This is a great article about a counter intuitive phenomenon. How can you want to fall asleep when you are clearly upset. Mr. Wolfson explores the possible psychological and biological explanations in this article.

Fight or flight, or sleep

Last month, my wife and I found ourselves in a disagreement about whether or not our apartment was clean enough for guests—the type of medium-sized disagreement that likely plagues all close relationships. In the midst of it, there was a lull and, feeling exhausted all of a sudden, I got up and left the living room. In the bedroom, I immediately fell face down into the sheets. The next thing I knew it was 20 minutes later and my wife was shaking me awake. I hadn’t meant to fall asleep; I just felt so fatigued in that moment that there was nothing else I could do.

This wasn’t new for me. A few weeks earlier, I had come into conflict with an acquaintance over some money. We were exchanging tense emails while I was at my office, and I began to feel the slow oozing onset of sleep, the same tiredness that came on when, as a child, I rode in the backseat of the car on the way home from some undesired trip. A sleepiness that overtakes the body slowly but surely and feels entirely outside of your control.

Though this has happened many times before, my response to conflict still seems strange to me. After all, as everyone knows from 9th grade biology class, when faced with stress—an acute threat—our bodies enter fight-or-flight mode. It’s supposed to be automatic: the adrenal cortex releases stress hormones to put the body on alert; the heart begins to beat more rapidly; breathing increases frequency; your metabolism starts to speed up, and oxygen-rich blood gets pumped directly to the larger muscles in the body. The point is to become energized, to prepare to face the source of the conflict head on, or, at the worst, be ready to run away, at top speed.

Of course, you don’t actually want the stress response system to be too reactive. If you were constantly in fight or flight mode, constantly stressed, it could actually have long-term effects on your neurochemistry, leading to chronic anxiety, depression, and, well, more sleeplessness. Even so, it seems like a good idea to sometimes be on high alert when dealing with stressful situations.

But that’s not what my body did. My body shut down.

If, during early development, a living thing comes to understand that it is helpless, it will continue to perceive a lack of control, no matter if the context changes.

I asked around, and found out that many others experience the same thing. For example, Dawn, a family counselor in Columbus, Ohio, told me that her husband Brad often “starts yawning in the middle of heated discussions, and will even lie down and go right to sleep.” One time their toddler son fell down the stairs (he was fine), and Brad left the room and went to bed. Brad has had this kind of stress response for all 24 years of their relationship; Dawn says she’s used to it by now.

Even though dozens of people told me similar stories, I began to wonder what was wrong with us—what was wrong with me. Why was my body, in the face of conflict, simply acquiescing? Where was the fight in me?

There’s a concept in psychology called “learned helplessness” used to explain certain aspects of depression and anxiety. It’s fairly old, having been firstrecognized and codified in the 1970s, but has remained largely relevant and accepted within the field. The name (mostly) explains it all: If, at a very early stage in development, a living thing comes to understand that it is helpless in the face of the world’s forces, it will continue to perceive a lack of control, and therefore actually become helpless, no matter if the context changes.

In the early studies, dogs were divided into two groups: The first half were subjected to electric shocks, but were given a way to stop the shocks (they just had to figure it out themselves). The second group of dogs received shocks but had no way to avoid, escape, or stop them. The experience, sadly, had long-term effects on the animals. When faced with stressful environments later on in life, the first group of dogs did whatever they could to try to deal with it; the second group simply gave up. They had been conditioned to respond to stress with acquiescence.

This type of learned helplessness isn’t limited to animals; many of the adults I spoke with all mentioned childhood anxiety stemming from uncontrollable situations.

“When I hit high school and stress levels became higher in my life (messy divorce between my parents and lots of moving), I began escaping into sleep,” says LeAnna, a 25-year-old from Washington state. “As an adult, I still have ‘go to sleep’ impulses whenever I feel overwhelmed.” Daniel, from Baltimore told me that “whenever there was any kind of ‘family strife’ I would just go to my room and sleep.” Daniel is now 51, and starts yawning any time he encounters a stressful situation.

"Our feelings are always in the past. This is something that's really outlived its adaptive value."

My parents divorced by the time I hit high school, but before they did, they fought a lot, usually in the kitchen beneath my bedroom. What I remember feeling most was powerlessness—not anger or sadness, but a shrug-your-shoulders, close-the-door, shut-your-eyes type of response because what was I going to do? Tell them to break it up?

That coping mechanism worked for me back then. I was able to compartmentalize those stressful experiences and move on with my life. I stayed in school and kept my grades up; I had friends and was relatively well-rounded. Things went well. But now, at 28, I still deal with interpersonal conflict by shutting the door and going to sleep. I act on feelings that are no longer relevant to the situation.

“Our feelings are always in the past,” says John Sharp, a psychiatrist at Harvard Medical School. “This is something that’s really outlived its adaptive value.” As an adult I should have control over my current situation, but I don’t. Am I like those lab dogs, shocked into helplessness?

At first glance, sleep might seem like quintessential avoidance, like burying your head in the pillow is no better than burying your head in the sand.

But I don’t feel as though I am not helping myself. After all, going to sleep isn’t like turning the lights off; the truth is that there’s a lot still going on while your eyes are closed. While we might be able to temporarily stave the flow of conflict by falling asleep, we’re not really escaping anything. In fact, sleep in some ways forces us to not only relive the emotional experience but to process and concretize it—by going to sleep I may be making the fight with my wife more real.

If you’re like me, you probably imagine memories work pretty simply: you have an experience, it gets stored somewhere, and then you retrieve it when you need it. But that leaves out a key step, memory consolidation, and that’s where sleep comes into play.

Here’s how it really works, according to Dr. Edward Pace-Schott, professor at Harvard Medical School’s Division of Sleep Medicine: When an experience is initially encoded as a memory, it rests in the brain’s short term storage facilities, where it is fragile, easily forgotten if other experiences come along quickly. In order for the experience to last, it needs to go through a process of consolidation, where it becomes integrated into other memories that you have. That’s why when you think of, say the 1993 baseball game between the Yankees and Orioles, you also think of bright green grass, the smell of peanuts and beer, your dad, and Bobby Bonilla, and not thousands of random bits and pieces.

Of course, not every experience is worth remembering. Only the highly intense experiences—positive or negative—are prioritized for storage later on. “Emotions put a stamp on a memory to say ‘this is important,’” says Pace-Schott. It makes sense: the color of the grocery store clerk’s shirt is significantly less essential than, say, your mother’s birthday.

If we didn’t shelve our memories appropriately, everything would be a jumble, and without consolidation, we would forget it all. Life would have no meaning, and more importantly (at least from an evolutionary standpoint) we would never learn anything—we’d be helplessly amorphous, easy prey.

"You can be driven to sleep simply by having a lot of emotional memories to process."

Here’s the conundrum, though: the same experiences that are stamped as emotionally important can overwhelm your brain’s short term storage facilities. Dr. Rebecca Spencer, a professor at the University of Massachusetts Department of Psychology, likens it to a desk where “whatever is stressing you out is this big pile of papers, but there are also other memories piling up on you.” With more and more papers landing in front of you all day, you’ll never effectively get to them all. And emotionally rich experiences are all high priority messages, screaming to be dealt with right away. So what happens next?

“You can be driven to sleep simply by having a lot of emotional memories to process,” says Spencer. It takes sleep to provide the space needed to sift through the days’ experiences, and make permanent those that matter.

Studies show that sleep enhances your memory of experiences, and the effect is multiplied for experiences with the stamp of emotion. In fact, the memory-consolidation process that occurs during sleep is so effective that some scientists, including Pace-Schott and Spencer, have suggested that it could be used to treat PTSD. Spencer posits that keeping someone from sleep following a traumatic event could be good in the long run. “If you force yourself to stay awake through a period of insomnia,” Spencer says, “the [traumatic] memory and emotional response will both decay.”

On the flip side, when it comes to the majority of the negative things we experience in life—the things that aren’t necessarily traumatizing like, say, a fight with your significant other—we want to go to sleep, because that protects the memory and emotional response.

And Pace-Schott points out that sleep disruption may prevent consolidation of potentially therapeutic memories, sometimes termed 'fear extinction' memories. These are memories that can dull the effect of a traumatic experience by creating more positive associations with specific triggers.] This means that improving sleep quality following traumatic events may be crucial to preventing PTSD.

The nap following a fight with my wife should, ideally, teach me how to better manage interpersonal conflict.

Ever wonder why little kids nap so much? Researchers believe that it’s not just because they’ve been running around all day—it’s also due to the fact their short-term memory storage space is so small, and they constantly need to unload experiences and consolidate memories more often. One recent study, in fact, found that “distributed sleep” (a.k.a. napping) is critical for learning at an early age. The nap that follows a 4 year-old child getting burnt on a hot stove should help him learn from the experience.

Similarly, the nap following a fight with my wife should, ideally, teach me how to better manage interpersonal conflict. The benefits of sleep on memory don’t go away.

When we wake up from sleep, we feel different. It's not just that time has passed; we've undergone a real chemical response. When we sleep, all the stress systems in our body are damped down, letting it relax, so that tenseness you felt, the sickness in your stomach, the frayed nerves, will all be gone in the morning. “It’s almost like we are different people when we wake up,” says Pace-Schott.

One particular neurochemical, called orexin, may hold the key to the puzzle. Orexin, which was discovered only about 15 years ago, is unique in that it plays a very clearly defined dual role in the body. First and foremost, it’s a crucial element in your daily sleep/wake rhythm. You get a boost of the stuff when you wake up, and it drops before you go to sleep. Studies in rats show that if you take all of an animal’s orexin away, it can no longer effectively control sleeping and waking. Since its discovery, orexin has become one of the key diagnostic criteriafor determining narcolepsy—those with the sleep disorder essentially have none of the neurochemical.

And then there’s the second function: It’s part of the stress response system.

“The orexin system is absolutely hardwired into the sympathetic nervous system,” says Philip L. Johnson, a neuroscientist at the Indiana University School of Medicine. If everything is working normally, when you are faced with a stressful situation, your orexin system kicks in and triggers the stress responses that you expect: fight or flight.

In other words, the same exact neural pathway that handles wakefulness (we can’t even get out of bed without orexin kicking in) also handles a key aspect of our stress response.

Think about this: while narcoleptics do sometimes just nod off randomly, strong emotions are, most often, connected to onset of sleep. It’s counterintuitive, but it’s true, says Johnson. For many narcoleptics, strong emotions associated with stress can cause a complete collapse.

Of course, this should sound familiar—it’s not so different than what happens when Brad, LeAnna, Daniel, I, and so many others go head to head with stress. The science on this is still in its infancy, and it remains unclear exactly what’s going on at a chemical level here, but there does seem to be some connection.

In the meantime, sleep doesn’t seem too bad. The problem may still be there when you awake, but you’ll have a better understanding of it, and hopefully, a clear slate to handle it.