Make some up and post them!
Here are some I made up:
Yo mama's so ADHD that she couldn't lie still to get an abortion, so she had to have you.
Yo mama's so OCD she washes YOUR face with Javex. I was WONDERING how your complexion got that bad!
Yo mama's so bipolar she's low when she's suicidal when she's in your hemisphere and high when she's in the other one.
Yo mama's so ADHD she set a record for how many times a woman could get laid in one night, then she got so filled up with sperm that she had 16 babies at once. I only heard yesterday. So THAT's why you're ret*d... you were oxygen-deprived in the womb!
Yo mama's so psychotic she thought you were your sister and kissed you.
Yo mama's so psychotic she thought you were your sister and f****d you.
Yo mama's so depressed she went right down thru the earth, thru the core, up through the ground at the other end, and then she was happy again because she was far away from you!
Yo mama's so autistic she rocked back and forth while giving birth to you and bent you when you came out, and that's why you're shaped like a boomerang.