Background: To investigate whether patients with anxiety disorders have more variable mood than control subjects.
Methods: Twenty-eight patients with anxiety disorders and 28 controls were assessed with the State-Trait Anxiety Inventory-Trait form (STAIT), Beck Depression Inventory (BDI), Mood Disorder Questionnaire (MDQ), and TEMPS-A questionnaire for temperament. Participants used Visual Analogue Scales (VAS) to rate low, high and anxious moods, morning and evening, for 7 consecutive days. Mood variability was calculated with the Mean Square Successive Difference (MSSD) and the Standard Error of the Mean (SEM), both derived from the VAS ratings.
Results: (1) The MSSD and SEM measures for low mood and anxiety variability were higher in patients than controls. The SEM for high mood was marginally higher in patients. (2) The high mood measures separated into two clusters: (a) the mean of the VAS high mood scale and the TEMPS hyperthymia scale apparently measure an adaptive high mood or hyperthymia that did not correlate or correlated negatively with depression (BDI). (b) The MSSD of the VAS high mood scale, the TEMPS cyclothymia scale, and the MDQ correlated with each other and with the BDI as variable high mood that is distressing.
Limitations: Small sample size.
Conclusions: Patients with anxiety disorders show more mood variability than controls. We also found a difference in the measures of adaptive high mood from variable high mood, the latter associated with depression. Mood variability is an important but neglected aspect of distress in patients with anxiety disorders.