How Do Mood Swings Influence Perception in Bipolar Disorder?

Momentary mood swings, even those lasting only seconds, drastically affect the brain’s response to enjoyable events in persons with bipolar disorder, according to a new study conducted by UCL researchers.

The Influence of Mood Swings on Perception

Previous research has shown that mood swings can cause people to perceive situations in a more positive or negative manner, regardless of bipolar disorder. When we are in a good mood, we tend to view things more positively, allowing the good mood to spread and gain momentum. Conversely, when we are sad, we are more likely to see unfavorable outcomes as significantly worse, causing us to remain upset or become even more distressed.

Mood Momentum and Its Effect on Judgement

This “momentum” in mood can influence how we interpret situations and make decisions. Dr. Liam Mason, co-lead author from UCL Psychology & Language Sciences, explains, “Imagine going to a new restaurant for the first time. If you’re in a great mood, you’re more likely to think the experience is better than it is.”

Bipolar Disorder and Heightened Susceptibility to Mood Swings

A new study published in the journal Biological Psychiatry Global Open Science revealed that patients with bipolar disorder are more susceptible to mood swings and this mood bias. The researchers also uncovered the brain connections responsible for this effect.

Investigating the Brain’s Response to Mood Swings

In this study, the researchers examined what happens in the brains of people with bipolar disorder when they play a computerised Roulette game with both positive and negative outcomes. The team scanned the brains of 21 bipolar patients and 21 control subjects using functional Magnetic Resonance Imaging (fMRI). This technique allowed them to monitor participants’ brain responses during both victories and defeats.

Tracking “Reward Signals” and Mood Variations

Researchers examined how micro mood variations altered “reward signals” in the brain over the span of a few seconds. Using a computational model, they quantified the mood momentum felt by participants based on previous outcomes. They then investigated whether the brain was more responsive to consecutive wins during periods of upward momentum (a sequence of wins) or downward momentum (a sequence of losses).

Neural Activity in Response to Momentum

During upward momentum, both groups exhibited increased neural activity in the anterior insula, linked to temporary mood changes. Only the bipolar disorder group showed a stronger impact of momentum on their perception of subsequent wins and losses. Researchers observed heightened activation in the striatum, a brain region linked to pleasure, among patients with bipolar disorder.

Reduced Brain Connectivity in Bipolar Disorder

Importantly, the researchers found that patients with bipolar disorder had less connection between the striatum and anterior insula. Dr. Hestia Moningka explained that control group participants showed insula and striatum coordination, helping them manage mood during rewards. Participants with bipolar disorder struggled to separate their mood from the excitement of rewards during periods of high momentum.

The Vicious Loop of Mood Swings in Bipolar Disorder

Researchers believe these findings explain how bipolar disorder patients can get trapped in a vicious cycle of worsening mood. Dr. Moningka said these findings could lead to interventions that regulate mood without dulling exciting experiences.

New Interventions for Bipolar Disorder

Dr. Moningka explained they are exploring new interventions to help bipolar patients separate mood from perception and decisions. This could provide a more balanced approach to managing their emotional responses without compromising their ability to enjoy positive experiences.”