Dynamical Patterns in Bipolar Depression

We examined dynamical patterns in the course of bipolar depression. We interviewed 55 individuals with bipolar I disorder using Modified Hamilton Rating Scale for Depression (MHRSD) for at least 20 months. Using a recently developed methodology, we categorized the level of instability and the nature of attractor patterns for each individual. Instability was related to the lifetime severity of depression as well as suicidality during the follow-up period. Individuals varied from 0 to 2 in the number of attractors. Relatively few individuals displayed only one attractor that fell within a depressive range; the most common patterns were instability and two attractors. Limitations and implications of these results are discussed.