wspencer on "wp_update_comment not working"

I've created a custom comment editor and for some reason, wp_update_comment is not working. It returns 1, which means it should have been successful but it's not actually updating anything. Listed below is my update code. It's important to note that I've double checked that the proper data is being added to $commentarr from the form POST.

$commentarr = array();
$commentarr['comment_ID'] = $comment_ID;
$commentarr['comment_content'] = $commentContent;
$update_success = wp_update_comment($commentarr);

    if ($update_success == 1) {
        $comment = get_comment($comment_ID);
        $article_link = get_permalink($comment->comment_post_ID);
        wp_redirect( $article_link );
    }

    else {
        $commentError = 'Something went wrong while updating your comment.';
        $hasError = true;
    }