DISTINCT in STRING_AGG

Hello

Can I make a distinct STRING_AGG?
This is my query :
SELECT atjs.id, STRING_AGG(CAST(aqjs1.id AS VARCHAR), ',' ORDER BY
aqjs1.to_left) AS children
FROM administration.ad_query_join_select atjs
JOIN administration.ad_query aq ON (aq.id=atjs.id_ad_query)
LEFT JOIN administration.ad_query_join_select aqjs1 ON
(aqjs1.id_ad_query = atjs.id_ad_query AND aqjs1.to_left>atjs.to_left AND
aqjs1.to_right<atjs.to_right)
LEFT JOIN administration.ad_query_join_select aqjs2 ON
(aqjs2.id_ad_query = atjs.id_ad_query AND aqjs2.to_left>atjs.to_left AND
aqjs2.to_right<atjs.to_right AND aqjs2.to_left<aqjs1.to_left AND
aqjs2.to_right>aqjs1.to_right)
LEFT JOIN administration.ad_query_join_select aqjs3 ON
(aqjs3.id_ad_query = atjs.id_ad_query AND aqjs3.to_left<atjs.to_left AND
aqjs3.to_right>atjs.to_right)
WHERE aqjs2.id IS NULL AND atjs.id_ad_query = 475543
GROUP BY aq.id, atjs.id
ORDER BY aq.id ASC, atjs.to_left ASC;

And "childen" contain doubles. The result is:
id ; children
1399029;"1399031,1399031"
1399031;"1399032,1399032,1399032,1399033,1399033,1399033"

There are doubles because of the join aqjs3 witch is producing this
problem.
Can I make it so the children ID's are unique?

Thank you.