Changes in appetite and weight during the pharmacological treatment of patients with panic disorder

Antidepressants reportedly increase appetite, carbohydrate craving and weight in some patients with depression and panic disorder. This paper presents the results of changes in appetite and weight in patients with panic disorder treated with imipramine, diazepam or placebo in a double-blind prospective study. Forty-four patients with panic disorder were randomly assigned imipramine, diazepam and placebo. The investigators monitored weight and the patients rated their appetite and cravings during the eight week study. No significant increases in weight or appetite were found in the patients with panic disorder patients.

Effect of imipramine treatment on heart rate variability measures

Recently, heart rate (HR) variability has received considerable attention, and a decreased HR variability has been linked to a significant risk of cardiovascular illness. We have previously reported such a decreased variability in panic disorder patients. In this study, we report on HR variability in 12 depressed and 6 panic disorder patients at baseline and 1 and 3 weeks of treatment with imipramine as measured by the standard deviation, mean consecutive difference and the standard deviation of the mean consecutive difference of the R-R intervals in supine, supine deep breathing and standing postures. In all subjects, imipramine (mean dose: 70 mg/day) produced a significant decrease in heart rate variability at week 3 as measured by the above variables. This decrease in HR variability during imipramine treatment is probably due to its anticholinergic effects.

Heart rate and blood pressure: significance of the law of initial values

Thirty normal controls, 30 panic-disorder patients and 19 depressed patients participated in a study involving postural and isometric handgrip tests. Prestimulus values of heart-rate and blood-pressure were correlated with stimulus phasic responses. The law of initial values did not hold during the change from supine to standing posture or during the isometric handgrip test for heart-rate and blood-pressure, but it held for heart-rate during the change from standing to supine posture. The effect of regression toward the mean was accounted for in the analyses.

Decreased R-R variance in panic disorder patients

To investigate autonomic function in panic disorder patients (n = 30), we compared postural changes in heart rate and the R-R interval variance in patients and normal controls (n = 20). There was no significant difference in the immediate changes in heart rate upon standing between the groups. R-R variance was significantly decreased during resting supine condition in patients as indicated by the corrected standard deviation of the R-R intervals. The standing R-R variance was significantly lower than that of normal controls as indicated by the corrected standard deviations, the corrected mean consecutive difference and the corrected standard deviation of the mean consecutive difference of the R-R intervals, suggesting an increase in vagal withdrawal in patients, especially upon standing. If this finding is specific to panic disorder patients, it may be a useful peripheral marker for this condition.