When a crush becomes obsessive

Limerence is known to cause distress and disrupt productivity for sufferers, to the extent where limerent people might start to neglect themselves, says Tyndall. That could include neglecting eating, sleeping and personal hygiene, to not being able to hold down a job and neglecting other relationships with family, friends or siblings. “They tend to be stuck in the past, thinking about their previous interactions with the person, trying to ruminate and think about the meaning of that interaction,” he says. “Their thinking is totally and utterly caught up with the person, and it dominates their life so much, that there’s no room for anything else.”

This is what makes limerence different to infatuation, which is another component of romantic love, characterised by its overwhelming nature and intensity in the early stages of a romantic relationship. Infatuation occurs at the beginning of many romantic relationships, and usually lasts from around three to six months, or sometimes up to a year, Tyndall says. But “there’s usually nowhere near as many negative consequences for the person’s physical health and their mental health,” he says, whereas limerence is severely more intense. “When you’re infatuated with someone you don’t obsessively think about every single emotional cue where there’s eye contact or a raised eyebrow… You don’t tend to analyse the person’s body language quite at the same level of as a person who is limerent.”

Limerence is also somewhat different from romantic passion, researchers say. Romantic passion involves a longing for intimacy and closeness with another person, not only physical intimacy but emotional connection and emotional intimacy too – “to know and be known by that person”, says Kathleen Carswell, assistant professor in the psychology department of Durham University in the UK. However, “someone who is limerent not only feels strong desire for intimacy with that person but will ruminate obsessively over that individual”, she says.

Nevertheless, there may be some overlap between romantic passion and limerence, she suggests, as romantic passion can also have an obsessive, ruminating component and feel similar to an addiction. “Romantic passion has been found to operate on the dopaminergic or reward system of the brain and someone highly limerent or having high levels of the obsessive component might be thought of as someone who is addicted,” she says.