, near the maximum of the blood alcohol concentration (BAC). ACM measures then returned towards baseline, whereas the BAC measures remained elevated. VOR gain alterations paralleled the BAC measures. Therefore, reduction of VOR gain with alcohol produces an increase of ACM, but the ACM changes are relatively transient when compared with the altered VOR gain.

Adult↗