There’s nothing inherently wrong with daydreaming.

Letting your thoughts wander through imaginary worlds can provide a much-needed distraction from the stresses of life, regulate emotions, foster creativity, or simply ward off boredom.

But as the BBC reports, a condition called maladaptive daydreaming can effectively trap certain people inside extensive fantasies for days at a time — doing more harm than good by adding, instead of taking away, from all that stress.

Maladaptive daydreaming, a condition that affects anywhere from two to four percent of the adult population, “causes distress and it interferes with your ability to function,” psychiatrist and author Colin Ross told the BBC. In extreme instances, people can be trapped inside their daydreams for up to 12 hours a day.

“When they eventually snap out of a daydreaming episode, maladaptive daydream sufferers tend to experience their fantasies as futile, and a waste of time,” Ross explained. “Yet the addictive nature of it means that the cycle continues — it is one that is hard to break.”

One woman who suffers from the condition told the BBC that she used her daydreams as a “safe place” where “nobody teased me” as a child. Another woman described her daydreams as a “kind of parallel world” that was disruptive enough to interrupt her studies at a young age.

The term “maladaptive daydreaming” was first coined by University of Haifa, Israel, clinical psychology professor Eli Somer in the early 2000s. It describes a condition that involves spending excessive amounts of time daydreaming, frequently turning the otherwise harmless practice into an unhealthy attempt to cope with a pre-existing problem.

As a result, some who suffer from the condition withdraw from their social lives and become increasingly isolated, triggering feelings of shame and regret.

Scientists have found intriguing links between maladaptive daydreaming and those suffering from developmental trauma or diagnosed as being on the autism spectrum. Some researchers have also found links to similar compulsive disorders, like OCD and ADHD.

“With ADHD, the overlap is especially important because excessive fantasy can look like inattention from the outside,” Somer told the BBC. “With OCD, there are shared features such as intrusiveness, compulsivity, and difficulty disengaging.”

It’s important to note that maladaptive daydreaming has yet to be added to the Diagnostic and Statistical Manual of Mental Disorders, or DSM-5, a widely used taxonomic tool published by the American Psychiatric Association that standardizes the classification of mental health disorders.

Regardless, scientists are working on establishing new ways to address it through clinical treatment in a broader effort to help patients regain control — not dismiss their daydreaming entirely.

After all, there’s plenty to gain from daydreaming in its non-addictive, self-regulated form.

More on mental disorders: Psychologist Says AI Is Causing Never-Before-Seen Types of Mental Disorder