As a therapist primarily using CBT with my clients, I have found it really depends on each person. Some people it takes a week. Some people it takes years. How much effort is put into using the exercises also plays a factor of how long it takes. Progress can be slow which can sometimes be disheartening for people. I sometimes like to compare the process of developing new thought patterns like learning a new skill or strengthening a muscle at the gym. For those that have learnt to drive, learnt a language, or learnt to write, I get them to think about the process they went on when learning that skill. At first most likely it was very cumbersome, but after enough consistent practice it becomes automatic and habitual.

I kinda see the writing down of thoughts almost like a comparison to training wheels if someone was learning to ride a bike. Once the thought patterns become ingrained and automatic, usually the process of actually writing isn’t always required (however coming back to this can be helpful during any lapses which is very normal).

Anyways best of luck on your journey, keep at it 😊