High cholesterol levels in patients with panic disorder

OBJECTIVE

This study was undertaken to help clarify whether the higher cholesterol levels found in patients with panic disorder are a complication of panic disorder only or are associated with any psychiatric disorder.

METHOD

The subjects of the study were 30 patients with panic disorder and 30 patients with major depression, diagnosed according to the Structured Interview for DSM-III-R, and 30 normal control subjects. The three groups were matched for sex and age, and none of the subjects had alcohol/drug abuse, abnormal ECGs, or unstable medical conditions. Blood samples were drawn at random times, and serum cholesterol levels were determined.

RESULTS

The patients with panic disorder had significantly higher serum cholesterol levels than did the patients with major depression and the normal control subjects. Among the patients with major depression, histories (current or past) of anxiety disorders were associated with significant elevation of serum cholesterol levels. The presence of stable medical conditions was not associated with higher cholesterol levels in any of the three groups of subjects.

CONCLUSIONS

Higher cholesterol levels were particularly associated with panic disorder in comparison with major depression. Higher levels of cholesterol in panic disorder are hypothesized to be a result of increased noradrenergic activity, which may be the underlying biological/neurochemical mechanism for symptoms of panic disorder, including anticipatory anxiety.

Effect of acute and chronic benzodiazepines on plasma GABA in anxious patients and controls

The acute effects of diazepam on plasma GABA were determined in 18 patients with panic disorder, 13 patients with generalized anxiety disorder and 20 healthy controls. All subjects were benzodiazepine-naive. Four logarithmically increasing doses of diazepam/placebo were administered intravenously at 15-min intervals on 2 separate days. Plasma GABA was measured at baseline and 3 min after the highest dose of diazepam/placebo. There was an overall decrease in plasma GABA that was significantly greater following diazepam compared with placebo, but no group differences in response. In a separate group of 18 panic disorder patients receiving chronic benzodiazepine treatment with alprazolam, the same diazepam infusion procedure (no placebo day) produced decreases in plasma GABA similar to those seen in the untreated panic disorder patients. The clinical and physiologic implications of these findings are discussed.

Higher postdexamethasone serum cortisol levels in agoraphobic than in nonagoraphobic panic disorder patients

The dexamethasone suppression test (DST) was performed in panic disorder (PD) patients with (n = 32) or without (n = 31) agoraphobia and in normal controls (n = 49). Postdexamethasone serum cortisol levels were significantly higher in agoraphobic PD patients (105.3 +/- 19.3 nmol/L) both when compared to PD patients without agoraphobia (47.3 +/- 7.7 nmol/L; p less than 0.01) and when compared to healthy controls (51.7 +/- 8.3 nmol/L; p less than 0.01). The rate of nonsuppressors (i.e., subjects displaying postdexamethasone cortisol levels greater than 138 nmol/L) was 28% and 3% in agoraphobic and nonagoraphobic PD patients, respectively, and 12% in controls. In patients, the postdexamethasone cortisol levels did not correlate with the number of panic attacks per week, baseline anxiety as measured using the Hamilton Anxiety Scale, depressive symptoms as measured using the Montgomery-Asberg Depression scale, or duration of illness. Data from eight patients in whom a second DST was performed after treatment with imipramine or clomipramine for three months indicate that a marked reduction of the number of anxiety attacks is not necessarily accompanied by a normalization of a pathological DST. In conclusion, it is suggested that the elevated postdexamethasone cortisol levels sometimes observed in agoraphobic PD patients are more closely related to the agoraphobic behavior than to the panic attacks per se.

The changes of thyroid hormone during pharmacological treatment of panic disorder patients

1. Because imipramine has lowered T4 in uncontrolled studies we examined the effect of imipramine on serum thyroid levels in panic disorder patients in a double-blind placebo and diazepam treatment controlled study. 2. Treatment with imipramine (10 subjects) was associated with a significant decrease of T4 and FTI and treatment with diazepam (8 subject) was associated with a significant decrease of T4. However, there was no significant difference across treatment groups. 3. This finding suggests that previously reported decreases in thyroid hormones during antidepressant therapy may be due to nonspecific effects of treatment rather than to the drug itself.

Clomipramine test: serum level determination in three groups of psychiatric patients

Concentrations of clomipramine, a specific and potent serotonin uptake inhibitor, are measured in 67 psychiatric patients and 12 normal volunteers. The psychiatric patients are grouped according to the DSM III R criteria namely; pathological gamblers, obsessive compulsives and sufferers of panic disorders. Before and 30, 60, 90 and 120 min after an intravenous infusion of the drug (12.5 mg in 10 min), serum samples are collected to evaluate the concentrations of cortisol, prolactine and growth hormone. Simultaneously the clomipramine concentration of these samples is determined and these results only are reported in this communication. Very different drug concentrations are observed in individual patients receiving the same amount of drug, indicating a substantial inter-individual variability of drug metabolism. No statistical differences (Newman-Keules test) between the clomipramine concentrations from the patients of the three psychiatric groups and the normal group are observed. Neither are statistical correlations observed when clomipramine concentrations from all individuals (n = 79) are related with the age, sex or consumer behaviour (cigarette smoking, alcohol and coffee intakes) of the patients.