A therapy session lasts about an hour, while the week around it lasts another 167. Most of what you want to talk about happens in those other hours, such as the evening your mood dropped for no clear reason, the morning you felt fine and could not say why, or the conversation you replayed all night. By the time you are back in the room, much of that detail has faded.
That gap is one reason therapists so often ask people to keep notes. The NHS describes cognitive behavioural therapy as something you practise between sessions, and says you may be asked to record your progress in a worksheet or diary. NHS Talking Therapies makes the same point about practising what you have learned between appointments.
Yet “keep a diary” is vague advice, rather like the gentle habit of writing a few lines to close the day without knowing what to put in them. Here is what tends to be worth writing down, and what usually is not.
Mood as a number and a word
A quick rating from 0 to 10 takes five seconds and builds into something useful over a few weeks. Add one word beside it, such as flat, wired, tense, or calm, so the number shows the pattern and the word tells you what kind of low or high it was.
What happened just before
When your mood shifts, note what came immediately before it, whether a message, a meeting, a skipped meal, a bad night, or a particular place. You are not trying to explain it yet; you are collecting raw material that your therapist can help you make sense of.
The thought that showed up
If a sentence keeps running through your head, such as “I always mess this up” or “they think I’m useless”, write it down word for word. Exact wording matters, because it is much easier to look at a thought together when it appears on the page in the form it actually took.
What you did next
Did you go for a walk, cancel plans, scroll for two hours, or call a friend? Writing down what you did, without judging it, shows which reactions help you and which keep you stuck.
Sleep, food, and medication
These are easy to skip and often explain more than anything else. A short night, a missed dose, or a day without a proper meal can change how the following day feels, which can matter when you are trying to tell burnout from depression. If you take medication, noting when you took it and anything unusual you noticed gives your prescriber something concrete to work with.
One thing that went all right
People in a low patch tend to remember the bad days in detail and the decent ones not at all. One line a day about something that went fine, however small, helps balance the record.
What not to worry about
You do not need to write well, and you do not need to write every day. Gaps are information too, and a blank week often says something worth discussing. This is not a test you can fail; the point is to bring a clearer picture into the room, not a perfect one.
Bringing it to your session
Before your appointment, look back over the week and pick two or three things that stand out, such as a pattern, a day you want to understand, or a thought that kept returning. Starting there is often easier than trying to recall the whole week on the spot.
Some people prefer a paper notebook, while others use an app because a rating and a note take seconds on a phone and the patterns appear by themselves. Either way, what matters is that the record is yours, quick to keep, and comes with you to the next appointment.
Therapy works on what you bring to it. A few lines a day mean you bring more of your week, and less of it is lost to memory.
