The reason why Coso has Depression is because of his creator Jackson, he thinks Jackson never cared about him and the rest of the animatronics, and used used him to hide drugs inside him without him knowing and had to replace his old counterpart to make people less suspicious about drugs inside the animatronics, and forced to attack people at night due to his programming even he doesn’t want to kill, and get him and the rest of the animatronics scrapped, but soon later on revived but no longer possessed along side with Cosa, after finding out Jackson used him, he get very pissed and depressed and it makes him feel like, he’s a worthless robot, a nobody, and he think he’s a hunk of junk, it made him wished he never exist. But Dondy comforts Coso by eases his pain, telling him he’s perfect everyone loves you, it told him it was his(Jackson’s)fault, but Coso was still depressed tho…..He just needed some time alone so he can calm down.