Anxiety and depression are common emotional symptoms experienced by people with bipolar disorder. The coexistence of anxiety and bipolar disorder is estimated at 74.9%. Long-term studies have shown that individuals with bipolar disorder experience depressive symptoms about three times more frequently than manic symptoms throughout their illness.
Anxiety and depression can be associated with lower functioning, earlier onset of symptoms, reduced response to treatment, and an increased risk of suicide. It is important to understand how anxiety and depression interact with each other and which influences the other. However, we still have more to learn about the specific timing and relationship between anxiety and depression in bipolar disorder.
In light of this, Drs. Hanjoo Kim, Melvin McInnis, and Sarah Sperry analyzed data from 651 participants with various forms of bipolar disorder who had been assessed for at least five years in the Heinz C. Prechter Longitudinal Study of Bipolar Disorder. The researchers used an advanced statistical method called dynamic structural equation modeling (DSEM) which helps accurately study how things change over time.
The study results showed that people with bipolar disorder experience significant ups and downs in anxiety and depression over time, and these two symptoms affect each other. Interestingly, anxiety tends to increase the likelihood of subsequent depression more than the other way around. It is worth noting that in some individuals, like those who are older or have experienced the loss of a spouse or divorce, depression has a stronger influence on subsequent anxiety compared to younger participants or those who are single or married.
These findings suggest that reducing anxiety could potentially help prevent episodes of depression in individuals with bipolar disorder. This intervention might be particularly important for patients who do not respond well to antidepressant medications. Additionally, early interventions for depression could be beneficial for older patients and individuals who have experienced stress in their marriages.
The research team is deeply grateful to the participants of the Prechter Longitudinal Study of Bipolar Disorder. Without their invaluable contributions, these important insights would not have been uncovered.