I wanted to be a psychologist since I was a teenager, and I spent years pursuing that one goal. I opened my private practice as soon as I was licensed. It was a risky move, not getting a day job at a hospital or a clinic, but within one year, my practice was doing quite well and I was making more money than I ever made before. Of course, I was a full-time student my entire life. (Laughter) I could have worked at McDonald's and made more money than I ever made before. That one-year mark came on a Friday night in July. I walked home to my apartment and got into the elevator with a neighbor who was a doctor in the ER. The elevator rose, then it shuddered and stalled between floors. And the man who dealt with emergencies for a living began poking at the buttons and banging on the door, saying, "This is my nightmare, this is my nightmare!" And I was like, "And this is my nightmare." (Laughter) I felt terrible afterwards, though. Because I wasn't panicked and I knew what to say to calm him down. I was just too depleted to do it, I had nothing left to give, and that confused me. After all, I was finally living my dream, so why wasn't I happy? Why did I feel so burned out? For a few terrible weeks, I questioned whether I'd made a mistake. What if I had chosen the wrong profession? What if I had spent my entire life pursuing the wrong career? But then I realized, no, I still loved psychology. The problem wasn't the work I did in my office. It was the hours I spent ruminating about work when I was home. I closed the door to my office every night, but the door in my head remained wide-open and the stress just flooded in. That's the interesting thing about work stress. We don't really experience much of it at work. We're too busy. We experience it outside of work, when we are commuting, when we're home, when we're trying to rejuvenate. It is important to recover in our spare time, to de-stress and do things we enjoy, and the biggest obstruction we face in that regard is ruminating. Because each time we do it, we're actually activating our stress response. Now, to ruminate means to chew over. The word refers to how cows digest their food. For those of you unfamiliar with the joys of cow digestion, cows chew, then they swallow, then they regurgitate it back up and chew it again. (Laughter) It's disgusting. (Laughter) But it works for cows. (Laughter) It does not work for humans. Because what we chew over are the upsetting things, the distressing things, and we do it in ways that are entirely unproductive. It's the hours we spend obsessing about tasks we didn't complete or stewing about tensions with a colleague, or anxiously worrying about the future, or second-guessing decisions we've made. Now there's a lot of research on how we think about work when we are not at work, and the findings are quite alarming. Ruminating about work, replaying the same thoughts and worries over and over again, significantly disrupts our ability to recover and recharge in the off hours. The more we ruminate about work when we're home, the more likely we are to experience sleep disturbances, to eat unhealthier foods and to have worse moods. It may even increase our risk of cardiovascular disease and of impairing our executive functioning, the very skill sets we need to do our jobs well. Not to mention the toll it takes on our relationships and family lives, because people around us can tell we're checked out and preoccupied. Now, those same studies found that while ruminating about work when we're home damages our emotional well-being, thinking about work in creative or problem-solving ways does not. Because those kinds of thinking do not elicit emotional distress and, more importantly, they're in our control. We can decide whether to respond to an email or leave it till morning, or whether we want to brainstorm about work projects that excite us. But ruminations are involuntary. They're intrusive. They pop into our head when we don't want them to. They upset us when we don't want to be upset. They switch us on when we are trying to switch off. And they are very difficult to resist, because thinking of all our unfinished tasks feels urgent. Anxiously worrying about the future feels compelling. Ruminating always feels like we're doing something important, when in fact, we're doing something harmful. And we all do it far more than we realize. Back when I was burned out, I decided to keep a journal for a week and document exactly how much time I spent ruminating. And I was horrified by the results. It was over 30 minutes a night when I was trying to fall asleep. My entire commute, to and from my office -- that was 45 minutes a day. Totally checked out for 20 minutes during the dinner party at a colleague's house. Never got invited there again. (Laughter) And 90 minutes during a friend's "talent show" that, coincidentally, was 90 minutes long. (Laughter) In total, that week, it was almost 14 hours. That's how much "downtime" I was losing to something that actually increased my stress. Try keeping a journal for one week. See how much you do it. That's what made me realize that I still loved my work. But ruminating was destroying that love and it was destroying my personal life, too. So I read every study I could find, and I went to war against my ruminations. Now, habit change is hard. It took real diligence to catch myself ruminating each time, and real consistency to make the new habits stick. But eventually, they did. I won my war against ruminating, and I'm here to tell you how you can win yours. First, you need clear guardrails. You have to define when you switch off every night, when you stop working. And you have to be strict about it. The rule I made to myself at the time was that I was done at 8pm. And I forced myself to stick to it. Now people say to me, "Really? You didn't return a single email after 8pm? You didn't even look at your phone?" No, not once. Because it was the '90s, we didn't have smartphones. (Laughter) I got my first smartphone in 2007. You know, the iPhone had just come out, and I wanted a phone that was cool and hip. I got a BlackBerry. (Laughter) I was excited, though, you know, my first thought was, "I get my emails wherever I am." And 24 hours later, I was like, "I get my emails wherever I am." (Laughter) I mean, battling ruminations was hard enough when they just invaded our thoughts. But now they have this Trojan horse, our phones, to hide within. And each time we just look at our phone after hours, we can be reminded of work and ruminative thoughts can slip out and slaughter our evening or weekend. So, when you switch off, switch off your email notifications. And if you have to check them, decide on when to do it, so it doesn't interfere with your plans, and do it only then. Cell phones aren't the only way technology is empowering rumination, because we have an even bigger fight coming. Telecommuting has increased 115 percent over the past decade. And it's expected to increase even more dramatically going forward. More and more of us are losing our physical boundary between work and home. And that means that reminders of work will be able to trigger ruminations from anywhere in our home. When we lack a physical boundary between work and home, we have to create a psychological one. We have to trick our mind into defining work and nonwork times and spaces. So here's how you do that. First, create a defined work zone in your home, even if it's tiny, and try to work only there. Try not to work on the living room couch or on the bed because really, those areas should be associated with living and ... bedding. (Laughter) Next, when you're working from home, wear clothes you only wear when you're working. And then at the end of the day, change clothes, and use music and lighting to shift the atmosphere from work to home. Make it a ritual. Now, some of you might think that's silly. That changing clothes and lighting will convince my mind I'm no longer at work. Trust me, your mind will fall for it. Because we are really smart, our mind is really stupid. (Laughter) It falls for random associations all the time, right? I mean, that's why Pavlov's dog began drooling at the sound of a bell. And why TED speakers begin sweating at the sight of a red circle. (Laughter) Now those things will help, but ruminations will still invade. And when they do, you have to convert them into productive forms of thinking, like problem-solving. My patient Sally is a good example. Sally was given the promotion of a lifetime, but it came with a price. She was no longer able to pick up her daughter from school every day, and that broke her heart. So she came up with a plan. Every Tuesday and Thursday, Sally left work early, picked up her daughter from school, played with her, fed her, bathed her and put her to bed. And then she went back to the office and worked past midnight to catch up. Only, Sally's rumination journal indicated she spent almost every minute of her quality time with her daughter ruminating about how much work she had to do. Ruminations often deny us our most precious moments. Sally's rumination, "I have so much work to do," is a very common one. And like all of them, it's useless and it's harmful, because we'd never think it when we're at work, getting stuff done. We think it when we're outside of work, when we're trying to relax or do things that we find meaningful, like playing with our children, or having a date night with our partner. To convert a ruminative thought into a productive one, you have to pose it as a problem to be solved. The problem-solving version of "I have so much work to do" is a scheduling question. Like, "Where in my schedule can I fit the tasks that are troubling me?" Or, "What can I move in my schedule to make room for this more urgent thing?" Or even, "When do I have 15 minutes to go over my schedule?" All those are problems that can be solved. "I have so much work to do" is not. Battling rumination is hard, but if you stick to your guardrails, if you ritualize the transition from work to home, and if you train yourself to convert ruminations into productive forms of thinking, you will succeed. Banishing ruminations truly enhanced my personal life, but what it enhanced even more was the joy and satisfaction I get from my work. Ground zero for creating a healthy work-life balance is not in the real world. It's in our head. It's with ruminating. If you want to reduce your stress and improve your quality of life, you don't necessarily have to change your hours or your job. You just have to change how you think. Thank you. (Applause)