Can a person that doesn't have adhd take adhd medicine to focus?

Not recommended: People who do not have adhd are not recommended to take stimulant medications as these medications are addictive in non adhd people.

Not recommend: That would not be the recommendation . If you don't need a medication don't take it. You risk an unnecessary side effect.

Not indicated: Most of these meds are schedule 2 controlled drugs. They are closely monitored by the feds. A doc that prescribes them without a valid diagnosis backed up with a chart & testing can loose their license &/or ability to prescribe these drugs. Possession without a prescription equates to possessing meth. While they might help you focus, they do come with risks other than side effects.