NEW YORK (Reuters Health) — Feeling insecure in close relationships with others may take a toll on the immune system, preliminary research suggests.In a study of 61 healthy women, Italian researchers found that those who had difficulty establishing close, trusting relationships showed signs of weaker immune function. Specifically, lab experiments showed that the women’s “natural killer” immune system cells were less lethal compared with those from other study participants.

Whether this means they’re more susceptible to disease is unknown, and for now the answer to that question is a “very prudent maybe,” Dr. Angelo Picardi, the study’s lead author, told Reuters Health.

The findings, published in the journal Psychosomatic Medicine, are in line with research showing that chronic stress can impair immunity, and the extent of the impact may depend on how an individual perceives and responds to stress. In short, personality traits may affect immune function. The researchers looked at the trait known as “attachment insecurity”, characterised by difficulty trusting and depending on others, feeling uncomfortable with emotional intimacy or worrying about being abandoned by loved ones. A person’s “attachment style” forms in childhood, based on a child’s relationship with his or her parents. It affects and is further shaped by romantic relationships later in life, explained Picardi, a researcher at the Italian National Institute of Health in Rome.

So attachment style can be seen as a fairly stable trait that affects a person’s response to stressful events, according to Picardi. Attachment insecurity, he explained, affects people’s ability to regulate their own emotions.