By Emma M. Foy, CBC NewsHealth.caA new study published in the journal PLOS ONE has found that one of the key factors in determining the severity of depression is whether the person has a “pathophysiological” depression, which is defined as a psychological or physiological condition that has a profound impact on how the body functions.
The study was led by researchers at the University of Toronto and the University Health Network.
“One of the reasons why people with depression are at greater risk of developing an exacerbation of their symptoms, or worsening of their depression, is that they have a genetic predisposition to depression,” said Dr. Mireya Albrecht, lead author of the study.
“Our research suggests that there may be a genetic component to this susceptibility.”
The researchers studied 1,093 Canadian adults between the ages of 25 and 64.
The study found that there were a total of 516 cases of “depression-related exacerbation” — meaning that the person had multiple symptoms of depression and/or symptoms of an exacerbating condition, such as chronic fatigue, anxiety, panic disorder or post-traumatic stress disorder.
There were also 4,892 cases of depression-related “pathological” depression — meaning the person experienced symptoms that were more severe than those seen in “normal” people, but with no underlying cause for the symptoms.
“When we compared the prevalence of pathology to that of normal, we found that pathological depression was more common in people with a history of depression,” Albrech said.
“Pathological depression is defined by having symptoms that are more severe and severe symptoms,” she explained.
“That’s what we’re finding with this study.”
Albrecht said that while the number of people with pathological depression is higher, it is still lower than in the general population.
“There are so many people in Canada who are at risk for developing a pathological depression and yet there are so few who are diagnosed with a disease that they’re more likely to be at risk of worsening their symptoms or having a negative impact on their lives,” Albrich said.
The researchers also found that people with pathology were more likely than people without pathology to have an alcohol or drug use disorder.
“We know that people who have more of these conditions are at higher risk for suicide and are more likely overall to have a poor mental health outcome,” Albrowcht said.
“It’s the same for those who have other problems like depression, anxiety or bipolar disorder.”
“People who are depressed and anxious or depressed but not in a depressive state are at an increased risk for being more likely, in our study, to have problems in terms of substance use, in terms to have poor mental and physical health outcomes.”
Albrich added that the risk of being at risk should not be confused with the risk that someone will develop an exacerbated condition from a diagnosis of depression.
“The risk is more likely if you’re already at a higher risk, because your symptoms may be worsening,” she said.
While there are many different causes for depression, there is one common thread that connects all of them, she said, which could be a combination of factors, including:a) genetics, which may be passed down from parent to child;b) family history, such a history involving depression and anxiety or substance use;c) stressful life events, such being raised in an abusive home or having low self-esteem or having poor health.
Albrech suggested that a common factor may be genetics.
“It may be that people whose genes are affected by depression have more than one gene that may predispose them to depression or predispose to more severe depression, so it may be something in their genes,” she added.
“In terms of the underlying genetic cause, that may be one of many factors, but we have to take a look at other genetic factors that may contribute to this.”
The study also found evidence that depression has a genetic basis.
“These findings suggest that genetic susceptibility is a significant determinant of the onset of depression among Canadian adults,” Albrecht said in a news release.
“For this reason, it’s important to recognize that if a person is diagnosed with depression, we should seek out a mental health professional to help them with their depression.”
AlBRECHT added that she believes this study shows the importance of conducting genetic research to understand the complex mechanisms underlying depression.
However, she stressed that she and her colleagues cannot speculate about the mechanisms that contribute to the etiology of these disorders.
“All we know is that it is a very complex process,” AlBRECHTS said.
For more information on depression and research, visit www.canadafest.ca/diseases/psychiatric-disease/depression.html