⚫︎"I'm Fine" Is Proof That Something Is Wrong
—Last time, you told us that an increase in mistakes is a sign of mental trouble. When a manager notices and speaks up, how does the person respond?
Kabasawa: They say, "I'm fine." Almost without exception. That's what makes this so tricky. When a manager asks, "You've been making a lot of mistakes—are you okay?" someone who can explain their situation—"Actually, we just had a baby and I haven't been able to sleep at night"—is showing evidence of metacognition, so there's not too much to worry about. But more than 90 percent of people say, "I'm fine, it was just a fluke, I'll work hard, thank you." When you get a response like that, you need to be on alert.
—We tend to assume that because they say "I'm fine," they must be fine.
Kabasawa: Letting it slide there is the worst possible pattern. The person's own words can't really be trusted. There's also a symptom called "putting on a front." The worse someone feels, the less they want others to know. So they deliberately force a smile and act cheerful. People whose minds are exhausted are especially prone to doing this in front of bosses and colleagues. "Putting on a front" only tires them further, yet those around them notice far less than you'd expect.
—Then what should we use as a clue?
Kabasawa: Look at information from sources other than the person themselves. Observe changes in their work; ask other colleagues. The key is not to judge based on the person's "I'm fine" alone.
⚫︎If You Notice at the "Brain Fatigue" Stage, You Can Recover in a Week
—Once mental health declines, is it hard to recover?
Kabasawa: There are various views on this, but in my experience, recovery takes about as long as the period before the person sought treatment. Someone who says "I've felt off for the past week or two" will improve considerably after a week of rest. In reality, though, when I ask "Around when did you start feeling unwell?" most people answer three months ago, or six months ago.
—Why do they endure it for so long?
Kabasawa: The more diligent and responsible a person is, the more they say they don't want to be a burden on the company. Even when they feel terrible, they refuse to give up and tell themselves to "somehow push through." That's exactly when they should rest. There's a saying, "strike while the iron is hot," and the same is true of the mind. When a bad state continues for about a year, the symptoms become "fixed." It's like leaving a fracture untreated so the bone fuses in the wrong shape—recovery becomes extremely difficult.
—So that turning point is crucial.
Kabasawa: That's where the concept I focus on—"brain fatigue"—comes in. Between health and illness there is a "pre-illness" stage, and in the mental world we call this brain fatigue. At the brain-fatigue stage, you can recover quickly just by sleeping soundly for a week. Start going to the gym and you'll be back to normal in a month—it's about that manageable. But between brain fatigue and illness, there is a "cliff."
—A cliff?
Kabasawa: Not a gentle slope—a cliff. Once you fall off it, climbing back up isn't impossible, but it becomes enormously hard. That's why noticing at the brain-fatigue stage is decisively important. Mental illness never strikes suddenly out of nowhere. Fatigue accumulates gradually, and over two months, three months, or even more than six, it develops into illness. If you notice at some point along the way and adjust your lifestyle, you can turn back before the cliff.
⚫︎Objective Data Doesn't Lie
—Can devices and data help with that early detection?
Kabasawa: I think they help a great deal. In the mental world, there has been almost no objective testing until now. We've had to gather information through conversation with the doctor and questionnaires, but the person can lie as much as they like. Someone who doesn't want to take time off says "I'm doing great," while someone who wants time off exaggerates and says "I feel terrible." But physical data, like sleep data, doesn't lie.
—So even people who don't want to talk about mental health find sleep easier to accept.
Kabasawa: That's the key. When someone is told, "You've seemed a bit down lately," they don't want to accept it. But when told, "Haven't you been a little short on sleep recently?" it's a physical fact, so they can accept it: "Yes, that's true." Objective data is impossible to deny. It can be the trigger for the person to notice, and for those who still won't rest, it becomes material to persuade them: "You really should see a doctor."
⚫︎So as Not to Miss the Turning Point
Behind the words "I'm fine," a serious SOS may be hidden. Dr. Kabasawa says the key to recovering from mental decline lies in "the timing of noticing." At the brain-fatigue stage you can bounce back in a week, but once you cross the cliff, recovery takes many times longer. Objective physical data can be a tool for pausing at that turning point. In the next installment, we ask about the daily habits that prevent mental decline before it starts—sleep, connection, and the power of putting things into words.
Profile
Shion Kabasawa (Psychiatrist, Author, Film Critic)
Born in Sapporo in 1965. Graduated from the School of Medicine at Sapporo Medical University in 1991 and joined the university's Department of Neuropsychiatry. From 2004, he studied for three years at the psychiatry department of the University of Illinois in Chicago. After returning to Japan, he founded the Kabasawa Psychology Institute in Tokyo. Under the vision of "preventing mental illness through the dissemination of information," he shares knowledge of psychiatry, psychology, and neuroscience in accessible terms through internet media. With more than twenty years of communication experience, he has built a combined following of over one million across multiple online platforms, including his email newsletter, X, Facebook, YouTube, and Instagram. Known as "Japan's most prolific output psychiatrist," he has written 55 books (as of 2026), including The Power of Output and The Power of Input (Sanctuary Publishing), a series that has sold more than 2.7 million copies in total.
