This summer, doctors in Dundee, Scotland, diagnosed a 57-year-old man with an ailment that he said had damaged his work life and romantic relationships, and frayed the nerves of his family and friends: Chronic lateness.

"My family don't believe it and think I'm making excuses," the Scot told The Daily Mail at the time. "I've been late for funerals and slipped in and hid at the back of the hall. I arranged to pick my friend up at midday to go on holiday and was four hours late."

Of course, "sorry I'm late — I have chronic lateness disorder," is not going to fly at the office. First, it's not in the DSM5, the manual of psychiatric disorders U.S. doctors use to diagnose patients. And second, would you even want it to fly? The tardy guy who excuses himself with a doctor's note probably won't be a favorite among co-workers.

But while doctors seem to agree that "chronic lateness" is not in itself a disorder, they aren't so quick to brush it off, either. For those who are frequently late, it may be a symptom of a condition they can't entirely control.

Before you pull an extraocular muscle with an epic eye-roll, here are a few causes of chronic lateness, according to the pros:

Everybody knows at least one narcissist: He's arrogant, expects constant attention and admiration, thinks everyone is jealous of him, and lacks the ability to empathize with others. Chances are, he's probably often late, as well. In Psychology Today, psychology professor Susan Krauss Whitbourne explains how the inability to see the world through other people's eyes can result in lateness.

Let's take the example of people who are late in situations that inconvenience other people. The latecomers can see, from their own point of view, why they're late. They know that traffic was bad, that they had one last email to answer, or that they couldn't extricate themselves from a conversation. [Psychology Today]

She also explains how over time, lateness and narcissism can reinforce one another.

Over time, chronic latecomers may start to experience some benefits from their tardiness which only serves to strengthen their tendency to be late. This is how the narcissistic tendency to be late can develop. Like the actor who flounces in to occupy center stage in the middle of a crowded scene, the latecomer sweeps in and becomes the center of everyone's attention. The tendency is strengthened even further when the latecomer encounters no adverse consequences and when the situations require the individual to be there in order for things to start. [Psychology Today]

Adults with ADHD, especially women, show different symptoms from kids with ADHD. Rather than being fidgety and compulsive, adults are often disorganized, messy, scattered, forgetful, and introverted. Women with ADHD have likely "alternately been anxious or depressed for years," Ellen Littman, author of Understanding Girls with ADHD, told The Atlantic. "It's this sense of not being able to hold everything together."

You can see how this profile might include "poor time management skills." Psychologist Michele Novotni wrote about it in ADDitude Mag, a publication devoted to the disorder.

Time management is a big problem for people with ADD. Everyone is late on occasion, but many ADDers run behind schedule more often than not. They are late to meetings. They stand up their friends. They pick up the kids late from school. They leave others waiting as they scramble to finish last-minute tasks or find misplaced wallets, cell phones, or keys.

ADDers don't intend to be inconsiderate or disrespectful. But because of chronic tardiness, they're often perceived that way. That misperception is one of the reasons why people with ADD have trouble maintaining good relationships with friends, family members, and co-workers. [Attitude Mag]

Subconscious tics
In her book Never be Late Again, Diana DeLonzer lays out a few profiles of the always-late. Those who are "deadlined," she says, subconsciously seek out the rush of sprinting to get somewhere. The "producer," meanwhile, "gets an ego boost from getting as much done in as little time as possible."

DeLonzer says most chronically late people don't enjoy irritating their friends and colleagues. "There are many misperceptions about chronic lateness," she says. "While we often accuse tardy types of wanting attention or of needing to be in control, lateness usually has little to do with those factors."