regressive

1. ADJ Regressive behaviour, activities, or processes involve a return to an earlier and less advanced stage of development. (行為、活動或過程)退化的; 倒退的[正式]

...some of the symptoms of regressive behaviours: thumb sucking, bed wetting, having problems sleeping. ...倒退行為的一些癥狀：吮姆指、尿床和睡眠不好。