How many {measured by} are for {mental depression} ?
What measurements are taken for the disease depression?
What are the measurements for the mental depression disease ?
SELECT ( COUNT ( ?u ) AS ?n ) { resource:mental_depression property:measurement_scale ?u }
SELECT (COUNT(?obj) AS ?objs ) {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q4340209> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P1880> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> ?obj .
} 

SELECT (COUNT(?obj) AS ?value ) { wd:Q4340209 wdt:P1880 ?obj }
10