A positive attitude is important to overall health, but a new study suggests a bright outlook could play a major role in how someone handles cancer treatments.

Researchers from The Ohio State University Comprehensive Cancer Center say that patients who had psychosocial issues such as anxiety, depression, low optimism, or lack of social support before a hematopoietic stem cell transplant (HSCT) had a higher risk for hospital readmission and stayed longer when they were readmitted compared to those in better overall mental health.

The transplants are most commonly used in patients with blood cancers. Readmission after the procedure has been linked to poor quality of life and survival prospects.

The researchers say that mental health screenings should be performed before the procedure. It could provide at-risk patients with assistance prior to and after the procedure as a way to prevent readmissions.

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Distress takes its toll

Dr. Daniel Richardson, first author of the report, pointed out that the research looks into the effects of distress on patients with risk factors who undergo the transplant.

It did not examine if positivity would lead to better outcomes, he noted.

“We saw in our study that patients with depression, bipolar, or anxiety (as a group) were more likely to be readmitted to the hospital following HSCT than those who did not have these conditions, about 1.7 times more likely,” Richardson told Healthline.

HSCT is an intense process, especially for patients with psychosocial risk factors. About 35 to 40 percent of HSCT patients have a high risk for depression and anxiety after treatment, Richardson added.

A few studies have shown that HSCT patients with psychiatric or psychosocial risk factors are at a higher risk for psychological complications. This includes higher rates of depression, anxiety, and post-traumatic stress disorder (PTSD).

In fact, those experiencing PTSD were higher by 10 to 15 percent, Richardson added.

That literature is not as clear when it comes to outcomes, though. Some have shown poorer outcomes but others do not show a difference.

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Emotional health studied

The study focuses on HSCT patients, but what effects does our mental health have on other types of cancers, or cancer in general?

“There have been some studies showing that patients with depression and anxiety have worse overall outcomes in all types of cancer in general, and are at a higher risk of infection across the board, but understanding why they are at higher risk for infection is another issue,” Richardson said. “It is speculated that it has to do with cortisol and the influence of anxiety and depression raising cortisol levels and thus producing a relative immunocompromised state.”

The link between psychosocial risks and outcomes is clear, but the mechanism driving it is not, Richardson noted.

It’s not known to what degree emotional health impacts outcomes, which specific treatments are more effective, or which diseases put people more at risk, he added.

The American Cancer Society reports that personality traits have not been proven to cause cancer. There is no reason to think that emotions can cause or perpetuate cancer based on research of how cancer starts and grows, the ACS says.

The organization does advocate for support and therapy to help patients and survivors deal with the complex realities they face.

Read more: Another side effect of cancer: Suicidal thoughts »

Screening a useful solution

Dr. Charles L. Shapiro, co-director of the Dubin Breast Center at Mount Sinai Hospital in New York, said studies have shown that some outcomes have been worse for cancer patients who are depressed.

That is why his institution screens patients for depression and anxiety at the onset of cancer treatment in an effort to alleviate the depression and improve outcomes. Physical activity reduces the risks of depression and fatigue, which can also help.

“I believe there is a lot evidence suggesting that pre-cancer personality traits, coping skills, and resiliency affect an individual’s perception of side effects, quality of life, and even clinical outcomes,” Shapiro told Healthline.

The evidence is typically only based on data from one point in time.

Last year, a study was done on 12,700 New Zealanders who had breast and colon cancers. Of them, about 630 people had received psychiatric services. The researchers say that survival was worse in the group that had been treated for mental health, especially those with schizophrenia or bipolar disorder.

That’s not to say those issues are the sole cause of poor outcomes. Late-stage diagnosis, communication with clinicians, and comorbidities can be factors as well.

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Are we doomed?

Even if a person does have a mental health issue, studies have yet to definitively say that the cancer patient will experience a negative outcome from treatments.

For anyone going into cancer treatment, how well they take care of themselves plays a large role in outcomes.

Richardson said patients tend to benefit in general from social relationships and counseling, and should take steps to maintain and improve their emotional status.

“From what I have observed in over three decades of experience, mental health issues in themselves do not necessarily contribute to poorer outcomes,” Katherine Puckett, PhD, chief of the Division of Mind-Body Medicine at Cancer Treatment Centers of America, told Healthline.

People with pre-existing mental health issues may already have quality-of-life challenges —limited support and unhealthy habits, to name a few — that could make it more difficult to go through cancer treatment with optimal outcomes.

“The outcomes of people with mental health issues who are receiving psychological/emotional and concrete support may be as positive as those of anyone else,” Puckett said.

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Can positivity cure cancer?

There’s no proof that being positive can alter cancer’s progression, though studies suggest optimism boosts longevity and overall mental healthhr — something Puckett has witnessed in her work.

“People are often told that they have to be positive to get through cancer treatment,” she said. “While there may be health benefits to being positive, I have found … that it’s most helpful to make room for all feelings to be expressed.”

“So often I have heard a loved one say to a cancer patient who is crying, ‘Stop crying. You know you have to be positive,’” Puckett added. “However, when we make space for people to express all of their feelings, rather than bottling them up inside, it is then easier for them to be optimistic. It is OK to allow tears to flow — these can be a healthy release.”