Tax refunds are determined by the relationship between the taxes you owe on your income versus the total of your withheld taxes and any refundable tax credits. There has never been such a thing as a refund based solely on claiming a dependent.

If you are referring to a specific tax credit, such as the Child Tax Credit or the Earned Income Tax Credit, you would have to be certain that you met every requirement for that credit. Please see IRS Pub. 17 Your Federal Income Tax, Chapter 31 et seq., for details about qualifying for the various tax credits.

If you are referring to the Personal Exemption, which was an amount subtracted from your income for every person included in your tax return, those exemptions were eliminated by the Tax Cuts and Jobs Act of 2017.