Mental health disorders are nothing to be ashamed of. They’re very common, and anybody can suffer from one.

Mental health disorders like anxiety, depression, and post-traumatic stress disorder (PTSD) are common, but aren’t completely understood. The public and even people whose job is to study mental health disorders don’t always understand what causes mental illnesses.

That’s why the study of mental illness is very important. It helps bring new understanding to how the mind functions when it’s healthy as well as when it’s unhealthy. Also, it can reveal patterns in mental illness that were previously unrecognized.

This can lead to better treatments, better coping mechanisms, and better understanding for people who are living with mental illnesses.

Overlapping Mental Illnesses

One thing that experts have known for a while is that certain mental illnesses overlap in various ways. Depression, anxiety, and PTSD all share some symptoms and elements of each can appear in the other.

For example:

• A person who is suffering from depression may also experience higher-than-normal levels of anxiety.
• A person who is suffering from PTSD may experience symptoms of depression.

These symptoms may or may not be signs that a person is suffering from more than one mental illness. But, it is possible to have more than one mental illness at one time. It’s not unusual for people to experience depression, anxiety, or PTSD together in some combination.

You might even experience two of these at once.

When two or more mental illnesses appear together, this is called comorbidity.

Neurological Similarities

Researchers understood that depression, anxiety, and PTSD may share neurological similarities. So, in 2019 they decided to study brain scans to find shared neural features.

They looked at more than 9,000 brain scans, including those with mental health disorders and a control group. In order to find similarities, researchers examined parts of the brain that were more active in people with mental health disorders than in the control group.

What they found confirmed the theory that depression, anxiety, and PTSD had neurological similarities – the brain scans of people with those illnesses showed brain activity that was consistent with the other disorders, but not with the scans of those who didn’t have any of those disorders.

One finding was that people suffering from mental illnesses had decreased activity in parts of the brain that are involved in stopping cognitive processes and switching to new ones.

In other words, people suffering from depression, anxiety, or PTSD were less able to turn off those thoughts and feelings and switch to different thoughts and feelings. The results of the brain scans showed that they also had trouble switching from one task to the next.

Feeling Locked In

People suffering from depression, anxiety, and PTSD often describe feeling locked in or stuck in both thought and behavior patterns. These brain scans could help understand why.

If you’ve ever experienced the feeling of not being able to stop thinking about something that made you sad, anxious, or afraid, and not being able to distract yourself, you can probably understand how being consistently unable to turn off those emotions or do something else to change your mood and thoughts could be disruptive and upsetting.

And if you’ve ever watched somebody keep repeating unhealthy behavior patterns, even when it was clear to you and to them that those behaviors would not achieve a desirable result, this research could help to explain why they continued to repeat those behaviors.

Anxiety and depression are similar, only instead of strictly sad thoughts, people with anxiety experience fear over and over again. And people with PTSD find themselves reliving a traumatic event over and over again, even years after the occurance.

The reason these thought and behavior cycles are so difficult to break is that the brains of those affected aren’t able to turn off  as easily as those with healthy brains.

Hyperactive Brain Regions

In the study, the brain regions associated with switching tasks and thoughts and turning off thoughts were less active in those with a mental illness than those of the control group.

However, while that difference was the most significant, it wasn’t the only one present. Other brain regions were hyperactive in the scans of the people with mental illness than in the control group.

The hyperactive regions of the brain included the anterior cingulate cortex, left amygdala, and thalamus. These regions of the brain process emotions, regulate emotional experiences, and form and retrieve emotional memories.

So, for example, because the brain of a person with depression or anxiety is spending more time on emotional memories than the brain of a person without those mental illnesses, it may be more difficult for that person to escape upsetting or depressing memories than it is for a person without mental illness.

Work is necessary to determine how useful the study information is and how it can be applied in therapeutic settings.

Information found in the study may not be useful in understanding mental illness in children because the participants were adults. But this information about the neurological connections between anxiety, PTSD, and depression does offer a path forward for new and improved treatments that target the specific areas of the brain affected by those illnesses.