How does adding depreciation increases rental income?

I thought rental income = rents - expenses

Depreciation is considered an expense.  So wouldn't adding depreciation reduce your rental income according to the formula above?  A loan person says adding depreciation actually increases your rental income.  I don't understand.

So I forgot to add depreciation and proceeded to amend my taxes.

On schedule E (original taxes without depreciation added), line 24 "income" is $20,000.  On schedule E (amended taxes after adding back depreciation), line 24 "income" is now $100.  

However, on schedule E, line 25 "losses" went from -$17,000 to -$5000.  Adding depreciation reduced my loss.

But line 26 "total rental real estate income/loss" is the same number.


So it looks like my rental income reduced to $100 from $20,000 after adding back depreciation.  Why is it that loan officers say when you add back depreciation, your rental income increases?