Correct, every time after the FIRST draw. Second, third, fourth, etc all add Doubt to anyone attached to that Motive card. So, for example:
1. Draw a Motive against a Cultist, Cultist gains +1 Motive
2. Draw the same Motive against the Medium, Medium gains +1 Motive, BOTH gain +1 Doubt
And "KA" is a police acronym for "Known Associates." If you want to keep tabs on who is consorting with who.