Array
(
    [1872] => Array
        (
            [parent_category_id] => 1872
            [parent_category] => Array
                (
                    [id] => 1872
                    [slug] => health-medical
                    [name] => Health and Medical
                )

            [subcategories] => Array
                (
                    [0] => Array
                        (
                            [name] => USMLE
                            [slug] => usmle
                            [id] => 1878
                        )

                )

        )

    [1744] => Array
        (
            [parent_category_id] => 1744
            [parent_category] => Array
                (
                    [id] => 1744
                    [slug] => science
                    [name] => Science
                )

            [subcategories] => Array
                (
                    [0] => Array
                        (
                            [name] => Biology
                            [slug] => biology
                            [id] => 1746
                        )

                    [1] => Array
                        (
                            [name] => Physiology
                            [slug] => physiology
                            [id] => 1750
                        )

                )

        )

)