A spouse can never be claimed as a dependent. But by filing as Married Filing Jointly (MFJ) you get the same benefits (and more) as having him as a dependent.
As a side note, SSDI (social security disability income) is potentially taxable, depending on how much other income the couple has. Filing as Married Filing Separately (MFS) is not a way to avoid that. Filing MFS makes SSDI taxable, at $0 income level
