Instrument	Date of introduction	Number of items	Time frame of questions	Score range	Usual cutoff point*	Literacy level†	Administration time (minutes)
After publication of DSM-III-R (1987)
PHQ-213,14	2003	2	Past two weeks	0 to 6	3	Average	< 1
PHQ-915	1999	9	Past two weeks	0 to 27	10	Average	< 3
Medical outcomes study–Depression test16	1995	8	Past week	0 to 1	0.06	Average	< 2
Before publication of DSM-III-R
Beck Depression inventory17,18	1961	21	today	0 to 63	10 (mild) 20 (moderate) 30 (severe)	Easy	2 to 5
Center for epidemiologic study–Depression scale19	1977	20	Past week	0 to 60	16	Easy	2 to 5
General Health Questionnaire20,21	1972	28	Past few weeks	0 to 28	4	Easy	5 to 10
Zung self-assessment Depression scale22	1983	20	recently	25 to 100	50 (mild) 60 (moderate) 70 (severe)	Easy	2 to 5