A systematic review published in the journal Bipolar Disorder found evidence that the presence of anxiety disorders in childhood or adolescence increases patient risk for developing bipolar disorder (BD) later in life.
Investigators from King’s College London searched publication databases through September 2022 for longitudinal studies examining BD risk. A total of 16 studies comprising 21 reports with a total sample size of 2,433,761 study participants recruited from 10 countries were included in this review. The studies included patients who experienced anxiety in childhood or adolescence, as well as patients born to parents with bipolar disorder who also experienced early-life anxiety.
One study with 10 years of follow-up data for patients aged 14 to 24 years reported that the presence of obsessive-compulsive disorder and specific phobia increased the risk for BD onset by 590% and 120%, respectively. In addition, the study found a significant link between separation anxiety disorder and the later development of BD in a subsample of patients aged 14 to 17 years. The study included 4 years of follow-up data and reported that separation anxiety increased the risk for BD by 7-fold.
In addition, a study that employed a machine-learning approach using data from a large birth cohort reported that a diagnosis of suicidality, followed by generalized anxiety disorder by the age of 18 years were the first- and second-best predictors for BD risk, respectively.
In a study that assessed patients with hypomania spectrum episodes at ages 16 and 17 years, researchers found that the risk for developing BD at 15 years follow-up was associated with the presence of either a panic disorder or generalized anxiety disorder, either of which would increase BD risk by 12-fold.
In another study that examined the risk between anxiety and development of BD in patients aged 14 years, researchers found that the presence of any anxiety disorder was associated with an increased risk for BD. Similarly, in a birth cohort study, the presence of a prior anxiety disorder increased the risk for adult-onset BD by 10-fold.
In naturalistic studies, children of parents with BD were found to be at high risk for a range of affective disorders. This relationship was reported to be much higher for women than for men. In a cohort of children of parents with BD with an Amish background, predictors for transition to BD during follow-up included sensitivity by nature, anxiety or worry, and somatic complaints during childhood. In a separate Dutch study examining children of parents with BD, 13% of the population developed BD over a 12-year period. In addition, 53% of these patients had anxiety disorders as children.
Review authors noted that several studies included in their systemic review came to the conclusion that there was no evidence associating anxiety disorders with risk of mania or hypomania.
The limitations of this study included the heterogeneity in study designs and methodology, including anxiety assessment strategies, and the fact that all data were sourced from high-income countries. In addition, the authors note that due to the limited number of studies examining this risk, it is not feasible to address the high rates of anxiety comorbidity, nor was it feasible to examine the high impact this may have on subsequent risk of later mood disorders.
Review authors concluded, “[T]his review suggests that anxiety in childhood or adolescence increases the risk of later [BD] and may represent a clinically useful marker of vulnerability to major mood disorders in bipolar offspring. Our results also indicated that future research is warranted to explore the potential clinical utility of child and adolescent anxiety as an early intervention target for those at high risk of developing [BD].”
Buckley V, Young AH, Smith P. Child and adolescent anxiety as a risk factor for bipolar disorder: a systematic review of longitudinal studies. Bipolar Disord. Published online March 22, 2023. doi:10.1111/bdi.13322