How Do Anxiety and Depression Affect Social-Emotional Working Memory?

What you need to know

• The study examined brain activity during social-emotional working memory tasks in people with generalized anxiety disorder (GAD), major depressive disorder (MDD), and healthy controls.

• People with GAD showed altered activity in a brain region involved in integrating emotional and cognitive information, while those with MDD had changes in communication between brain regions that process emotions and direct attention.

• These distinct patterns of brain activity may help distinguish between anxiety and depression, which often have overlapping symptoms.

• The findings could lead to better ways to diagnose and treat these common mental health conditions.

How anxiety and depression affect our ability to process social and emotional information

Anxiety and depression are two of the most common mental health disorders, affecting millions of people worldwide. While they have some overlapping symptoms, they are distinct conditions. However, it can sometimes be difficult for doctors to distinguish between them, as many people experience symptoms of both anxiety and depression.

One way that researchers are working to better understand the differences between these disorders is by looking at how they affect cognitive functions like working memory - our ability to temporarily hold and manipulate information in our minds. In particular, scientists are interested in how anxiety and depression impact social and emotional aspects of working memory.

A recent study published as a preprint on medRxiv aimed to identify distinct patterns of brain activity related to social-emotional working memory in people with generalized anxiety disorder (GAD) and major depressive disorder (MDD). The researchers used brain imaging to examine neural activity while participants performed memory tasks involving emotional faces.

The social-emotional working memory task

The study included 25 people with GAD, 27 with MDD, and 29 healthy controls. All of the patients were experiencing their first episode of the disorder and had not yet received any treatment.

Participants completed a task while undergoing functional magnetic resonance imaging (fMRI) brain scans. The task involved viewing a series of faces showing different emotional expressions. There were two main conditions:

1. A low-demand task where participants had to indicate if the current face matched a target face shown at the beginning of the trial.

2. A higher-demand task where they had to indicate if the current face matched the one shown immediately before.

For each condition, participants sometimes had to focus on the emotion shown on the face, and other times on the identity of the face.

This task allowed the researchers to examine brain activity related to maintaining and updating social-emotional information in working memory under different levels of cognitive demand.

Key findings on brain activity

While the three groups performed similarly on the task, they showed some important differences in brain activity:

Altered activity in people with anxiety

Compared to the other groups, people with GAD showed an unusual pattern of activity in a brain region called the dorsomedial prefrontal cortex (dmPFC). This area is involved in integrating emotional and cognitive information.

Specifically, those with GAD had decreased dmPFC activity during the low-demand condition, but increased activity during the high-demand condition. This suggests they may have difficulty efficiently engaging this region to process social-emotional information, especially when cognitive demands are higher.

Altered connectivity in people with depression

In contrast, people with MDD showed differences in how the dmPFC communicated with another brain region called the insula. The insula is involved in detecting important or salient information in our environment.

Those with MDD had increased connectivity between these regions during the low-demand condition, but decreased connectivity during the high-demand condition. This altered pattern of communication may reflect difficulties appropriately allocating attention to social-emotional information.

Relationship to symptom severity

The researchers also found that across all participants, the strength of connectivity between the dmPFC and insula during the low-demand condition was related to the severity of depressive symptoms. This suggests this pattern of brain activity may be specifically linked to depression.

What do these findings mean?

This study provides evidence that anxiety and depression involve distinct patterns of disruption to brain systems involved in processing social and emotional information in working memory.

For people with anxiety, the key issue seems to be inefficient engagement of brain regions that integrate emotional and cognitive information. This fits with the tendency of people with anxiety to worry excessively and have difficulty controlling their anxious thoughts.

In depression, the main problem appears to be in how different brain systems communicate, particularly in allocating attention and cognitive resources to emotional information. This aligns with symptoms of depression like difficulty concentrating and a tendency to dwell on negative information.

Importantly, these distinct patterns emerged even though people with anxiety and depression performed similarly on the actual task. This highlights the value of looking at brain activity to understand the unique neurobiology of these conditions.

Limitations and future directions

There are a few important limitations to keep in mind:

• The study had a relatively small sample size, so the findings need to be replicated in larger groups.
• All patients were experiencing their first episode and were not taking medication, so it’s unclear if the same patterns would be seen in people with more chronic or treated conditions.
• The task focused specifically on facial expressions, so we don’t know if similar patterns would emerge for other types of emotional or social information.

Future research could address these limitations and also explore whether these distinct patterns of brain activity could be used to help diagnose anxiety versus depression, or to predict which treatments might work best for individual patients.

Conclusions

• People with generalized anxiety disorder show altered activity in brain regions that integrate emotional and cognitive information during social-emotional working memory tasks.

• Those with major depressive disorder exhibit changes in communication between brain areas involved in detecting important information and allocating attention.

• These distinct neural signatures may reflect core differences in how anxiety and depression affect cognitive and emotional processing.

• With further research, examining patterns of brain activity could potentially help improve diagnosis and treatment selection for these common and often overlapping mental health conditions.