Most people feel angry or irritable at times, but frequent and severe irritability in the setting of someone with depression could mean that person may have a harder road to travel.
A new study looked at patients with depression to study how often they experienced episodes of irritability and anger and what, if any, outcomes this symptom had on the course of depression.
They found that people who feel very irritable during a depressive episode may be experiencing more severe depression. They also found that depressed people with irritability might be more likely to develop other mental illnesses.
These findings could affect how doctors monitor and treat depressed patients with irritability symptoms in the future.
Lewis Judd, MD, of the Department of Psychiatry of the University of California, San Diego, and colleagues conducted this study to see how common irritability was among individuals experiencing depression and if it was associated with other mental health issues.
Irritability and anger are already recognized as common symptoms of a major depressive episode, or a period in which someone experiences a severely depressed mood.
Previous studies have shown that anywhere from 37 percent to 46 percent of people with depression feel hostile or irritable during a major depressive episode. Younger people, women and people with more severe depression were more likely to report feeling irritable in those studies.
Some previous studies have shown evidence that irritability during a major depressive episode is associated with other mental illnesses, like anxiety. Dr. Judd's research sought to find out whether irritability in people during a major depressive period was linked to other illnesses, and if so, which ones.
The researchers used data collected by the National Institute of Mental Health Collaborative Depression Study. Participants in the Collaborate Depression Study, or CDS, were enrolled at five different academic medical centers across America beginning in 1978 while they were being treated for mental illness.
The researchers selected 536 participants who were experiencing a major depressive disorder, excluding bipolar disorder and schizophrenia.
The researchers asked these participants about the severity of their irritability and anger, from nonexistent or slight (occasional brief anger) to extreme (fits of violence).
During the intake survey, over half of the participants said they had experienced mild, moderate, severe or extreme irritability during their most recent major depressive episode.
The CDS followed up with participants for an average of 16.2 years, periodically asking them about their psychiatric status, any mental illness episodes, new diagnoses, suicide attempts and more.
The researchers found that 54.5 percent of the study participants experienced clinically significant irritability during their depressive episodes. Participants who reported irritability and anger were more likely to have more severe depression and a longer depressive episode than those who did not feel irritable and angry.
The participants who reported irritability also had problems with impulse control and were more likely to abuse drugs than those who did not report irritability. They also were more likely to develop anxiety disorders and antisocial personality disorders.
The participants who were more likely to become irritable during their depressive episodes did not have an increased risk of suicide attempts or more frequent depressive episodes.
The researchers suggested that people with irritability and anger during depressive episodes must be identified and closely monitored because their depression may be more complex, chronic and severe. They also suggest that depression with over irritability and anger may be a distinct subtype of major depressive disorder.
They concluded that more research needs to be done regarding people whose depression makes them irritated, as they may respond better to certain types of medication. Additionally, they said that those patients could benefit from treatment plans including anger management and impulse control strategies.
"We need to pay more attention to the anger, annoyance and irritability that comes with depression," said Shannon Kolakowski, PsyD, a licesned psychologist in private practice. "Irritability and quickness to anger are always red flags to me that someone is suffering.
"This research really supports the idea that people should view high irritability and hostility as sure-fire signs it's time to get help from a psychologist to treat their depression," Dr. Kolakowski said.
"Hopefully this research helps highlight the fact that even though irritability may not be the first symptom people associate with depression, it's an important sign to look for, not to be minimized or dismissed," she said.
This study was published in JAMA Psychiatry on September 11.
The funding source for the database was the National Institute of Mental Health. Several of the authors received compensation for presentations from various foundations and pharmaceutical companies. One author provided statistical consulting services to pharmaceutical companies.