Can I claim my boyfriend as a dependent and claim the mortgage interest. I am not on the loan, if I have paid all bills since he lost his job a year ago?

Can you claim the BF ?   Yes if he files as a dependent (if he files at all) and lived with you ALL year and made less than $4400.  But before you determine if it is better for him to be a dependent or not figure your returns both ways and then make a decision.

As for the mortgage interest ... if you are not on the loan or on the deed then you cannot take the interest as a Sch A deduction even if you paid the bill.

Specifically, in order to deduct the mortgage interest (and/or the property taxes) you must have an ownership interest in the home (your name must be on the deed).