The utility of daily mood ratings in clinical trials of patients with bipolar II disorder

Abstract

Objective:

To demonstrate that there can be distinctive differences in information generated by standard interval measures as against using daily monitoring for evaluating progress in those with a bipolar disorder.

Method:

We undertook a 20-week study of individuals with a bipolar II disorder randomly assigned to receive either lamotrigine or lithium. Patients were rated on standard measures of depression and hypomania at monthly intervals, and they also completed a daily rating measure of their mood swings. We sought to demonstrate the potential for differing interpretations that emerge from these measurement strategies.

Results:

We graphed data for one subject who showed distinct improvement but demonstrated distinctly differing trajectories provided by monthly and daily data. In a second analysis, we considered sets of those who were judged as improving distinctly with lithium or lamotrigine to determine whether the drugs differed in speed of action, and again observed differing patterns between monthly and daily rating measures.

Conclusions:

A daily rating strategy appeared to provide additional and differing data compared to standard monthly measures. We therefore argue for the inclusion of daily mood ratings in clinical trials evaluating mood stabilisers and their use by clinicians in managing those with a bipolar II disorder.