Return to the Patient Health Questionnaire (PHQ-9 ) page
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									*Patient Health Questionnaire (PHQ-9)*
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Script Author: Katja Borchert, Ph.D. (katjab@millisecond.com) for Millisecond Software, LLC
Date: 04-02-2021
last updated: 04-02-2021 by K.Borchert (katjab@millisecond.com) for Millisecond Software LLC

Script Copyright © 04-02-2021 Millisecond Software

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BACKGROUND INFO 	
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This script implements a computerized version of the Patient Health Questionnaire (PHQ-9)
by Kroenke et al (2001).


Reference:
Kroenke, K., Spitzer, R. L., & Williams, J. B. W. (2001). The PHQ-9 - Validity of a brief 
depression severity measure. Journal of General Internal Medicine, 16, 606-613.

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OVERVIEW
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The scale consists of 9 4-point Likert scale items.
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DURATION 
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the default set-up of the script takes < 1 min to complete.

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DATA FILE INFORMATION 
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The default data stored in the data files are:

(1) Raw data file: 'phq_9.iqdat'

date, time:							date and time script was run with the current group/subjectnumber 
subject, group, session:	  		 with the current subject/groupnumber/session id
build:								the Inquisit build 

q*_response:						response given (in assigned values)
									Scale: q1-q9: 0 (Not at all) - 3 (Nearly every day)
									Scale: q10: 0 (Not difficult at all) - 3 (Extremely difficult)
									
q*_latency:							how much time (in ms) the participant spent on the surveypage with this particular 
									question (the last time this particular surveypage was visited)


(2) Summary data file: 'phq_9_summary.iqdat' (Inquisit Lab: one data file per participant)

inquisit.build:						the version/build of Inquisit
computer.platform:					the platform the script was run on (win/mac/ios/android)
script.startdate:					date script was run
script.starttime:					time script was started
script.subjectid:					assigned subject id number
script.groupid:						assigned group id number
script.elapsedtime:					time it took to run script (in ms); measured from onset to offset of script
script.completed:					0 = script was not completed (prematurely aborted); 
									1 = script was completed (all conditions run)
									
								
expressions.DepressedMoodOrAnhedonia:			1 = at least one answer for q1 (anhedonia) or q2 (depressed mood) 
												was a '2' or a '3 (>= more than half the days)
												0 = otherwise
												
values.DepressionSymptonsCounter:				counts the number of '2' or '3' responses (>= more than half the days)
												for q1-q8 as well as any response other than 0 for q9
												
												Major Depression if
												1. 'DepressedMoodOrAnhedonia' = 1 AND
												2.  DepressionSymptonsCounter >= 5
												
												Other Depression if
												1. 'DepressedMoodOrAnhedonia' = 1 AND
												2.  2 <= DepressionSymptonsCounter < 5
												
									
values.phq9_severityScore:							Total Score (adds up all valid response values from q1-q9; range: 0-27)
												1-4 Minimal depression
												5-9 Mild depression
												10-14 Moderate depression
												15-19 Moderately severe depression
												20-27 Severe depression 

individual responses: 
Scale: q1-q9: 0 (Not at all) - 3 (Nearly every day)
Scale: q10: 0 (Not difficult at all) - 3 (Extremely difficult)

radiobuttons.q1.response to 
expressions.q10 (*Note: q10 is only presented if participant has indicated any 
possible depression response (response > 0) for any of the nine questions. If 
all responses = 0, q10 is automatically scored with a 0)

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EDITABLE CODE 
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check below for (relatively) easily editable parameters, stimuli, instructions etc. 
Keep in mind that you can use this script as a template and therefore always "mess" with the entire code 
to further customize your experiment.

The parameters you can change are: