I was only diagnosed a few months ago at 28 years old. I’ve been dealing with depression and anxiety since I was a teenager. Granted, most of the depression and anxiety was caused by my ADHD. I was on Concerta myself for a period of time but switched. Everyone will have their own medication which works for them. First of all, know that you’re NOT alone. This is a journey we’re all making together.
Journals can be considered a good thing, especially when reviewing your medication and its effectiveness. Use whatever method that you’re comfortable using. If you prefer paper, then go paper. If you prefer digital, go digital. The only upside of actually having a physical journal is the ability to take it with you to your psychologist or doctor. This allows you to easily reference dates and times on how you were feeling etc.
If you’re feeling down about something, then open up the journal and put down the reason you feel down. Maybe a thought came into your head, or maybe you saw something on the TV which got you anxious or down. Take notes of positive aspects as well, and not just negative ones. Think about why you’re feeling good today. Take notes on the effectiveness of the medication, timing the window in which it starts and ends. Or maybe how it’s not working as much as you want.
All these things can be useful. Taking a pro-active step is the right one to take. You’re already halfway there. Also, don’t get yourself down if the meds don’t work right away. ADHD is like a game of whack a mole when finding the right dose, medication type. When you find yours, you will know.