Table of Contents
Abstract
The Inventory of Depressive Symptomatology (IDS) and its abbreviated form, the Quick Inventory of Depressive Symptomatology (QIDS), are widely used psychometric evaluation tools designed to assess the severity of depression symptoms. Developed by A. John Rush and colleagues, these instruments capture the full range of criteria specified for a Major Depressive Episode (MDE) as defined by the DSM. Both the IDS (30 items) and QIDS (16 items) exist in two crucial formats: a Clinician Rating scale (IDS-C/QIDS-C) and a Self-report scale (IDS-SR/QIDS-SR). They are highly valued in clinical practice and research settings, particularly for monitoring treatment response and symptom change over time in patients diagnosed with Major Depressive Disorder (MDD).
Keywords
Inventory of Depressive Symptomatology, IDS, QIDS, Major Depressive Disorder, depression assessment, symptom severity, psychometrics, mood disorders, self-report scale, clinician rating.
Authors
A. John Rush, Donna E. Giles, Michael A. Schlesser, Carl L. Fulton, Jan Weissenburger, Cheryl Burns, Madhukar H. Trivedi, H. M. Ibrahim, T. J. Carmody, B. Arnow, D. N. Klein, J. C. Markowitz, P. T. Ninan, S. Kornstein, R. Manber, M. E. Thase, J. H. Kocsis, M. B. Keller.
Purpose
The primary purpose of the IDS and QIDS scales is to provide a comprehensive and quantitative measure of depressive symptom severity. Unlike some earlier scales, the IDS was specifically designed to capture every core symptom criterion of a Major Depressive Episode (MDE) according to standard diagnostic manuals. This comprehensive coverage ensures that subtle or atypical depressive presentations, such as those involving hypersomnia or increased appetite, are accurately documented.
In clinical trials and treatment settings, the instruments serve as reliable outcome measures. The brief version, QIDS, is particularly useful for rapid assessment and monitoring of treatment efficacy, allowing clinicians and researchers to track changes in symptom clusters—such as sleep, mood, and appetite—over short intervals, typically the past seven days.
Construct
The central psychological construct measured by the IDS and QIDS is the severity of Major Depressive Disorder (MDD) symptomology. The scales operationalize the nine symptom domains required for an MDD diagnosis (e.g., depressed mood, anhedonia, sleep disturbance, appetite/weight changes, psychomotor changes, fatigue, guilt/worthlessness, concentration difficulties, and suicidal ideation).
A key feature of these scales is their ability to address specific symptom presentations by requiring the respondent or clinician to select the most severe presentation from mutually exclusive options (e.g., choosing between decreased appetite/weight loss or increased appetite/weight gain). This methodology allows the scale to accurately score both typical and atypical depression presentations, providing a more nuanced and clinically relevant measure of the overall depressive burden.
Validity
The validity of the IDS and QIDS has been extensively established across numerous academic studies. The scales demonstrate strong content validity, as their items directly map onto the diagnostic criteria for Major Depressive Episode. Studies have also confirmed excellent concurrent validity, showing high correlations with other established depression measures, such as the Hamilton Rating Scale for Depression (HAM-D) and the Beck Depression Inventory (BDI).
Furthermore, the instruments exhibit robust discriminant validity, effectively distinguishing between different levels of depressive severity (e.g., mild, moderate, severe) and between depressed patients and healthy controls. The QIDS, specifically, was developed using rigorous psychometric evaluation techniques, confirming that its 16 items capture the variance of the full 30-item IDS, thus validating its use as a rapid, equivalent measure of depression severity.
Reliability
The IDS and QIDS demonstrate high internal consistency and inter-rater reliability, supporting their use as stable measurement tools. Studies confirm high test-retest reliability, indicating consistency of scores when administered multiple times under stable conditions. The inter-rater reliability is particularly strong for the clinician-rated versions (IDS-C and QIDS-C), suggesting that different clinicians arrive at consistent scores when evaluating the same patient.
The strong internal consistency (often measured by Cronbach’s alpha) across both the self-report and clinician-rated versions confirms that the items within the scale are measuring a single, cohesive underlying construct—the severity of depressive symptoms. This reliability is maintained even in diverse populations, including those with chronic Major Depressive Disorder.
Factor Analysis
Factor analyses conducted on the IDS and QIDS generally support a multi-faceted but highly correlated structure of depression. Early studies on the IDS suggested several underlying factors, including Mood/Cognition, Sleep Disturbance, and Appetite/Weight Change. These factors align well with the symptom clusters observed in clinical depression.
For the QIDS, factor analyses confirm that the 16 selected items adequately represent the core dimensions of depression captured by the longer IDS. While a single general factor of depression severity often accounts for a large portion of the variance, sub-factors related to physical/somatic symptoms (e.g., sleep, appetite) versus affective/cognitive symptoms (e.g., sadness, self-view) are consistently observed, providing empirical support for the scale’s structure.
Instrument
Test Type: Symptom Severity Rating Scale (IDS) and Quick Severity Rating Scale (QIDS)
Format: Likert-type scale, typically scored 0 to 3 or 0 to 4 depending on the specific item and version. Both Clinician-Rated (IDS-C, QIDS-C) and Self-Report (IDS-SR, QIDS-SR) formats are available.
Language Available: English (original), with numerous translations available globally, as indicated by the IDS/QIDS official website.
Population Group: Clinical and non-clinical populations experiencing symptoms of depression or mood disorders.
Age Group: Typically utilized with adults (18+) in clinical settings, though adaptations or specific versions may exist for adolescents.
Population Details: Used extensively in psychiatric research, including large-scale clinical trials such as STAR*D (Sequenced Treatment Alternatives to Relieve Depression), demonstrating efficacy across diverse public sector patients with mood disorders.
Test Methodology: Respondents (or clinicians) rate the severity of symptoms experienced over the past seven days. The QIDS-SR uses the highest score from mutually exclusive pairs (e.g., insomnia vs. hypersomnia) across 16 core items to generate a total score ranging from 0 to 27.
Keywords
Depressive symptoms, Major Depressive Episode, IDS-SR, QIDS-C, psychomotor agitation, hypersomnia, anhedonia, mood fluctuation, clinical trial outcome measure.
Authors
Author ORCID Identifier: Not consistently provided for all authors in the public domain; check institutional profiles for A. John Rush and Madhukar H. Trivedi.
Affiliation Email addresses: Contact information is typically managed through the institutional affiliations of the authors (e.g., UT Southwestern Medical Center, as per original publications).
Correspondence Address: Refer to the primary publications (Rush et al., 1986; Trivedi et al., 2004) for institutional addresses at the time of publication.
Permissions & Fee and Test Year
The original Inventory of Depressive Symptomatology (IDS) was introduced in 1986 (Rush et al., 1986). The Quick Inventory of Depressive Symptomatology (QIDS) was developed and published in 2003 (Rush et al., 2003) to provide a shorter, equally valid measure. The scales are generally available for non-commercial research and clinical use, often requiring registration through the official IDS-QIDS website to ensure proper usage and scoring guidelines are followed. The instruments are considered highly accessible within the psychiatric community.
Reference’s
- Rush. A. John, Giles. Donna E., Schlesser. Michael A., Fulton. Carl L., Weissenburger. Jan, Burns Cheryl. 1986. The inventory for depressive symptomatology (IDS): Preliminary findings. Psychiatry Research, 18(1); 65–87.
- Rush AJ, Trivedi MH, Ibrahim HM, Carmody TJ, Arnow B, Klein DN, Markowitz JC, Ninan PT, Kornstein S, Manber R, Thase ME, Kocsis JH, Keller MB: The 16-Item Quick Inventory of Depressive Symptomatology (QIDS), clinician rating (QIDS-C), and self-report (QIDSSR): a psychometric evaluation in patients with chronic major depression. Biol Psychiatry 2003; 54:573–83.
- Trivedi MH, Rush AJ, Ibrahim HM, Carmody TJ, Biggs MM, Suppes T, CrismonML, Shores- Wilson K, Toprac MG, Dennehy EB, Witte B, Kashner TM: The inventory of depressive symptomatology, clinician rating (IDS-C) and self-report (IDS-SR), and the quick inventory of depressive symptomatology, clinician rating (QIDS-C) and self-report (QIDS-SR) in public sector patients with mood disorders: a psychometric evaluation. Psychol Med 2004; 34:73–82.
The official instrument and related resources are available online at: http://www.ids-qids.org/. The original PDF for the IDS-SR English (South Africa version) can be downloaded here: http://www.ids-qids.org/translations/english/IDS-SREnglish-SouthAfrica.pdf.
Items of the Inventory of Depressive Symptomatology (IDS or QIDS)
IMPORTANT: The following scale items must be preserved in their original language and must not be changed in any way.
0. I never take longer than 30 min to fall asleep.1. I take at least 30 min to fall asleep‚ less than half the time.2. These feeling states spontaneously reported verbally3. I take at least 30 min to fall asleep‚ more than half the time.4. I take more than 60 min to fall asleep‚ more than half the time.
0. I do not wake up at night.1. I have a restless‚ light sleep with a few brief awakenings each night.2. I wake up at least once a night‚ but I go back to sleep easily.3. I awaken more than once a night and stay awake for 20 min or more‚ more than half the time.
0. Most of the time‚ I awaken no more than 30 min before I need to get up.1. More than half the time‚ I awaken more than 30 min before I need to get up.2. I almost always awaken at least 1 hour or so before I need to‚ but I go back to sleep eventually.3. I awaken at least 1 hour before I need to‚ and can’t go back to sleep.
0. I sleep no longer than 7–8 hours/night‚ without napping during the day.1. I sleep no longer than 10 hours in a 24-hour period including naps.2. I sleep no longer than 12 hours in a 24-hour period including naps.3. I sleep longer than 12 hours in a 24-hour period including naps.
0. I do not feel sad.1. I feel sad less than half the time.2. I feel sad more than half the time.3. I feel sad nearly all of the time.
0 – There is no change in my usual appetite.1 – I eat somewhat less often or lesser amounts of food than usual.2 – I eat much less than usual and only with personal effort.3 – I rarely eat within a 24-hour period‚ and only with extreme personal effort or when others persuade me to eat.
0 – There is no change from my usual appetite.1 – I feel a need to eat more frequently than usual.2 – I regularly eat more often and/or greater amounts of food than usual.3 – I feel driven to overeat both at mealtime and between meals.
0 – I have not had a change in my weight.1 – I feel as if I’ve had a slight weight loss.2 – I have lost 2 pounds or more.3 – I have lost 5 pounds or more.
0 – I have not had a change in my weight.1 – I feel as if I’ve had a slight weight gain.2 – I have gained 2 pounds or more.3 – I have gained 5 pounds or more.
0 – There is no change in my usual capacity to concentrate or make decisions.1 – I occasionally feel indecisive or find that my attention wanders.2 – Most of the time‚ I struggle to focus my attention or to make decisions.3 – I cannot concentrate well enough to read or cannot make even minor decisions.
0 – I see myself as equally worthwhile and deserving as other people.1 – I am more self-blaming than usual.2 – I largely believe that I cause problems for others.3 – I think almost constantly about major and minor defects in myself.
0 – I do not think of suicide or death.1 – I feel that life is empty or wonder if it’s worth living.2 – I think of suicide or death several times a week for several minutes.3 – I think of suicide or death several times a day in some detail‚ or I have made specific plans for suicide or have actually tried to take my life.
0 – There is no change from usual in how interested I am in other people or activities.1 – I notice that I am less interested in people or activities.2 – I find I have interest in only one or two of my formerly pursued activities.3 – I have virtually no interest in formerly pursued activities.
0 – There is no change in my usual level of energy.1 – I get tired more easily than usual.2 – I have to make a big effort to start or finish my usual daily activities (for example‚ shopping‚ homework‚ cooking or going to work).3 – I really cannot carry out most of my usual daily activities because I just don’t have the energy.
0 – I think‚ speak‚ and move at my usual rate of speed.1 – I find that my thinking is slowed down or my voice sounds dull or flat.2 – It takes me several seconds to respond to most questions and I’m sure my thinking is slowed.3 – I am often unable to respond to questions without extreme effort.
0 – I do not feel restless.1 – I’m often fidgety‚ wring my hands‚ or need to shift how I am sitting.2 – I have impulses to move about and am quite restless.3 – At times‚ I am unable to stay seated and need to pace around.
0. I never took more than 30 minutes to fall asleep.1. I took at least 30 minutes to fall asleep‚ less than half the time (3 days or less out of the past 7 days).2. I took at least 30 minutes to fall asleep‚ more than half the time (4 days or more out of the past 7 days).3. I took more than 60 minutes to fall asleep‚ more than half the time (4 days or more out of the past 7 days).
0. I did not wake up at night.1. I had a restless‚ light sleep‚ waking up briefly a few times each night.2. I woke up at least once a night‚ but I went back to sleep easily.3. I woke up more than once a night and stayed awake for 20 minutes or more‚ more than half the time (4 days or more out of the past 7 days).
0. Most of the time‚ I woke up no more than 30 minutes before I needed to get up.1. More than half the time (4 days or more out of the past 7 days)‚ I woke up more than 30 minutes before I needed to get up.2. I almost always woke up at least one hour or so before I needed to get up‚ but I went back to sleep eventually.3. I woke up at least one hour before I needed to get up‚ and could not go back to sleep.
0. I slept no more than 7-8 hours/night‚ without napping during the day.1. I slept no more than 10 hours in a 24-hour period including naps.2. I slept no more than 12 hours in a 24-hour period including naps.3. I slept more than 12 hours in a 24-hour period including naps.
0. I did not feel sad.1. I felt sad less than half the time (3 days or less out of the past 7 days).2. I felt sad more than half the time (4 days or more out of the past 7 days).3. I felt sad nearly all the time.
0. I did not feel irritable.1. I felt irritable less than half the time (3 days or less out of the past 7 days).2. I felt irritable more than half the time (4 days or more out of the past 7 days).3. I felt extremely irritable nearly all the time.
0. I did not feel anxious or tense.1. I felt anxious (tense) less than half the time (3 days or less out of the past 7 days).2. I felt anxious (tense) more than half the time (4 days or more out of the past 7 days).3. I felt extremely anxious (tense) nearly all the time.
0. My mood brightened to a normal level which lasted for several hours when good circumstances occurred.1. My mood brightened but I did not feel like my normal self when good circumstances occurred.2. My mood brightened only somewhat to a rather limited range of desired circumstances.3. My mood did not brighten at all‚ even when very good or desired circumstances occurred in my life.
0. There was no regular relationship between my mood and the time of day.1. My mood was often related to the time of day because of environmental circumstances (e.g.‚ being alone‚ working).2. In general‚ my mood was more related to the time of day than to environmental circumstances.3. My mood was clearly and predictably better or worse at a particular time each day.
0. The mood (internal feelings) that I experienced was very much a normal mood.1. My mood was sad‚ but this sadness was pretty much like the sad mood I would feel if someone close to me had died or left.2. My mood was sad‚ but this sadness was a little bit different from the sadness I would feel if someone close to me had died or left.3. My mood was sad‚ but this sadness was very different from the type of sadness associated with grief or loss.
0. There was no change in my usual appetite.1. I ate somewhat less often or lesser amounts of food than usual.2. I ate much less than usual and only with personal effort.3. I rarely ate within a 24-hour period‚ and only with extreme personal effort or when others persuaded me to eat.
0. There was no change from my usual appetite.1. I felt a need to eat more frequently than usual.2. I regularly ate more often and/or larger amounts of food than usual.3. I felt driven to overeat both at mealtime and between meals.
0. I did not have a change in my weight.1. I feel as if I’ve had a slight weight loss.2. I lost 1 kilogram or more.3. I lost 2 kilograms or more.
0. I did not have a change in my weight.1. I feel as if I’ve had a slight weight gain.2. I gained 1 kilogram or more.3. I gained 2 kilograms or more.
0. There was no change in my usual capacity to concentrate or make decisions.1. I occasionally felt indecisive or found that my attention wandered.2. Most of the time‚ I struggled to focus my attention or to make decisions.3. I could not concentrate well enough to read or could not make even minor decisions.
0. I saw myself as equally worthwhile and deserving as other people.1. I was more self-blaming than usual.2. I largely believed that I caused problems for others.3. I thought almost constantly about major and minor defects in myself.
0. I had an optimistic view of my future.1. I was occasionally pessimistic about my future‚ but for the most part I believed things would get better.2. I was pretty certain that my immediate future (1-2 months) did not hold much promise of good things for me.3. I saw no hope of anything good happening to me at any time in the future.
0. I did not think of suicide or death.1. I felt that life was empty or wondered if it was worth living.2. I thought of suicide or death several times a week for several minutes.3. I thought of suicide or death several times a day in some detail‚ or I made specific plans for suicide or actually tried to take my life.
0. There was no change from usual in how interested I was in other people or activities.1. I noticed that I was less interested in people or activities.2. I found I had interest in only one or two of my formerly pursued activities.3. I had virtually no interest in formerly pursued activities.
0. There was no change in my usual level of energy.1. I got tired more easily than usual.2. I had to make a big effort to start or finish my usual daily activities (for example‚ shopping‚ homework‚ cooking or going to work).3. I really could not carry out most of my usual daily activities because I just did not have the energy.
0. I enjoyed pleasurable activities just as much as usual.1. I did not feel my usual sense of enjoyment from pleasurable activities.2. I rarely got a feeling of pleasure from any activity.3. I was unable to get any pleasure or enjoyment from anything.
0. I was just as interested in sex as usual.1. My interest in sex was somewhat less than usual or I did not get the same pleasure from sex as I used to.2. I had little desire for or rarely derived pleasure from sex.3. I had absolutely no interest in or derived no pleasure from sex.
0. I thought‚ spoke‚ and moved at my usual rate of speed.1. I found that my thinking was more sluggish than usual or my voice sounded dull or flat.2. It took me several seconds to respond to most questions and I am sure my thinking was more sluggish than usual.3. I was often unable to respond to questions without extreme effort.
0. I did not feel restless.1. I was often fidgety‚ wrung my hands‚ or needed to shift around when I was sitting.2. I had impulses to move about and was quite restless.3. At times‚ I was unable to stay seated and needed to pace around.
0. I did not have any feeling of heaviness in my arms or legs and did not have any aches or pains.1. Sometimes I had headaches or pains in my stomach‚ back or joints but these pains were only present some of the time and they did not stop me from doing what I needed to do.2. I had these sorts of pains most of the time.3. These pains were so bad they forced me to stop what I was doing.
0. I did not have any of these symptoms: heart pounding fast‚ blurred vision‚ sweating‚ hot and cold flashes‚ chest pain‚ palpitations‚ ringing in my ears‚ or shaking.1. I had some of these symptoms but they were mild and were present only sometimes.2. I had several of these symptoms and they bothered me quite a bit.3. I had several of these symptoms and when they occurred I had to stop doing whatever I was doing.
0. I had no panic spells or specific fears (phobia) (such as of animals or heights).1. I had mild panic episodes or fears that did not usually change my behaviour or stop me from functioning.2. I had significant panic episodes or fears that forced me to change my behaviour but did not stop me from functioning.3. At least once a week‚ I had panic episodes or severe fears that stopped me from carrying on with my daily activities.
0. There was no change in my usual bowel habits.1. I had intermittent constipation or diarrhea which was mild.2. I had diarrhoea or constipation most of the time but it did not interfere with my day-to-day functioning.3. I had constipation or diarrhoea for which I took medicine or which interfered with my day-to-day activities.
0. I did not easily feel rejected‚ slighted‚ criticized or hurt by others at all.1. I occasionally felt rejected‚ slighted‚ criticised or hurt by others.2. I often felt rejected‚ slighted‚ criticised or hurt by others‚ but these feelings had only slight effects on my relationships or work.3. I often felt rejected‚ slighted‚ criticised or hurt by others and these feelings impaired my relationships and work.
0. I did not experience the sensation of feeling physically exhausted and without physical energy.1. I occasionally experienced periods of feeling physically exhausted and without physical energy‚ but without a negative effect on work‚ school‚ or activity level.2. I felt physically exhausted (without physical energy) more than half the time (4 days or more out of the past 7 days).3. I felt physically exhausted (without physical energy) most of the time‚ several hours per day‚ several days per week.