Unusual Mood Stability in Patients Taking Lithium

The Visual Analogue Mood Scale (VAMS) was completed for 30 consecutive days by 124 psychiatric patients and 36 non-patients control subjects. The 64 euthymic manic-depressive patients on chronic lithium therapy had similar mean mood ratings to the non-patient controls, but had lower mood variability as measured either by standard deviation of the mood rating or by a measure of the mean successive differences between consecutive mood ratings (delta squared). This unusual mood stability appears to be an effect on lithium therapy. This study thus offers some empirical support for the 'mood stabilizer' psychological model of lithium's effects in patients. It is also noted that this effect may be perceived in well patients as an undesirable effect of lithium treatment.