As they said, anything by Harada. But here's some more...be warned, some have really sad endings, but I tried to not include the graphically violent or gross ones:
http://www.mangago.zone/read-manga/mud/
http://www.mangago.zone/read-manga/nanadome_no_gomenne/
http://www.mangago.zone/read-manga/my_god/
http://www.mangago.zone/read-manga/s_no_kaikoroku/
http://www.mangago.zone/read-manga/samenai_yume/
http://www.mangago.zone/read-manga/abnormal_kei_joshi/
http://www.mangago.zone/read-manga/to_the_sea/
http://www.mangago.zone/read-manga/zankoku_na_kami_ga_shihai_suru/
http://www.mangago.zone/read-manga/torikago_syndrome/
http://www.mangago.zone/read-manga/tenshi_no_uta_nishida_higashi/
http://www.mangago.zone/read-manga/kasane/
http://www.mangago.zone/read-manga/red_theatre/
http://www.mangago.zone/read-manga/shinkai_no_venus/
http://www.mangago.zone/read-manga/sachiiro_no_one_room/
http://www.mangago.zone/read-manga/dogeza_shite_kudasai/
http://www.mangago.zone/read-manga/suki_ni_shitaiyo/
http://www.mangago.zone/read-manga/kyuuso_neko_o_kurau/
http://www.mangago.zone/read-manga/ibitsu_na_boku_wo_douka_aishite/
http://www.mangago.zone/read-manga/chou_to_kumo_no_su/
What are some good psychological mindfucky stories?? I’ve read a few but I want to read more of that kind of stuff :)