update comment author id with wp_update_comment

I cannot change the user_ID with wp_update_comment. This example is working, the content is updated but not the user_ID. I tried also user_id.
Please help

function update_user_id( $comment_ID) {
	 $commentarr = array();
		  $commentarr['comment_ID'] = $comment_ID;
		  $commentarr['comment_content'] = 'Sample content';
		  $commentarr['user_ID'] = 1; 

		  wp_update_comment( $commentarr );  

	}

add_action( 'comment_post', 'update_user_id');