Marjolein Boshuisen

rCBF differences between panic disorder patients and control subjects during anticipatory anxiety and rest

BACKGROUND Our goal was to identify brain structures involved in anticipatory anxiety in panic disorder (PD) patients compared to control subjects. METHODS Seventeen PD patients and 21 healthy control subjects were studied with H(2)(15)O positron emission tomography scan, before and after a pentagastrin challenge. RESULTS During anticipatory anxiety we found hypoactivity in the precentral gyrus, the inferior frontal gyrus, the right amygdala, and the anterior insula in PD patients compared to control subjects. Hyperactivity in patients compared to control subjects was observed in the parahippocampal gyrus, the superior temporal lobe, the hypothalamus, the anterior cingulate gyrus, and the midbrain. After the challenge, the patients showed decreases compared to the control subjects in the precentral gyrus, the inferior frontal gyrus, and the anterior insula. Regions of increased activity in the patients compared to the control subjects were the parahippocampal gyrus, the superior temporal lobe, the anterior cingulate gyrus, and the midbrain. CONCLUSIONS The pattern of regional cerebral blood flow activations and deactivations we observed both before and after the pentagastrin challenge was the same, although different in intensity. During anticipatory anxiety more voxels were (de)activated than during rest after the challenge.

Five-minute recordings of heart rate variability in obsessive-compulsive disorder, panic disorder and healthy volunteers.

BACKGROUND Recent studies have used spectral analysis of heart rate variability (HRV) to study autonomous nervous system (ANS) function in panic disorder (PD). Most studies reported a reduced HRV in resting PD patients, suggesting increased sympathetic and decreased parasympathetic tone. In obsessive-compulsive disorder (OCD) inconsistent findings have been reported on ANS function and to date no studies have been carried out with spectral analysis of HRV. In this HRV study we compared ANS function in patients with PD, OCD and normal controls. METHODS Standardized HRV measurement was carried out in 24 PD patients, 26 OCD patients and 24 age-matched normal controls. All patients were drug free. As this comparison yielded unexpected results, the PD and normal control samples were enlarged to 53 and 54 subjects, respectively, to verify our first measurement. RESULTS OCD patients were not characterized by a reduced HRV, as compared to normal controls. This was also found in PD patients, even in the enlarged sample. CONCLUSIONS HRV analysis in patients with OCD or PD showed that these patients were not characterized by ANS abnormalities, as no evidence was found of diminished HRV in a large sample of resting OCD and PD patients, measured sitting on a hospital bed.

The effect of mirtazapine in panic disorder: an open label pilot study with a single-blind placebo run-in period

In this open label pilot study, we studied the efficacy of mirtazapine (Remeron) in panic disorder. Twenty-eight patients with a DSM-IV diagnosis of panic disorder, with or without agoraphobia (10 males/18 females), were included and 19 patients completed the study. The 15-week trial started with a 3-week single-blind placebo run-in period. After this run-in period, the 12-week active treatment phase started. As primary efficacy measures, we studied the decrease in the number of full symptom panic attacks and the number of patients completely free of panic during the last 3 weeks of the study. Seventy-four percent of the patients were considered responders, according to a decrease of at least 50% in panic attack frequency. All primary and secondary efficacy measures showed a significant improvement from the second week of active treatment onwards to endpoint. The main side-effects were different from the usual side-effects in selective serotonin reuptake inhibitors (SSRIs) (initial drowsiness, weight gain and pain in the legs). The results of this open label study in panic disorder suggest that mirtazapine seems to be a fast and effective treatment alternative for SSRIs in panic disorder.

Heart rate variability as predictor of nonresponse to mirtazapine in panic disorder: a preliminary study.

Using spectral analysis of heart rate, several studies have shown that panic disorder patients are characterized by a reduced heart rate variability (HRV), indicative of abnormalities in autonomous nervous system (ANS) function. We recently reported that patients with panic disorder, who did not respond to pharmacotherapy, were characterized at baseline by a higher heart rate. In this study, ANS functioning is investigated as a possible predictor of nonresponse to pharmacotherapy. Twenty-eight medication-free panic disorder patients entered a 12-week open-label treatment study with mirtazapine. Five-minute HRV recordings were obtained before treatment and were analysed using spectral analysis. The data of 17 patients could be used. The total spectrum and low frequency power of responders to mirtazapine were significantly higher than those of nonresponders. Our findings suggest that nonresponders to short-term mirtazapine treatment are characterized at baseline by a lowered output of the ANS. The results are preliminary in view of the small sample studied.