Suicide Poses a Complicated Risk in Those with Infectious Diseases

A diagnosis of an infectious disease can be devastating for patients. Even as more effective treatments become available for infections such as HIV and hepatitis C, patients who receive a positive diagnosis must prepare for significant life changes and new burdens.

As physicians struggle to keep up with the latest treatments and therapeutic research, a growing body of evidence is highlighting another problem closely tied to infectious disease: suicide.

The first half of this month (June) was marked by a pair of high-profile suicides, prompting a national discussion about risk factors and prevention. When it comes to infectious diseases, suicide is a major problem, but one that is difficult to address because its cause is difficult to isolate.

“It gets very messy and hard to pinpoint an exact cause [of suicide],” said Travis Salway, PhD, a post-doctoral fellow at the University of British Columbia’s School of Population and Public Health and the British Columbia Centre for Disease Control.

The problem can be related to psychological and psychiatric factors, stress, pain, and chemistry. And sometimes, it can even be linked to the treatment for the underlying infection.

Though the issue is complicated, the statistics are clear. Salway’s research, which focuses on health disparities for LGBT individuals, found that nearly 1 in 4 (22%) gay and bisexual men who are HIV-positive reported suicidal ideation within the past year. Five percent of respondents to Salway’s survey reported a suicide attempt within the past year.

Another 2010 study found that although suicide rates dropped significantly among the HIV-positive population after the introduction of highly active antiretroviral therapy (HAART), the HIV-positive suicide rate was still 3 times higher than the general population.

However, the issue of suicidality among patients with infectious diseases is not just an HIV story.

Reports have shown increases in depression and suicidality among patients with hepatitis C (HCV) infections, and among those who received interferon therapy.

Contagion^® Editorial Advisory Board member, Robert C. Bransfield, MD, a psychiatrist who has studied links between infectious disease and suicidality, said interferon therapy marked something of a turning point. Although it didn’t cause depression or suicidality in every patient, the occurrence was significant enough to cause people to look more closely.

“You’re activating the immune system. Immune activation helps fight the infection, but immune activation can also alter neurochemistry and make people feel suicidal,” Dr. Bransfield said. “That was the first time there was a drawing of a connection that there’s something there.”

More recently, Dr. Bransfield has been studying the relationship between Lyme-associated diseases and suicide. Last year, he published a study estimating that at least 1200 people in the United States with Lyme-associated diseases commit suicide each year. That’s out of a total of 40,000 documented suicides (it is believed the number could be significantly higher if undocumented or poorly documented suicides were added).

Why the apparent link between infectious disease and suicidality, especially when HCV, HIV, and Lyme disease can all be treated with increasingly effective medications? Dr. Bransfield said there are multiple reasons.

In some cases, the issue may have to do with the stress of chronic pain, the potential to lose or miss work, or social stigma.

“That could be a psychological reason,” he said. “But separate and apart from that, there’s a physical thing that pushes people to suicide.”

In fact, a growing body of research has suggested that inflammation is linked to suicide.

“When you’re in a pro-inflammatory state, the risk of suicide is greater,” shared Dr. Bransfield.

Inflammation sets in motion a chain reaction, disrupting the kynurenine pathway, which leads to an increase in quinolinic acid.

“Quinolinic acid then works on the N-Methyl-D-aspartic acid (NMDA) site, and the NMDA site is a receptor in the nervous system,” he said. “When it hits that, it can make someone suicidal.”

That knowledge opens up significant new areas of research, but it also forces something of a change in the mentality of the medical community.

“It forces us to not be so fragmented within our specialty,” Bransfield explained. “Psychiatrists have to think of other specialties and general medicine and keep current, but so do infectious disease doctors. Infectious disease doctors can’t just view themselves as the authority in their field without thinking about how their fields connect to other fields, such as psychiatry.”

Aside from the physiological links between infectious disease and suicide, Dr. Salway said the issue is further complicated by the fact that many patients in some of the highest-risk categories have multiple risk factors for suicidality.

“We know that factors like loneliness or poor self-esteem, substance abuse, exclusion from your family, seem to be associated with the sexual behaviors that transmit HIV,” he said. “There tends to be a clustering of health problems.”

The idea that multiple risk factors are often at play, is known as syndemic theory. Proponents of syndemic theory argue for a more holistic approach and acknowledging that a patient may have had significant issues and risks for suicide and depression long before they actually contracted HIV.

The theory can be helpful for physicians because it emphasizes areas where they can make a difference.

“Unfortunately, in general practice even in high-risk populations, it’s remarkably difficult to identify people who are imminently suicidal,” explained Dr. Salway. “We don’t have the screening tools to know who needs to be provided immediate care.”

By thinking holistically, physicians can reduce the risk of suicide in HIV-positive patients by addressing other risk factors.

“The current recommendations are actually to bolster the options for things like substance use treatment, depression treatment—things that we know often go hand-in-hand with suicidality,” he said.

Whenever he presents his findings, Dr. Salway finds providers are eager to try and address the problem of suicidality.

“It’s not that they’re not concerned or compassionate about [suicide prevention among patients with HIV], and some are very well aware of it,” he said. “But, we do have a gap in telling physicians how to respond to it. That’s hard to do without better tools around suicide prevention, generally.”

In the clinic, Dr. Bransfield said physicians should not be afraid to ask patients about suicidality, something that often doesn’t happen.

“You don’t hurt anyone by asking,” he said. “You don’t plant the idea there.”

He added that physicians ought to do a better job of reading literature from other specialties. “I think it’s good for infectious disease doctors to brush up and get more current with their knowledge of psychiatry,” he said.

Another way to help, but one that requires resources from public health agencies, is better access to care. A 2017 study in The Lancet found HIV-positive men, in particular, are at a higher risk of suicide (twice the rate of the general population). However, the rate was 5 times higher during the first year after diagnosis, suggesting that treatment and the possibility of controlling the disease long-term can have a positive impact.

“These findings highlight the importance of prompt diagnosis and linkage to care as major public health interventions to reduce premature mortality,” wrote Sarah Croxford, MSc, of Public Health England, and colleagues. “HIV testing should be further expanded outside traditional settings to reach vulnerable populations and patients supported across the HIV care pathway.”

Dr. Salway added that support groups and community organizations can also play a role. HIV support groups, for instance, can help foster conversations about mental health, encouraging people to be more open about their struggles.

Though the challenge is complicated, Dr. Salway is gratified that people who know about the issue seem to want to fix it.

“I think people will start to push this along,” he said. “I’m optimistic.”