General Antonyms:
* Distract: To draw attention away from something.
* Divert: To turn attention or resources away from something.
* Scatter: To spread out or disperse.
* Diffuse: To spread out or make less intense.
* Disperse: To scatter or spread out.
* Disregard: To pay no attention to.
* Ignore: To refuse to pay attention to.
* Neglect: To fail to pay attention to or take care of.
Antonyms in a Specific Context:
* Relax: The opposite of focusing and effort (e.g., "Instead of concentrating on work, I just want to relax").
* Daydream: To let your mind wander (e.g., "I tried to concentrate on the lecture, but I kept daydreaming").
* Procrastinate: To delay or postpone something (e.g., "I need to concentrate on finishing this project, but I keep procrastinating").
* Wander: To move aimlessly (e.g., "My mind wandered as I tried to concentrate on the book").
The best antonym will depend on the specific situation you are describing.