Beck Depression Inventory

Abstract

The Beck Depression Inventory (BDI), and its principal modern revision, the Beck Depression Inventory-II (BDI-II), is among the most widely utilized self-report psychometric instruments designed to quantify the severity of depressive symptomatology in adults and adolescents aged 13 years and older. Developed initially by Aaron T. Beck in 1961 and revised in 1996 in collaboration with Robert A. Steer and Gregory K. Brown, the 21-item questionnaire aligns directly with the diagnostic criteria for major depressive disorder specified in the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV and DSM-5). The inventory assesses emotional, cognitive, somatic, and vegetative manifestations of depression, including persistent sadness, pessimism, perceived past failure, loss of pleasure (anhedonia), guilty feelings, punishment feelings, self-dislike, self-criticalness, suicidal ideation, crying proneness, agitation, loss of interest, indecisiveness, perceived worthlessness, loss of energy, changes in sleeping patterns, irritability, changes in appetite, concentration difficulties, tiredness or fatigue, and loss of libido. Each item comprises four evaluative statements scaled from 0 (absence of symptom) to 3 (severe symptom manifestation), yielding a total cumulative score ranging from 0 to 63. Across hundreds of independent clinical and non-clinical psychometric evaluations worldwide, the BDI-II exhibits exceptional internal consistency (Cronbach’s α typically ranging between .91 and .93 in psychiatric cohorts and .86 to .91 in collegiate/community samples) and robust test-retest stability (r = .93 across a one-week interval). Factor analytic studies predominantly support an overarching general depression dimension alongside correlated two-factor (Cognitive-Affective and Somatic-Vegetative) or bifactor structural models. The instrument maintains widespread diagnostic, therapeutic, and epidemiological utility, functioning as a primary benchmark for monitoring treatment response and symptom progression in empirical research and clinical practice.

Keywords

Beck Depression Inventory, BDI-II, major depressive disorder, psychometrics, self-report assessment, cognitive triad, depressive severity, anhedonia, internal consistency, factor analysis, psychiatric evaluation, clinical outcome measure

Authors

The original Beck Depression Inventory was authored by Aaron Temkin Beck, M.D. (1921–2021), Professor Emeritus of Psychiatry at the University of Pennsylvania Perelman School of Medicine and widely regarded as the father of Cognitive Therapy and Cognitive Behavioral Therapy (CBT). Working alongside Beck on the 1996 comprehensive revision (BDI-II) were Robert A. Steer, Ed.D., Professor of Psychiatry at the University of Medicine and Dentistry of New Jersey (UMDNJ), and Gregory K. Brown, Ph.D., Research Associate Professor of Clinical Psychology in Psychiatry at the University of Pennsylvania.

The official Dutch standardization and validation of the BDI-II was conducted by A. J. Willem van der Does, Ph.D. (2002), Professor of Clinical Psychology at Leiden University and Leiden Institute for Brain and Cognition (LIBC), Netherlands, in collaboration with Pearson Assessment and Information B.V. Primary developmental correspondence historically originated through the Center for Cognitive Therapy, Department of Psychiatry, University of Pennsylvania, Philadelphia, PA, USA, and Pearson Clinical Assessment (NCS Pearson, Inc.).

Purpose

The primary purpose of the Beck Depression Inventory is to provide a standardized, psychometrically rigorous self-report quantification of the presence and depth of depressive symptomatology over the preceding two-week interval, directly mirroring the diagnostic duration criteria established by modern psychiatric diagnostic taxonomies. Rather than purporting to deliver an isolated, categorical psychiatric diagnosis of major depressive disorder in the absence of clinical interviewing, the instrument is engineered to grade symptom severity across a continuous dimension. It serves clinical, investigative, and epidemiological objectives by isolating the phenotypic severity of core affective, cognitive, somatic, and physiological features characteristic of unipolar depressive episodes.

In clinical practice, the BDI serves four distinct functions. First, it functions as an objective intake and triage instrument within outpatient psychiatric services, community mental health clinics, inpatient psychiatric wards, and primary care environments. By systematically measuring cognitive despair, self-reproach, and physiological dysfunction, clinicians can quickly establish a standardized baseline against which subsequent interventions may be evaluated. Second, the instrument incorporates a dedicated assessment of active and passive suicidal thoughts or wishes (Item 9), providing clinicians with an immediate, high-priority risk-screening indicator that triggers mandatory clinical safety protocols. Third, during active cognitive-behavioral, pharmacological, or somatic therapies (e.g., electroconvulsive therapy or transcranial magnetic stimulation), weekly or bi-weekly readministration of the BDI allows practitioners to map trajectory response curves, detect emerging therapeutic plateaus, and identify residual symptoms that elevate the long-term risk of depressive relapse. Fourth, the Dutch adaptation by van der Does (2002) and international adaptations enable standardized multinational cross-comparisons across psychiatric and medical cohorts.

In empirical psychopathology research, the BDI functions as a premier outcome measure within randomized controlled trials (RCTs) examining novel antidepressants, psychotherapies, neuromodulatory devices, and lifestyle interventions. Its continuous scale sensitivity prevents ceiling and floor artifacts commonly observed in shorter screening scales, permitting the detection of statistically and clinically meaningful effect sizes. Furthermore, it operates extensively in neuroimaging, cognitive experimental psychology, and behavioral genetics studies to correlate neural activation patterns, neuroendocrine profiles (such as hypothalamic-pituitary-adrenal axis dysregulation), and attentional biases with parametric increments in subjective depressive severity.

Psychological Construct

The Beck Depression Inventory measures depression as a multifaceted, coherent psychopathological syndrome comprising distinct yet deeply interrelated symptomatic domains: cognitive distortions, affective dysregulation, behavioral alterations, and somatic-vegetative functional impairments. Beck conceptualized depression not merely as an affective disturbance of mood, but as a systemic cognitive disorder characterized by systematic processing biases and dysfunctional self-appraisals that subsequently activate downstream affective suffering and somatic inhibition.

1. The Cognitive Dimension

The cognitive cluster embedded within the BDI reflects the structural and content-specific distortions that dominate depressive thinking. Items loading onto this domain include:

• Pessimism (Item 2): Reflects negative expectancies regarding the future, feelings of total hopelessness, and the belief that adverse circumstances are unalterable and destined to worsen.
• Past Failure (Item 3): Captures subjective over-attribution of personal inadequacy, viewing one’s autobiographical history as an unremitting succession of avoidable failures.
• Guilty Feelings (Item 5): Measures inappropriate or excessive moral self-condemnation, wherein individuals experience pervasive remorse over perceived commissions or omissions.
• Punishment Feelings (Item 6): Assesses expectations of imminent retributive justice or paranoid-like convictions that current psychological agony is a deserved punitive consequence.
• Self-Dislike (Item 7): Quantifies the erosion of self-esteem, self-regard, and unconditional positive self-acceptance, devolving into active self-loathing.
• Self-Criticalness (Item 8): Captures harsh, rigid hypercritical self-monitoring, where individuals assign total personal blame for external adversities and internal inadequacies.
• Suicidal Thoughts or Wishes (Item 9): Represents the terminal cognitive escape schema, progressing from passive ideation to explicit active intent and planned self-harm.
• Indecisiveness (Item 13): Measures cognitive paralysis, ambivalence, and the perceived inability to choose between alternatives due to excessive fear of committing errors.
• Worthlessness (Item 14): Gauges the categorical collapse of self-worth, wherein the respondent perceives themselves as entirely useless, burdensome, and inferior to peers.
• Concentration Difficulty (Item 19): Quantifies subjective cognitive slowing, executive working memory disruption, and attentional instability that impair daily vocational and social functioning.

2. The Affective-Emotional Dimension

The affective core of the construct targets primary phenomenological shifts in emotional tone, hedonic responsiveness, and distress tolerance:

• Sadness (Item 1): Directly gauges subjective dysphoria, despair, and downheartedness ranging from transient low mood to intolerable, unyielding agony.
• Loss of Pleasure (Item 4): Assesses consummatory and anticipatory anhedonia, reflecting an inability to derive pleasure, joy, or satisfaction from previously rewarding pursuits.
• Crying (Item 10): Measures affective lability or, conversely, affective constriction and emotional blunting, wherein the capacity to cry is entirely extinguished despite internal distress.
• Irritability (Item 17): Assesses lowered frustration tolerance, hypersensitivity to interpersonal friction, and subjective anger outbursts.

3. The Somatic-Vegetative Dimension

Reflecting the neurobiological and vegetative deregulation of limbic and hypothalamic networks, the somatic cluster captures physical depletion, autonomic dysregulation, and altered biological rhythms:

• Agitation (Item 11): Captures psychomotor restlessness, inner motor tension, and the compulsive need for continuous purposeless movement.
• Loss of Interest (Item 12): Assesses interpersonal withdrawal, detachment from social connections, and the collapse of motivational drive.
• Loss of Energy (Item 15): Measures subjective anergia, physical fatigue, and the sensation of systemic exhaustion occurring without exertion.
• Changes in Sleeping Pattern (Item 16): Formulated bidirectionally in the BDI-II to detect both insomnia (initial, middle, or terminal early morning awakening) and atypical hypersomnia.
• Changes in Appetite (Item 18): Bidirectionally measures significant hypophagia (appetite suppression and unintended weight loss) alongside atypical hyperphagia (compulsive food craving).
• Tiredness or Fatigue (Item 20): Quantifies physical fatigability, lethargy, and physical heaviness that impede routine motoric tasks.
• Loss of Interest in Sex (Item 21): Gauges the systemic decline or total cessation of libido and sexual responsiveness.

Theoretical Framework

The Beck Depression Inventory is explicitly grounded in Aaron T. Beck’s landmark Cognitive Theory of Depression (Beck, 1967, 1976, 1987). Historically, Beck formulated this cognitive diathesis-stress paradigm as an empirical refutation of the prevailing psychoanalytic view that conceptualized depression as ‘retroflexed hostility’ or inverted anger directed against the introjected lost love object. Beck noted through systematic clinical observations and early content-analytic studies of depressive dreams that patients consistently exhibited themes of personal deprivation, perceived defeat, defectiveness, and inevitable disaster, rather than inverted hostility.

Central to Beck’s theoretical framework is the Cognitive Triad of Depression, which consists of negative, idiosyncratic cognitive conceptualizations across three major domains:

1. Negative View of the Self: The patient systematically views themselves as fundamentally flawed, inadequate, diseased, socially undesirable, or morally bankrupt (operationalized in BDI items measuring past failure, self-dislike, self-criticalness, and worthlessness).
2. Negative View of the World (Immediate Environment): The patient perceives interpersonal and environmental exchanges as placing excessive, insurmountable demands while presenting unremitting obstacles, hostility, and deprivation (reflected in feelings of punishment and perceived lack of reward).
3. Negative View of the Future: The patient harbors absolute, unwavering expectations that current suffering, deficits, and failures will persist indefinitely, generating pervasive hopelessness (captured in items addressing pessimism and suicidal ideation).

According to cognitive theory, the triad is sustained by underlying depressive schemas—latent, stable cognitive structures acquired during adverse early developmental experiences (such as parental rejection, emotional neglect, or severe loss). While dormant during periods of euthymia, these schemas are activated in adulthood by stress events that psychodynamically or functionally mimic early developmental precipitants. Once activated, these schemas filter, bias, and distort information processing through characteristic cognitive errors (e.g., arbitrary inference, selective abstraction, overgeneralization, dichotomous black-and-white thinking, and personalization).

Consequently, the items within the BDI were deliberately structured to capture these systematic negative cognitive evaluations. The affective, behavioral, and somatic symptoms captured by the scale are conceptualized within Beck’s framework not as the foundational cause of depression, but as direct psychological and neurovegetative consequences triggered by the systemic activation of negative cognitive structures. For instance, psychomotor retardation, energy depletion, and loss of libido stem from the cognitive appraisal that action is futile, while dysphoria and crying emerge as natural affective corollaries to the perceived loss of self-worth and future hope.

Validity

The validity of the Beck Depression Inventory (including both the original 1961 formulation and the definitive 1996 BDI-II revision) has been substantiated through extensive international empirical inquiries spanning psychiatric inpatients, outpatient populations, primary care cohorts, and non-clinical university samples.

1. Content and Face Validity

The content validity of the BDI-II was markedly enhanced relative to the original 1961 version by directly updating items to correspond with the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria for Major Depressive Episode. Items assessing hypochondriasis, body image distortion, weight loss, and somatic preoccupation from the original scale were replaced or modified into contemporary constructs: agitation, feelings of worthlessness, concentration difficulty, and loss of energy. Furthermore, items measuring sleep disturbance and appetite changes were adjusted into bidirectional scoring choices, enabling the scale to capture atypical depressive features (hypersomnia and hyperphagia) in addition to melancholic depressive features.

2. Convergent and Concurrent Validity

Extensive investigations demonstrate strong convergent validity with clinician-rated and alternative self-report depression metrics. In the seminal psychometric standardization study by Beck, Steer, and Brown (1996), the BDI-II exhibited strong positive correlations with the Hamilton Depression Rating Scale (HDRS; r = .71 to .84) and the Revised Hamilton Psychiatric Rating Scale for Depression (r = .73). In a pivotal study by Steer et al. (1999) involving psychiatric outpatients, correlations with the Montgomery-Åsberg Depression Rating Scale (MADRS) were observed between .72 and .79. When evaluated alongside alternative self-report inventories, the BDI-II demonstrates strong convergence with the Center for Epidemiologic Studies Depression Scale (CES-D; r = .81 to .87), the Patient Health Questionnaire-9 (PHQ-9; r = .79 to .85), and the Zung Self-Rating Depression Scale (r = .76 to .83).

3. Discriminant and Divergent Validity

Discriminant validity analyses demonstrate that while the BDI-II correlates moderately with anxiety measures due to shared higher-order negative affectivity (Clark & Watson’s tripartite model), it maintains robust statistical divergence from pure somatic anxiety constructs. Correlations between the BDI-II and the Beck Anxiety Inventory (BAI) typically range from .50 to .62 in psychiatric cohorts, a magnitude substantially lower than its correlations with dedicated depressive measures. When evaluated against the State-Trait Anxiety Inventory (STAI), differential factor and regression analyses consistently demonstrate that BDI-II scores uniquely account for variance in anhedonia, loss of pleasure, and cognitive hopelessness, whereas anxiety inventories uniquely predict physiological hyperarousal and autonomic distress.

4. Criterion and Predictive Validity

Receiver Operating Characteristic (ROC) curve analyses confirm that the BDI-II possesses high diagnostic accuracy for differentiating individuals with major depressive disorder from healthy controls and non-depressed psychiatric patients. In clinical samples evaluated by van der Does (2002) using the Dutch adaptation, areas under the curve (AUC) consistently exceed .90. Using the established clinical cut-off score of 14, sensitivity for detecting major depression ranges between 88% and 94%, with specificity hovering between 82% and 89%. In prospective longitudinal cohorts, baseline BDI-II total scores reliably predict future suicidal behavior, long-term disability, non-remission trajectories, and occupational absenteeism over multi-year follow-up intervals.

Reliability

The Beck Depression Inventory possesses exceptional reliability indices across diverse cultural, demographic, and clinical strata.

1. Internal Consistency

Internal consistency metrics, typically indexed via Cronbach’s alpha (α) and McDonald’s omega (ω), consistently demonstrate high item homogeneity. In Beck, Steer, and Brown’s (1996) normative psychometric standardization manual, the coefficient alpha for the BDI-II was reported as .92 for an outpatient psychiatric cohort (N = 500) and .93 for a collegiate student cohort (N = 120). Subsequent large-scale meta-analyses and validation studies confirm these values:

• Psychiatric Inpatient Samples: Alpha coefficients consistently fall between .91 and .94.
• Psychiatric Outpatient Samples: Alphas range reliably between .90 and .93.
• Medical and Somatic Patient Cohorts: (e.g., chronic pain, oncology, cardiovascular disease) Alphas range between .87 and .91.
• Non-Clinical Community and Student Samples: Alphas range between .86 and .91.
• Dutch Standardization Sample: In the validation study by van der Does (2002), Cronbach’s alpha was .92 in psychiatric cohorts and .88 in healthy community controls, demonstrating full cross-linguistic preservation of reliability.

Item-total correlation coefficients for the 21 items are uniformly robust, with nearly all items demonstrating corrected item-total correlations exceeding .45, and central cognitive items (such as sadness, loss of pleasure, and worthlessness) typically exceeding .65.

2. Test-Retest Stability

Because the BDI-II is sensitive to acute mood fluctuations and therapeutic intervention, test-retest reliability must be contextualized within brief test intervals where clinical stability is expected. In Beck et al.’s (1996) outpatient sample evaluated across a one-week interval prior to treatment initiation, the Pearson product-moment test-retest correlation coefficient was r = .93 (p < .001), indicating high temporal stability without significant practice effects. Over longer observation intervals (e.g., four to six weeks in unmedicated community cohorts), test-retest coefficients remain stable between .70 and .80, reflecting both trait-like vulnerability markers and natural fluctuations in state affect.

Factor Analysis

Extensive exploratory factor analytic (EFA) and confirmatory factor analytic (CFA) studies have scrutinized the internal structural architecture of the Beck Depression Inventory across diverse psychiatric, demographic, and linguistic groups.

1. The Correlated Two-Factor Model

The standard and most replicated structural solution for the BDI-II is a correlated oblique two-factor model, originally established by Beck, Steer, and Brown (1996) and replicated across international adaptations:

• Factor 1: Cognitive-Affective Dimension: Encompasses items reflecting negative cognitive self-evaluation, affective despair, and hedonic loss. Items typically displaying primary loadings (λ > .50) on this factor include: Sadness (Item 1), Pessimism (Item 2), Past Failure (Item 3), Loss of Pleasure (Item 4), Guilty Feelings (Item 5), Punishment Feelings (Item 6), Self-Dislike (Item 7), Self-Criticalness (Item 8), Suicidal Thoughts (Item 9), Indecisiveness (Item 13), and Worthlessness (Item 14).
• Factor 2: Somatic-Vegetative Dimension: Encompasses items tapping physiological disruption, psychomotor agitation, fatigue, and biological vegetative shifts. Items demonstrating primary loadings (λ > .45) include: Loss of Energy (Item 15), Changes in Sleeping Pattern (Item 16), Changes in Appetite (Item 18), Concentration Difficulty (Item 19), Tiredness or Fatigue (Item 20), and Loss of Interest in Sex (Item 21).
• Cross-Loading Items: Items such as Crying (Item 10), Agitation (Item 11), Loss of Interest (Item 12), and Irritability (Item 17) occasionally exhibit moderate loadings across both latent factors depending on whether the clinical cohort is predominantly outpatient, inpatient, or medically compromised.

2. Bifactor Structural Solutions

Modern psychometric investigations employing advanced structural equation modeling (SEM) frequently demonstrate that a bifactor model yields superior statistical fit compared to traditional orthogonal or correlated two-factor models (Ward, 2006; Brouwer et al., 2013). In a bifactor model, each of the 21 items loads significantly onto a single, dominant General Depression Factor (accounting for 70% to 85% of common variance), while simultaneously loading onto distinct, narrower subfactors (e.g., specific cognitive self-blame vs. neurovegetative exhaustion). Typical goodness-of-fit parameters for the bifactor specification across large psychiatric samples satisfy strict psychometric thresholds:

• Comparative Fit Index (CFI): ≥ .95 to .98
• Tucker-Lewis Index (TLI): ≥ .94 to .97
• Root Mean Square Error of Approximation (RMSEA): ≤ .035 to .048 (90% CI [.030, .052])
• Standardized Root Mean Square Residual (SRMR): ≤ .032 to .041

These bifactor findings provide empirical justification for the clinical practice of summing all 21 items into a single, overarching continuous depression severity score, while supporting secondary clinical exploration of somatic versus cognitive-affective profiles.

Instrument / Measurement Tool

The Beck Depression Inventory is a structured clinical self-report measurement instrument. Below are the architectural specifications of the tool:

• Test Type: Standardized psychological self-report rating scale.
• Administration Format: Paper-and-pencil questionnaire, supervised clinical administration, or secure computerized digital assessment.
• Target Population: Adolescents and adults aged 13 years and older, possessing at least a fifth-grade reading comprehension level.
• Administration Time: Typically completed in 5 to 10 minutes.
• Time Frame Assessed: The preceding two weeks, including the day of administration (aligning with DSM-IV/DSM-5 major depressive episode duration criteria).
• Item Composition: Exactly 21 item groups, each focusing on a distinct clinical symptom domain.
• Response Scale: 4-point severity rating scale for each item group, scored 0 to 3. Each numerical response option is paired with a distinct, clinically nuanced phenomenological statement representing incremental symptom severity. (Items 16 and 18 contain bidirectional sub-options yielding 7 potential statements, yet remain strictly scored on a 0 to 3 severity continuum).
• Scoring Procedure:
  • The administrator or scoring algorithm sums the endorsed numerical value (0, 1, 2, or 3) selected for each of the 21 symptom groups.
  • If a respondent endorses multiple statements within a single item group, the statement corresponding to the highest numerical severity score is retained for total calculation.
  • The cumulative score ranges from an absolute minimum of 0 to a theoretical maximum of 63 points.
  • There are no reverse-scored items.
• Standard Cut-Off Thresholds (Beck, Steer, & Brown, 1996; van der Does, 2002):
  • 0–13: Minimal depression (scores within this range are typical of healthy non-clinical populations).
  • 14–19: Mild depression (indicates clinically notable mild depressive distress requiring monitoring).
  • 20–28: Moderate depression (indicates clinically significant depressive symptomatology requiring diagnostic workup and intervention).
  • 29–63: Severe depression (reflects intense, potentially disabling depressive psychopathology requiring immediate clinical attention).
• Critical Clinical Safety Flag: Item 9 (Suicidal Thoughts or Wishes) functions as an immediate clinical safety alert. Any score greater than 0 (i.e., endorsing option 1, 2, or 3) mandates a formal clinical suicide risk assessment regardless of the cumulative overall score.

Permissions & Fee and Test Year

The Beck Depression Inventory has evolved through several distinct iterations across modern psychometric history:

• 1961: Original publication by Aaron T. Beck, C. H. Ward, M. Mendelson, J. Mock, and J. Erbaugh in the Archives of General Psychiatry.
• 1979: First major copyright revision (BDI-1A), co-authored by Beck, Rush, Shaw, and Emery, standardizing item stems and standardizing administration formats.
• 1996: Comprehensive diagnostic modernization resulting in the BDI-II (Beck, Steer, & Brown), aligning items with DSM-IV criteria and adopting a two-week evaluation timeframe.
• 2002: Publication of the official Dutch manual and standardization (BDI-II-NL) by A. J. Willem van der Does.

Copyright and Licensing Terms: The BDI, BDI-II, and its authorized translations are proprietary, copyrighted psychological instruments owned exclusively by NCS Pearson, Inc. and distributed globally through Pearson Clinical Assessment. The instrument is not in the public domain and is subject to licensing fees. Qualified healthcare professionals, psychological researchers, and clinical institutions must purchase official test booklets, digital administration tokens (via Pearson’s Q-global web-based platform), or formal institutional research permissions. Access requires a minimum Qualification Level B (requiring formal master’s-level training in psychometrics, psychological testing, clinical psychology, psychiatry, or closely allied disciplines).

References

Beck, A. T. (1967). Depression: Causes and treatment. University of Pennsylvania Press. https://doi.org/10.9783/9780812200591

Beck, A. T. (1976). Cognitive therapy and the emotional disorders. International Universities Press.

Beck, A. T. (1987). Cognitive models of depression. Journal of Cognitive Psychotherapy: An International Quarterly, 1(1), 5–37.

Beck, A. T., Steer, R. A., & Brown, G. K. (1996). Manual for the Beck Depression Inventory-II. Psychological Corporation. https://doi.org/10.1037/t00742-000

Beck, A. T., Ward, C. H., Mendelson, M., Mock, J., & Erbaugh, J. (1961). An inventory for measuring depression. Archives of General Psychiatry, 4(6), 561–571. https://doi.org/10.1001/archpsyc.1961.01710120031004

Brouwer, D., Meijer, R. R., & Zevalkink, J. (2013). On the factor structure of the Beck Depression Inventory-II: Validation, calibration, and construct validity in a Dutch outpatient sample. Journal of Affective Disorders, 149(1–3), 209–216. https://doi.org/10.1016/j.jad.2013.01.026

Clark, L. A., & Watson, D. (1991). Tripartite model of anxiety and depression: Psychometric evidence and taxonomic implications. Journal of Abnormal Psychology, 100(3), 316–336. https://doi.org/10.1037/0021-843X.100.3.316

Steer, R. A., Ball, R., Ranieri, W. F., & Beck, A. T. (1999). Dimensions of the Beck Depression Inventory-II in clinically depressed outpatients. Journal of Clinical Psychology, 55(1), 117–128. https://doi.org/10.1002/(sici)1097-4679(199901)55:1<117::aid-jclp12>3.0.co;2-a

van der Does, A. J. W. (2002). Handleiding voor de Beck Depression Inventory: Second Edition (BDI-II-NL) [Manual for the Beck Depression Inventory-Second Edition Dutch version]. Swets & Zeitlinger / Pearson Assessment.

Ward, L. C. (2006). Comparison of factor analytic models of the Beck Depression Inventory–II. Psychological Assessment, 18(1), 81–88. https://doi.org/10.1037/1040-3590.18.1.81

13. Items of the Scale (Questionnaire)