It was the drugs, not her mental health, that put Buffy in a catatonic state. Normally the catatonia was something that health professionals tried to cure or limit with medicine, not recreate. But it was the only way they could keep the Slayer contained with any certainty. Even without her powers, the Slayer while not being smart was certainly prone to clever. Arkahm couldn’t risk it.
So she sat in the chair perfectly still. And two hours later a nurse came to give the Slayer another injection.
The next two hours went the same, as they always did, except with four minutes left Buffy’s eyes fluttered softly. After how many days of being pumped with chemicals the Slayer was either developing a resistance or learning how to fight it.
Three minutes now. It wouldn’t be enough time to move before the staff came in again. Buffy hadn't moved yet, but the vacant look in her eye had been replaced with awareness. She was trying.