What you don't know about the genetic coding behind bipolar disorder

Part of being human involves various, unpredictable shifts in our energy and activity levels, along with our general mood.

After all, we all have moments where our mood can change either at the drop of a hat or over a more gradual process, usually caused by and exacerbated by stress, anxiety and feelings of displeasure.

However, people diagnosed with bipolar disorder (BD) will commonly experience more intense and unusual shifts in their general mood, energy and activity levels, and the rudimentary ability to carry out everyday tasks. Evidently, BD is classed as a mental health disorder characterised by abnormal shifts between manic and depressive behavioural states.

It should also be noted that BD is very commonly misdiagnosed, and, in some cases, will even go unnoticed for several years after initial symptoms start to surface.

So how prevalent is bipolar disorder in today's world?

According to the Treatment Advocacy Centre, in 2020, an estimated 5.9 million adults aged over the age of 18 in the United States alone were found to be affected by severe bipolar disorder. An estimated 51 per cent of individuals with this condition were also found to be untreated.

Despite this high prevalence of BD, very little is known about the underlying environmental and genetic variables that cause bipolar disorder. However, the results of previous studies do indicate that bipolar is highly heritable.

This specific indication arguably served as the catalyst behind a recent study published in medRxiv, an online pre-print server devoted to health sciences.

To conduct the study, researchers evaluated data from the Amish-Mennonite Bipolar Genetics (AMBiGen) study, in order for the team to look into genetic continuity between categorical and dimensional BD models. Over 700 individuals (with roughly 200 having a categorical diagnosis of a major mood disorder) were included in the study, with each one being interviewed by a psychiatrist and asked to complete a form detailing their history of manic symptoms and related impairments.

The primary objective of the study was to validate mood disorder questionnaires (MDQ) as a dimensional assessment of BD, whilst allowing the researchers to gain insights into the genetic and environmental variables that contribute to the disorder's development. The MDQ served to assess three features: depressive symptoms, maniac symptoms and impairments.

Additionally, the researchers hoped that their findings would have an immense impact on how BD and associated diseases are diagnosed, treated and even prevented.

Genetic overlaps were closely observed between categorical and dimensional BD models among a family sample. Moreover, the participants diagnosed with BD possessed higher MDQ scores than those without a BD diagnosis, thus demonstrating MDQ as a reliable BD measurement criterion.

At the culmination of their research, the team discovered a credible continuity between categorical and dimensional models of BD across family samples, with the findings also suggesting that MDQs could potentially be a valuable tool for determining those at risk for developing BD or any other associated disorders.

With these results, this outcome may lead to an enhancement of precision when preventing, treating and diagnosing BD, with future studies focusing on the genetics of behavioural disorders potentially being able to benefit from the methods and findings from this particular study.