Hayden Panettiere Getting Treated for Postpartum Depression

Hayden Panettiere has checked herself into a treatment center for postpartum depression ... TMZ has confirmed.

The "Nashville" star, who gave birth to daughter Kaya, back in December of 2014, says, "When [you're told] about postpartum depression you think it's 'I feel negative feelings toward my child, I want to injure or hurt my child,' I've never, ever had those feelings."

Hayden added, "Women need to know that they're not alone, and that it does heal."

It's ironic ... the main storyline on "Nashville" right now centers around Hayden's character going off the rails as a result of postpartum depression.