Oui93

Try "Yuuutsu no Asa" by Hidaka Shoko. It's not psychological but it has it's certain dark aspects through out the story. Dangerous lovehate relationship. It's long with 28 chapter(vol.6). Not complete though.
http://www.mangago.me/read-manga/yuuutsu_na_asa/

http://www.mangago.me/read-manga/the_inheritance_of_aroma/
http://www.mangago.me/read-manga/sakura_gari/
http://www.mangago.me/read-manga/gives/

Not long but totally recommend
http://www.mangago.me/read-manga/zion_no_koeda/
http://www.mangago.me/read-manga/butoukai_no_techou/

If you don't mind supernatural thrillers, Uki Ogasawara can craft some dark stories: http://www.mangago.me/read-manga/urakatana_kami_no_ki/
and http://www.mangago.me/read-manga/nightmare_fortress/ —although watch out because she can slip over into pure camp sometimes, with results that are more hilarious and WT

(old computer) WTF instead of dark and transgressive.

Then there's Ike Reibun with Bi no Isu: http://www.mangago.me/read-manga/bi_no_isu/ , and its side-story, http://www.mangago.me/read-manga/kobi_no_kyoujin/

Almost anything by Inariya Fusanosuke, http://www.mangago.me/read-manga/giglio/ or Mizukami Shin, http://www.mangago.me/read-manga/aigan_shounen/

Thanks! it looks interesting .

Thanks!

Thanks!

Thanks!