Cancer doesn’t just take a toll on your body; it can affect your mental health, too. In fact, patients often experience post-traumatic stress disorder months after a diagnosis, according to a new report.

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Researchers from Malaysia recently conducted an experiment, published in the American Cancer Society journal, to determine the predictors of PTSD in adult patients with cancer.

To do so, they followed 469 people with various types of cancer. They then tested the participants for PTSD six months after diagnosis and again four years later.

They found that 21 percent, or one-fifth, of the group had PTSD six months later. Four years later, 15 percent still had it.

Furthermore, they discovered one-third of those initially diagnosed with PTSD had persistent or worsening symptoms four years later.

"Many cancer patients believe they need to adopt a 'warrior mentality,' and remain positive and optimistic from diagnosis through treatment to stand a better chance of beating their cancer," study author Caryn Mei Hsien Chan said in a statement. "To these patients, seeking help for the emotional issues they face is akin to admitting weakness."

Researchers hope to administer more studies to further investigate the long-term emotional effects of the disease. They also want to find other ways to help people combat PTSD.

“There needs to be greater awareness,” Chan said, “that there is nothing wrong with getting help to manage the emotional upheaval – particularly depression, anxiety, and PTSD – post-cancer."