Photo Tip #56: Does Shutter Speed Affect Depth of Field?
The short answer is no it doesn't. However there some things that you must keep in mind when you are trying to to change your depth of field by changing your Aperture. First if you change your Aperture you are changing how much light you are exposing your sensor to. Which means you must either change your ISO or shutter speed or volume of light.
Conversely if you change your shutter speed you must also move the Aperture, ISO or volume of light.
Here is an example of 8 pictures where the Aperture remains the same but the shutter speed is changing. Pay close attention to the depth of field change between the first column and the second one. To compensate for the change of shutter speed, the volume of light is increased or decreased accordingly.
In this second set the ISO is moved to compensate for the change in shutter speed.