It does not and they have not.

But the way in which these factors interact with one another makes it difficult to disentangle the effects of loneliness from the causes, cautions cognitive neuroscientist Livia Tomova at Cardiff University, UK. Do people’s brains start functioning differently when they become lonely, or do some people have differences in their brains that make them prone to loneliness? “We don’t really know which one is true,” she says.