Columbia subject headings:
Drug abuse--United States--Congresses.
Substance abuse--United States--Etiology--Congresses.
Substance abuse--United States--Psychology--Congresses.
Harvard subject headings:
Drug abuse--Etiology--Congresses.
Drug abuse--Psychological aspects--Congresses.
Princeton subject headings:
Drug abuse--Etiology--Congresses.
Drug abuse--Psychological aspects--Congresses.