Is Multitasking Real? The Hidden Cost of Multitasking at Work
By Dr. Andrea Zorbas, Psy.D.
If you end your workday completely exhausted but cannot point to one thing you actually finished, this article is for you. You answered emails during the meeting, kept the report open in another tab, and fielded messages in between. It felt like keeping up. It did not feel like the reason you were so drained.
So is multitasking real? For the kind of thinking most jobs require, the short answer is no. The brain does not run two demanding tasks at the same time. It switches between them, quickly enough that it feels simultaneous, and every switch has a cost. Understanding that cost changes how you think about work stress, and it points to a surprisingly simple place to start.
Why Multitasking Backfires
When you move from one task to another, your brain has to drop one set of rules and load another. Psychologists call this task switching, and its cost is measurable. In a well-known series of experiments, Joshua Rubinstein, David Meyer, and Jeffrey Evans found that people lost time on every switch, and the losses grew as the tasks became more complex. Meyer has estimated that these small costs can add up to as much as 40 percent of a person's productive time.
The time cost is only part of it. The organizational psychologist Sophie Leroy described something she called attention residue: when you leave a task unfinished, part of your attention stays behind with it. You open the next document, but a slice of your mind is still on the email you did not send. Do that across a dozen open loops and you are working all day with only a fraction of your attention available for the thing in front of you.
What Multitasking Actually Does to Your Stress
Most people assume their stress comes from how much is on their plate. In practice, a lot of it comes from how much is half done. An unfinished task does not sit quietly. Your brain keeps tracking it, which is why the half-written proposal surfaces in the shower or at 2 a.m. Psychologists have studied this tendency of incomplete tasks to stay active in memory for nearly a century, and it is one reason a scattered day feels heavier than a busy but focused one.
Split attention also keeps your nervous system in a low-grade state of alert. Every notification and every switch is a small demand for readiness. Over a full day, your body never gets the signal that it can settle. In my work with clients, I often hear the same description: "I'm tired in a way that a night off doesn't fix." That kind of tired is rarely about hours. It is about a nervous system that has been on call since morning.
This is where multitasking stops being a productivity question and becomes a burnout question. Chronic split attention is one of the quieter ways work stress builds, because it does not feel like stress in the moment. It feels like being efficient.
How to Stop Multitasking: A Step-by-Step Practice
Pick one task and name it. Before you start, decide on a single piece of work and say it to yourself in a sentence: "For the next twenty minutes, I am drafting the budget summary." Naming the task gives your attention a clear target and makes it easier to notice when you drift.
Close everything else. Shut the inbox, the extra tabs, and the chat window, and put your phone out of reach. The goal is not willpower. It is removing the cues that pull you into switching, so you are not spending energy resisting them.
Give it twenty minutes of full attention. Set a timer and stay with the one task until it goes off. When the urge to check something arises, notice it and come back. Afterward, compare how your body feels with a typical scattered stretch of work. Most people notice the difference right away.
When Focusing Feels Impossible
For some people, single-tasking is not just unfamiliar, it is uncomfortable. The quiet of one task can make anxiety louder, and switching becomes a way to stay one step ahead of worry. If closing your inbox brings a wave of dread about what you might be missing, that is worth noticing. It suggests the switching is serving an emotional function, not only a practical one.
It also matters whether your work environment allows focus at all. If your role genuinely requires constant responsiveness, the answer is not to blame yourself for being scattered. It may mean negotiating protected blocks of time, or recognizing that the job itself is generating more stress than your nervous system can sustain. And when difficulty focusing has been lifelong and shows up across every part of your life, it may be worth an evaluation for attention-related concerns rather than another productivity system.
Building Focus Over Time
Start smaller than you think you need to. Twenty minutes of real focus once a day is more useful than an ambitious plan you abandon by Wednesday. Attention, like any capacity, strengthens with practice.
Close loops before you open new ones. When you can, finish the small thing before starting the next. Writing down exactly where you left off on a larger task also helps, because it gives your brain permission to set it down for now.
Protect recovery as seriously as output. Focus depends on a nervous system that gets to settle. Breaks that actually restore you, and evenings that are not spent half working, are part of doing good work, not a reward for it.
Working with a Therapist
If your days leave you depleted in a way rest does not repair, it may be more than a scheduling problem. Our work stress and burnout therapy helps professionals understand what is driving the exhaustion and build a way of working they can sustain. You can also reach the therapists at Therapy Now SF directly. Free initial consultations are available.
Dr. Andrea Zorbas, Psy.D. | Licensed Clinical Psychologist | Founder & Clinical Director, Therapy Now SF
Dr. Zorbas is a licensed clinical psychologist (Psy.D.) and the founder of Therapy Now SF, a group practice in San Francisco, California specializing in anxiety, work stress, relationship challenges, and emotional regulation. She works primarily with professional adults navigating the intersection of career demands and mental health. Her clinical approach is grounded in cognitive behavioral therapy (CBT), mindfulness-based techniques, and evidence-based emotional regulation strategies.
Therapy Now SF is located at 582 Market St., Suite 1203, San Francisco, CA 94104.