Patients suffering from stress-related psychiatric disorders such as depression, anxiety and panic attacks have been found to have a dysfunctional circuitry in the area of the brain responsible for suppressing memory.

Researchers used functional MRI (fMRI) to show how these people manage their traumatic memories and found that these memories are a source of anxiety to them because they are not being adequately suppressed by the brain but continue to interfere with the patients' lives.

fMRI were used to explore alterations in the neural circuitry that links the prefrontal cortex to the hippocampus while study participants were performing a memory task. The study included 11 patients with major depression, 13 with generalized anxiety disorder, nine with panic attack disorders, five with borderline personality disorder and 21 healthy individuals. All the study participants had experienced different stressful traumatic events, such as sexual or physical abuse, difficult relationships or "mobbing" at some point in their lives.

After reviewing a list of neutral word pairs, each participant underwent fMRI. During imaging, they were presented with one of the words and asked either to recall or suppress the memory of the associated word.

What the images showed was that the prefrontal cortex, which controls the suppression and retrieval of memories processed by the hippocampus, had abnormal activation in the patients with stress-related disorders in comparison to the healthy controls. While trying to suppress memories, patients with stress-related disorders showed greater activation in the hippocampus, suggesting that insufficient activation of the prefrontal cortex could be the basis for inadequate suppression of unwanted traumatic memories stored in the hippocampus.

The study suggests that the alteration of the prefrontal cortex may be making mechanism for memory suppression dysfunctional in patients with stress-related disorders. These patients often report having poor memory and problems concentrating, which might in part be attributed to this altered circuitry.