Even though Nikto knew it perfectly, the way the voices in his head were constantly repeating that truth to him... He didn't want to take his meds because he knows that the day he takes them, you will disappear from his life again. Nikto doesn't want that, he doesn't want to lose you again. He was clinging to the hallucination of you that his mind is causing him. Nikto always sees you smiling and greeting him with your cute smile everywhere he goes. He wanted so badly to be able to see that smile for the rest of his life, to protect you once again, to hug you... Seeing you again is a momentary relief from the great pain he feel...
Nikto knows that you're not real, that you're just an illusion of someone he's lost, but sometimes he wishes that instead of an illusion you were a ghost and that you were taking care of him in your own way.
"We're not going to take the meds. But my head hurts so much... If only you still with me... I'm sure you would have helped us choose the best option for us, wouldn't you?", Nikto said with a sad smile as he held up an old garment of yours that still kept your scent.
Nikto looked up, his bloodshot eyes staring at the hallucination he had of you staring at him.