What to write in a mood diary
Most people give up because they are trying to write feelings. Write the boring things instead.
Most mood diaries are abandoned in the first fortnight, and almost always for the same reason: people think the job is to describe how they feel.
So they open it, find that today feels like nothing in particular or like everything at once, cannot produce a paragraph worthy of the occasion, and close it again. Two weeks later the empty diary has become one more piece of evidence that they cannot do things properly.
The fix is to write the boring things instead.
Why the boring things are the useful ones
A diary has one job: to tell you, in six weeks' time, something your memory will not.
Memory is unreliable here in a specific way — mood colours recall, so on a bad day you remember a bad month, and last week gets repainted in today's shade. That is why “how have you been?” is such a hard question to answer honestly, and why a diary is worth keeping at all.
What actually survives that distortion is not your description of Tuesday. It is the small factual stuff: whether you left the house, whether you ate, whether you slept, whether you answered anyone. Those are checkable, they take four seconds to record, and they are what a pattern is made of.
Five things worth recording
A number. Any scale. One to five is plenty. It does not need to be accurate — it needs to be consistent, because you are comparing it against your own past entries, not anyone else's.
Sleep. Roughly how long, and whether it was any good. This is the field most likely to explain everything else, and the one you will most regret not having.
Did you leave the house. Yes or no. Unglamorous and remarkably informative over a month.
Did you speak to anyone. Same.
One line about the day. Not a reflection. A fact. “Work was bad.” “Slept in until two.” “Went to Mum's.”
And if you are on medication, one more that matters more than the rest combined: note the date anything changes. A dose going up, a new tablet, a missed few days. Almost every question you will be asked later is secretly about timing, and this is the field that answers it. Keeping track of medication changes goes into why.
Rules that keep it alive
Thirty seconds, maximum. If an entry takes longer, it will not survive a bad week — and bad weeks are precisely when you most need the record to continue.
Record the dull days. The strong instinct is to write only when something is wrong, which produces a diary that reads far worse than the period it describes and hides the very thing you are looking for. An uneventful fortnight is data. It is what turns “I have been all over the place” into “I was steady for two weeks, then it slipped.”
Missing days is fine. A diary with gaps is enormously more useful than no diary. Skipping three days is not a failed attempt requiring a fresh start on Monday; just write today's.
Do not re-read it constantly. Especially not in the evening. The point is the shape over weeks, not tonight's verdict on yourself.
What it is not for
It is not a scoring system for your own performance, and it is not a diagnosis. A run of low numbers means the last fortnight was hard, which you already knew; it does not mean anything more specific than that, and reading it as a grade is a fast route to giving up.
It is also not something you have to show anyone. Some people keep it purely for the appointment. Some never show it to a soul and use it only to answer “is this actually getting worse, or does it just feel that way tonight?” Both are legitimate.
Where to keep it
Anywhere you will actually open, which is usually your phone. A note works perfectly well.
The one advantage of a purpose-built tool is that it does the remembering for you and can draw the line without you doing arithmetic. That is what Nagi's diary and weekly check-in are for, and the doctor report turns the whole stretch into one page you can hand over. But the habit is doing the work here, not the software. A paper notebook that gets used beats an app that does not.
The short version
Do not try to write your feelings. Write a number, your sleep, whether you went out, whether you spoke to anyone, and one flat sentence — plus the date of any medication change. Thirty seconds. Include the boring days. Miss some. In six weeks you will have the answer to a question you genuinely cannot answer any other way.
— Richard MacLean
Related: what your weekly score actually tells you and how to prepare for a mental health appointment.
Nagi is a mental health companion, not a medical device, and nothing here is medical advice. If you are struggling, please reach out to a professional or someone you trust.