What is the total number of Pleasure(s), when Psychological Dependence is greater than 1.9, and when Drug is "Benzodiazepines"?
CREATE TABLE "addictive_potential" (
  "drug" text,
  "mean" real,
  "pleasure" real,
  "psychological_dependence" real,
  "physical_dependence" real
);
SELECT COUNT("pleasure") FROM "addictive_potential" WHERE "psychological_dependence">1.9 AND "drug"='benzodiazepines';