Mood journal: how to track your mood and learn from it

A mood journal is a record of how you felt, day after day. The idea is simple and the payoff is slow: a single entry teaches you nothing, but a month of them shows things nobody notices while living day to day.

What to write in each entry

• How you are, on a short scale, from light to heavy. Five levels are enough.
• A name for what you're feeling, if you can: tired, irritated, calm, anxious, excited. If you can't, that's fine.
• What was going on: where you were, who with, what you'd just done.
• A sentence or two about the day. That's what makes the entry make sense three months from now.

Context is the part most people skip and the part they miss most later. “Bad day” explains nothing. “Bad day, slept badly and the meeting ran two hours late” explains almost everything.

When to log it

Once a day works for almost everyone, ideally around the same time. In the evening you can look at the whole day, just keep in mind that one bad hour at the end tends to colour the rest. If the morning was good and the night wasn't, write both.

How to read it after a few weeks

Don't re-read every day. After three or four weeks, look at all of it at once and look for repetition: a weekday that tends to be heavy, a person who shows up on the light days, a topic that keeps appearing right before a hard week.

One caution: showing up together doesn't mean causing. If every Monday is heavy, it could be Monday, it could be the Sunday before it, it could be chance. The journal raises the question, it doesn't answer it on its own.

What a mood journal isn't

It isn't a diagnosis. Tracking your mood helps you observe yourself and talk more clearly with a professional, but it doesn't tell you what you have. If what shows up in your entries worries you, that's something to bring to a mental health professional.

Paper, spreadsheet or app

Any of them works, as long as you use it. Paper is simple and asks for nothing. In an app, each day's mood turns into a coloured calendar with no effort, and seeing the whole month at once gets easier.

The hard part is cross-referencing everything: which topic shows up on the heavy days, who's around on the light ones. That kind of reading is worth leaving to a machine, as long as the record stays yours.