Psionics and Magic: How do they interact?
Is a question I do not answer in Paranormal Power, for four reasons.
Firstly, Antimagic Fields exist not only to disable spellcasting, but also magical equipment. There is no psionic equipment in this book. Mostly because I find that magical items are a core piece of D&D/Level Up/Fantasy gaming's specific narrative fantasy. While Psionic Equipment really isn't a specific "Thing" with narrative weight to it. And to some degree I wanted to avoid 3e's "Everything is Crystals" psionic items.
Secondly, they do so largely for the benefit of players rather than NPCs since players have greater agency to prepare such spells. It's a specific function of an aspect of magic to shut itself down to weaken a magical foe. Personally I've never felt it made sense to apply it to psionics for that reason. And resulting from that: There is no anti-psionic power for players to wield against NPCs.
Thirdly, The Psionics presented in this book are slightly weaker, for combat purposes, than spellcasting. Using the split basic augment, for example, allows an Esper to hit more targets than normal, but any psi dice put toward splitting a power to make it hit more people is a die that could have increased the damage of the power, outright. And with a maximum of 9 psi dice total, even their maximum power on a single target is about 10d8.
Finally, it's going to be a setting dependent decision in most cases. In a gonzo high fantasy setting like the Forgotten Realms where all power is tied into Mystra's Weave, it makes sense for psionics to be suppressed if psionics is an interaction with the weave. While in Dark Sun, the aggressive and often feral nature of psionics being capable of bypassing defiling magic gives espers a chance to overthrow the Sorcerer Kings.
Personally, I don't feel that Psionics need to be suppressed by an antimagic field for these reasons. But I ultimately did not make that choice for the system, instead leaving it up to a given Narrator or Dungeon Master, based on their own personal preference and setting's rules of psionic and magical interaction.