Nana warned us many a time not to go to bed on an argument. Don’t sleep in anger.

It turns out there’s a lot more to this advice than just an old wives tale. According to new research, sleeping when angry after an argument can have detrimental effects on a relationship. A study published in the Journal Nature Communications, examined the long term effects of sleeping after a negative experience. The study found that basically, when you sleep, your brain reorganises the way negative experiences are stored and makes them harder to forget. So if you go to sleep angry, chances are you will wake up angry and find it much harder to let go. According to the Guardian, during the study, researchers used MRI scans to show that “overnight memories” were distributed more evenly across the participants’ cerebral cortex than same-day memories. This means it would be harder for people to “unpick” the overnight memories in future. Worse than simply not being able to forget, a failure to suppress unwanted memories has been linked to symptoms in a number of psychiatric disorders including the ruminative state found in depression and intrusive memories in posttraumatic stress disorder (PTSD).