Agrupar noticias por meses usando TIMESTAMP

[Takitei]

He tratado de aplicar la cláusula a mi consulta, pero no funciona, me da error de SINTAX. He probado lo siguiente:

SELECT DISTINCT *, DATE_FORMAT(postedon,'%M %Y') AS dateGroup FROM news ORDER by dateGroup

SELECT *, DISTINCT DATE_FORMAT(postedon,'%M %Y') AS dateGroup FROM news ORDER by dateGroup

SELECT *, DISTINCT(DATE_FORMAT(postedon,'%M %Y')) AS dateGroup FROM news ORDER by dateGroup

SELECT *, DISTINCT(DATE_FORMAT(postedon,'%M %Y') AS dateGroup) FROM news ORDER by dateGroup

SELECT *, DATE_FORMAT(postedon,'%M %Y') AS DISCTINCT dateGroup FROM news ORDER by dateGroup

SELECT *, DATE_FORMAT(postedon,'%M %Y') AS DISTINCT(dateGroup) FROM news ORDER by dateGroup

SELECT *, DATE_FORMAT(postedon,'%M %Y') AS dateGroup DISTINCT dateGroup FROM news ORDER by dateGroup

Ninguna funciona. ¿Qué estoy haciendo mal?