A trauma bond is the powerful attachment that forms through repeated cycles of harm followed by relief or affection. The intermittent reward — cruelty, then warmth — conditions your nervous system like a slot machine, which is why leaving someone who hurt you can ache more than leaving someone who bored you. It's biology, not weakness.
Unpredictable reward is the strongest conditioning schedule there is. When the same person is both the source of fear and the source of comfort, your attachment system fuses the two. The highs aren't fake to your body — that's what makes the bond real and the leaving hard.