More and more go through severe mania, depression as BPD prevalence rises in SG

Bipolar disorder (BPD) has become more prevalent in Singapore, and with it is an increasingly common experience of more severe symptoms of mania/hypomania and depression, as reported in a study.

“These figures are accompanied by the fact that the vast majority of individuals with subthreshold BPD predominantly experience moderately severe clinical symptoms, high levels of impairment, and marked suicidality,” according to the investigators.

In a cohort of 6,126 individuals from the second Singapore Mental Health Study (SMHS; 2016–2018) who had been surveyed, the lifetime prevalence of bipolar spectrum disorder (BSD), BPD, and subthreshold BPD was approximately 3.1 percent, 1.6 percent, and 1.6 percent, respectively. The corresponding 12-month prevalence was 1.6 percent, 0.9 percent, and 0.7 percent. Younger adults, those who were divorced or separated, or were unemployed had greater odds of having lifetime BPD. [J Affect Disord 2020;274:339-346]

“As this is the first study that investigated the prevalence of subthreshold BPD in Singapore, a more conservative definition was adopted such that it is closer to the concept of bipolarity (presence of hypomania and a depressive episode),” the investigators said, emphasizing that the lifetime and 12-month prevalence estimates could be higher if a broader definition were adopted.

“These findings therefore show that subthreshold BPD is not only clinically significant but also cross-culturally valid in a multi-cultural setting,” they added.

In terms of comorbid conditions, the proportion of individuals who reported lifetime comorbidity with at least one other psychiatric condition was 52.7 percent in the BPD group, 45.0 percent in the BSD group, and close to 40 percent in the subthreshold BPD group. Obsessive-compulsive disorder was the most common comorbidity overall, followed by alcohol abuse and general anxiety disorder.

Meanwhile, physical comorbidity was reported in 51.2 percent of individuals with BSD, 63.7 percent of those with BPD, and 38.6 percent of those with subthreshold BPD. Chronic pain was the most common comorbid physical condition in the first two groups but not in the third group.

Relative to estimates from the SMHS 2010, the current data reflected a higher number of individuals with 12-month BPD who had severe mania/hypomania (41 percent vs 10 percent). Also, more patients experienced a greater severity of major depressive episodes in the recent years (moderate: 23 percent; severe: 66 percent) than in the past (moderate: 40 percent; severe: 41 percent). [J Affect Disord 2013;146:189-196]

“One crucial reason underlying this rise is that a vast majority of those with BPDs do not seek treatment for their condition… These marked increases in severity and impairment are concerning and demonstrate an urgent need for screening, detection, and, ultimately, intervention for these affected individuals,” the investigators said.

Singapore ranks among the most stressed and overworked cities globally. Stress, if mediated by an already compromised hypothalamus-pituitary-adrenal (HPA) axis, may induce a dysregulation of cortisol levels, which in turn could increase the risk of bipolar disorder. [http://http//getkisi.com/work-life-balance#table; http://http//todayonline.com/big-read/big-read-short-singapore-workaholic-nation; http://https//www.todayonline.com/singapore/sleep-deprived-singaporean-workers-among-most-stressed-globally-survey; Bipolar Disord 2010;12:77-86; Psychol Med 2011;41:2447-2457]

The investigators acknowledged that the present study relied on self-reported data, which might be subject to unintended response biases. Additional research is needed to expand understanding of subthreshold bipolarity and BSDs in Singapore.