Treatment Self-Regulation Questionnaire TSRQ

Abstract

The Treatment Self-Regulation Questionnaire (TSRQ) is a widely utilized psychometric instrument developed within the conceptual architecture of Self-Determination Theory (SDT) to evaluate the motivational orientations governing an individual’s engagement in health-promoting behaviors, therapeutic regimens, and medical self-management. Originally conceptualized by Geoffrey C. Williams and colleagues in 1996 to examine weight-loss maintenance, the TSRQ has been adapted across numerous chronic disease contexts, most notably type 2 diabetes mellitus (TSRQ-Diabetes), smoking cessation, cardiovascular risk reduction, and pharmacological adherence. The standard instrument operationalizes behavioral regulation along the SDT organismic integration continuum, primarily contrasting Autonomous Regulation (behaviors executed out of intrinsic interest, personal congruence, and internalized health values) against Controlled Regulation (behaviors driven by external compliance pressures, interpersonal approval, guilt, or avoidance of shame). In specific healthcare contexts, an Amotivation subscale is also employed to capture the absence of intentionality or perceived self-efficacy. Comprising between 13 and 19 items depending on disease-specific behavioral targets, the TSRQ uses a 7-point Likert response scale ranging from 1 (“not at all true”) to 7 (“very true”). Psychometric evaluations across diverse clinical cohorts consistently confirm high internal consistency reliability (Cronbach’s alpha coefficients routinely ranging from α = .80 to .93 for autonomous regulation and α = .73 to .87 for controlled regulation), robust factorial validity supported by exploratory and confirmatory factor analyses, and notable predictive validity. Autonomous regulation scores derived from the TSRQ reliably predict sustained physiological outcomes, including clinically meaningful decreases in glycosylated hemoglobin (HbA1c), prolonged smoking abstinence, adherence to physical activity recommendations, and sustained lifestyle changes. This paper provides an exhaustive academic analysis of the TSRQ’s theoretical foundation, psychometric architecture, structural validity, scoring algorithms, and clinical utility.

Keywords

Treatment Self-Regulation Questionnaire, TSRQ, Self-Determination Theory, autonomous regulation, controlled regulation, relative autonomy index, diabetes self-management, health behavior change, medication adherence, intrinsic motivation

Authors

The Treatment Self-Regulation Questionnaire was conceptualized, validated, and iteratively refined by a distinguished consortium of clinical health psychologists and motivational theorists affiliated with the University of Rochester and affiliated medical centers:

• Geoffrey C. Williams, M.D., Ph.D. – Professor Emeritus of Medicine, Psychiatry, and Psychology, Department of Medicine and Clinical and Social Sciences in Psychology, University of Rochester Medical Center, Rochester, New York, United States. Dr. Williams has been the primary investigator in pioneering the application of Self-Determination Theory to clinical medicine, patient autonomy support, and chronic disease self-management.
• Richard M. Ryan, Ph.D. – Professor at the Institute for Positive Psychology and Education, Australian Catholic University, Sydney, Australia, and Research Professor Emeritus, Department of Clinical and Social Sciences in Psychology, University of Rochester. Dr. Ryan is the co-founder of Self-Determination Theory.
• Edward L. Deci, Ph.D. (1942–2023) – Helen F. and Fred H. Gowen Professor of Psychology Emeritus, Department of Clinical and Social Sciences in Psychology, University of Rochester. Dr. Deci is the foundational co-originator of Self-Determination Theory alongside Dr. Ryan.
• Virginia M. Freedman, Ph.D. – Research Professor, Institute for Social Research, University of Michigan, Ann Arbor, Michigan; previously affiliated with clinical trials on diabetes and chronic illness self-regulation at the University of Rochester.
• Richard W. Kouides, M.D. – Clinical Professor of Medicine, University of Rochester School of Medicine and Dentistry; Medical Director, Rochester General Hospital Hematology/Oncology programs.
• Vernon M. Grow, Ph.D. – Clinical psychologist and research collaborator on initial longitudinal studies assessing motivation and long-term weight-loss maintenance.

Inquiries regarding the theoretical development, authorized translations, and clinical research permissions for the TSRQ and related SDT healthcare instruments are centrally curated through the Center for Self-Determination Theory.

Purpose

The primary clinical and psychometric purpose of the Treatment Self-Regulation Questionnaire (TSRQ) is to identify, differentiate, and quantify the specific qualities of human motivation that prompt patients to initiate, comply with, or abandon complex health behaviors and prescribed medical regimens. In contemporary clinical medicine, chronic condition management rarely depends exclusively on acute pharmacological interventions; instead, it demands prolonged, difficult, and multifaceted behavioral adaptations. Conditions such as diabetes mellitus, essential hypertension, morbid obesity, coronary artery disease, and substance use disorders require individuals to radically modify entrenched routines related to diet, daily physical activity, blood glucose self-monitoring, and strict pharmacological schedules. Traditional biomedical models often conceptualize patient compliance in binary terms (adherent versus non-adherent), completely ignoring the psychological mechanisms that drive sustained behavioral commitment.

The TSRQ bridges this critical gap by measuring the underlying self-regulatory reasons why an individual undertakes a target behavior. Self-Determination Theory posits that the clinical stability and permanence of a lifestyle modification are fundamentally shaped by the degree of self-determination or internalization supporting that behavior. When patients engage in health regimens purely because of external pressures—such as spousal coercion, social surveillance, doctor-mediated fear, or internal neurotic guilt (introjected regulation)—the behavioral change tends to be fragile, sporadic, and prone to rapid relapse under psychological stress. Conversely, when patients perceive the health regimen as coherent with their authentic life values, personal autonomy, and aspirations for vitality (identified and integrated regulation), they exhibit superior longitudinal treatment persistence, resilience in the face of setbacks, and enhanced psychological well-being.

In research environments, the TSRQ functions as a primary mediator variable in randomized controlled trials (RCTs) evaluating the efficacy of clinician communication interventions, such as motivational interviewing, autonomy-supportive physician counseling, and self-management education programs. By deploying the TSRQ longitudinally, investigators can ascertain whether an intervention successfully moved patients along the self-determination continuum, and whether that psychological shift subsequently explains improvements in objective biomedical markers (e.g., reductions in serum HbA1c, systolic blood pressure, or low-density lipoprotein cholesterol). In daily clinical diagnostics, the TSRQ provides clinicians with actionable psychological profiles, enabling multidisciplinary healthcare teams to identify patients who, despite outward compliance, remain at high risk of treatment abandonment due to underlying controlled motivation.

Psychological Construct

The psychological construct operationalized by the TSRQ is behavioral regulation within the domain of personal healthcare and therapeutic adherence. Rather than conceptualizing motivation as a unitary, quantitative continuum ranging from “unmotivated” to “highly motivated,” the TSRQ measures qualitatively distinct regulatory styles rooted in the degree to which an external demand has been internalized into the individual’s core sense of self. The instrument captures three primary regulatory dimensions:

1. Autonomous Regulation

Autonomous regulation represents the most self-determined form of motivation for health-related behavior. It synthesizes two advanced developmental phases along the organismic integration continuum:

• Identified Regulation: The individual consciously values the health goal or treatment practice, endorsing it as personally meaningful and significant. For example, a patient self-administers insulin not because someone else demands it, but because they understand and value its role in safeguarding their long-term health and preserving their vision and kidney function.
• Integrated Regulation: The health behavior is fully assimilated into the person’s overarching value system, self-concept, and philosophy of life. The patient identifies as someone who actively nurtures their physical vitality, rendering adherence a harmonious, non-conflictual lifestyle choice.
• Intrinsic Motivation: Although less common in arduous chronic disease routines, intrinsic motivation reflects performing an activity for its inherent satisfaction, challenge, or intellectual curiosity (e.g., finding personal enjoyment in culinary experimentation with low-glycemic foods or savoring the physical sensation of daily exercise).

In the TSRQ-Diabetes, autonomous regulation is tapped by statements such as: “I personally believe that controlling my diabetes will improve my health” and “Exercising regularly and following my diet are choices I really want to make.”

2. Controlled Regulation

Controlled regulation encompasses behaviors that are energized and directed by psychological pressures perceived as external to the self. Within the TSRQ, this construct is an aggregate of two less internalized regulatory styles:

• External Regulation: The most overt form of non-autonomous motivation, wherein actions are performed exclusively to satisfy an external contingency, secure an interpersonal reward, or avoid punishment and social reprimand. In clinical contexts, patients exhibit external regulation when they follow their dietary restrictions solely to avoid being chastised by their physician or to satisfy demands made by their family members.
• Introjected Regulation: The individual has partially taken in an external rule, but has not integrated it as their own. Behaviors are executed under the duress of internal pressures, such as conditional self-esteem, intense anticipated guilt, anxiety, or the dread of shame. A patient exhibiting introjected regulation checks their blood glucose primarily because they would feel like an absolute moral failure or experience self-reproach if they failed to follow instructions.

Controlled items on the TSRQ include: “Other people would be mad at me if I didn’t” and “I would feel guilty if I didn’t do what my doctor said.” Because controlled reasons are multifaceted, psychometric batteries typically feature a broader array of controlled items to adequately represent interpersonal coercion and intrapsychic guilt.

3. Amotivation

Amotivation constitutes the non-regulation pole of the self-determination continuum, marked by a complete lack of intentionality, behavioral inertia, and feelings of utter incompetence. In amotivated states, an individual perceives no viable link between their actions and clinical outcomes, viewing treatment regimens as futile or unmanageable. While omitted from shorter clinical forms of the TSRQ (such as the 19-item diabetes version) due to low variance in treatment-seeking clinical populations, amotivation subscales are selectively introduced in public health contexts, smoking cessation trials, and addiction clinics where non-adherence and denial are prominent clinical features.

Theoretical Framework

The TSRQ is directly derived from Self-Determination Theory (SDT), a macro-theory of human motivation, personality development, and psychological wellness established by Edward L. Deci and Richard M. Ryan. Specifically, the questionnaire is built upon two of SDT’s mini-theories: Organismic Integration Theory (OIT) and Basic Psychological Needs Theory (BPNT).

Organismic Integration Theory (OIT)

OIT posits that human beings are naturally active, growth-oriented organisms possessing an innate tendency toward assimilating external regulations and values into a cohesive sense of self. The internalization process is conceptualized not as an all-or-nothing phenomenon, but as a formal continuum of self-determination reflecting progressive levels of autonomy:

1. Amotivation: Lack of intentional action; characterized by perceived helplessness.
2. External Regulation: Salience of extrinsic rewards and punishments; compliance is dependent on active external surveillance.
3. Introjected Regulation: Ego-involvement; internal rewards of pride and defensive avoidance of guilt, shame, and self-derogation.
4. Identified Regulation: Conscious valuing of the behavioral goal; perceived personal importance.
5. Integrated Regulation: Hierarchical alignment of behavioral regulations with broader identities and life goals.
6. Intrinsic Regulation: Inherent enjoyment, satisfaction, and interest.

The TSRQ operationalizes these theoretical distinctions for the medical setting. Because prescribed medical tasks (e.g., taking antihypertensive medications, executing subcutaneous insulin injections) rarely provide intrinsic hedonic pleasure, the critical regulatory transition occurs when a patient moves from controlled regulation (external and introjected) to autonomous regulation (identified and integrated).

Basic Psychological Needs Theory (BPNT)

SDT postulates that psychological internalization and sustained self-regulation are contingent on the satisfaction of three universal, innate psychological needs:

• Autonomy: The experience of volition, psychological freedom, and personal agency over one’s behavioral trajectory.
• Competence: The experience of effectiveness, mastery, and capability in carrying out medical tasks and navigating treatment hurdles.
• Relatedness: The experience of mutual warmth, empathetic understanding, respect, and unconditional positive regard from clinical providers and social circles.

Within the SDT healthcare model, when healthcare providers create an autonomy-supportive climate—acknowledging patient perspectives, offering therapeutic rationales, eliciting personal choices, and avoiding punitive guilt-trips—patients experience need satisfaction. This need satisfaction fuels the psychological internalization captured by the TSRQ, transitioning the patient toward robust autonomous regulation.

Validity

The psychometric validity of the TSRQ has been rigorously established across more than three decades of empirical testing, spanning clinical health psychology, behavioral medicine, and preventive cardiology.

Construct and Structural Validity

Construct validity has been repeatedly substantiated across multiple health domains, confirming that autonomous and controlled subscales function as distinct, internally coherent theoretical dimensions rather than polar opposites on a single spectrum. Cross-sectional and longitudinal correlation matrices demonstrate quasi-simplex patterns conforming to SDT postulates: subscales situated adjacent to one another along the self-determination continuum (e.g., identified items and intrinsic challenge items) correlate more positively with one another than with distant constructs (e.g., external coercion items). Structural equation modeling (SEM) has confirmed that the autonomous and controlled dimensions capture unique latent variances across distinct behavioral stems, such as taking medications versus executing lifestyle modifications.

Predictive and Criterion-Related Validity

The predictive validity of the TSRQ is exceptionally strong across a range of objective biological, behavioral, and clinical endpoints:

• Glycemic Control in Diabetes: In the landmark validation study by Williams, Freedman, and Deci (1998) involving patients with type 1 and type 2 diabetes mellitus, autonomous regulation measured by the TSRQ-Diabetes was significantly correlated with objective physiological markers. Longitudinal paths revealed that increases in autonomous regulation over a 12-month period predicted marked reductions in glycosylated hemoglobin (HbA1c), with an effect size that remained significant even after controlling for baseline HbA1c, patient demographics, and prior medical history. Conversely, controlled regulation failed to predict glycemic improvement and was associated with higher diabetes-related emotional distress.
• Weight-Loss Maintenance: In the foundational clinical investigation by Williams, Grow, Freedman, Ryan, and Deci (1996), morbidly obese outpatients entering a 6-month, very-low-calorie medically supervised weight-loss program completed the TSRQ at baseline and at mid-treatment. Patients who possessed higher autonomous regulation attended more clinical sessions, lost significantly more weight over the intervention period, and, most crucially, demonstrated superior maintenance of weight loss at a 23-month post-treatment follow-up. Controlled regulation predicted premature program dropout and rapid weight regain.
• Smoking Cessation: In a clinical trial involving over 1,000 adult smokers (Williams, Cox, Kouides, & Deci, 1999; Williams et al., 2002), autonomous regulation on the TSRQ smoking version predicted biochemically verified 6-month continuous tobacco abstinence (validated via expired carbon monoxide and serum cotinine assays), displaying an odds ratio exceeding 1.70 per standard deviation increase in autonomous regulation.
• Pharmacological Adherence: Across cardiovascular and chronic pulmonary cohorts, autonomous regulation has consistently demonstrated positive correlations with microelectronic pill-cap monitoring (MEMS) adherence rates and pharmacy refill records (r values ranging from .28 to .46), while controlled regulation exhibited null or negative relationships with objective adherence metrics.

Convergent and Discriminant Validity

Convergent validity is documented via strong, expected associations between TSRQ autonomous regulation and theoretically convergent psychometric instruments, including the General Causality Orientations Scale (GCOS) Autonomy Orientation subscale (r = .35 to .48), the Health Care Climate Questionnaire (HCCQ) measuring perceived physician autonomy support (r = .40 to .55), and generalized self-efficacy scales. Discriminant validity has been shown through minimal or zero correlations with socially desirable responding (measured via the Marlowe-Crowne Social Desirability Scale), trait neuroticism, and baseline socioeconomic status.

Reliability

The TSRQ exhibits robust internal consistency and temporal stability across diverse clinical settings, patient populations, and linguistic adaptations.

Internal Consistency Reliability

Across numerous empirical investigations, Cronbach’s alpha (α) coefficients for the primary subscales routinely exceed the widely accepted psychometric benchmark of .70:

• Autonomous Regulation Subscale: Internal consistency is exceptionally high. In the original diabetes cohort (Williams et al., 1998), alpha coefficients for autonomous regulation across medications/glucose monitoring and diet/exercise stems were α = .81 and α = .85, respectively. In the comprehensive psychometric synthesis by Levesque et al. (2007) evaluating the TSRQ across three health behaviors (healthy eating, physical activity, and smoking cessation), autonomous regulation demonstrated alphas ranging from α = .85 to .93.
• Controlled Regulation Subscale: The controlled regulation subscale likewise maintains acceptable to high internal consistency, typically reported between α = .73 and α = .87. The inclusion of additional items representing varied manifestations of controlled motivation (e.g., social disapproval, guilt, external obedience) ensures that the subscale adequately samples the multifaceted nature of introjection and external contingency without compromising reliability.
• Amotivation Subscale (when included): In instruments incorporating the amotivation construct, reported internal consistency ranges from α = .71 to .82 across clinical and community samples.

Test-Retest Reliability and Temporal Stability

Because the TSRQ measures psychological states of behavioral regulation that are expected to respond dynamically to clinical interventions and provider communication, test-retest reliability must be examined in stable, non-interventional cohorts. In observational control arms over 4- to 12-week test-retest intervals, stability coefficients range between r = .74 and r = .83, demonstrating strong temporal stability in the absence of targeted autonomy-supportive educational or behavioral interventions.

Factor Analysis

The latent structural integrity of the TSRQ has been extensively investigated using both Exploratory Factor Analysis (EFA) and Confirmatory Factor Analysis (CFA).

Exploratory Factor Structure

Early factor analytic work by Williams et al. (1996, 1998) utilized principal components and principal axis factoring with both orthogonal (Varimax) and oblique (Promax/Oblimin) rotations. Across distinct behavioral stems, the scree plots and eigenvalue criteria (λ > 1.0) consistently revealed a two-factor dominant solution corresponding precisely to Autonomous Regulation and Controlled Regulation. Items designed to tap personal importance, health values, and choice loaded strongly on the autonomous factor (factor loadings ranging from .55 to .84), with minimal cross-loadings on the controlled factor (loadings < .25). Conversely, items measuring social compliance, external surveillance, and internal guilt loaded cleanly onto the controlled factor (loadings ranging from .48 to .81).

Confirmatory Factor Analysis (CFA) and Model Fit

In an authoritative cross-behavioral validation study, Levesque et al. (2007) conducted rigorous Confirmatory Factor Analyses across multiple independent clinical and community samples (N > 1,000 per sample) to compare alternative structural configurations of the TSRQ. A two-factor oblique model (Autonomous vs. Controlled) and a three-factor model (Autonomous, Controlled, and Amotivation) were tested against a unitary single-factor model. The single-factor model demonstrated poor fit to the empirical data (χ²/df > 8.0, CFI < .75, RMSEA > .11).

Conversely, the hypothesized multidimensional models demonstrated excellent model fit indices across distinct health domains (physical activity, dietary regulation, and smoking abstinence):

• Comparative Fit Index (CFI): Values consistently spanned from .93 to .97, exceeding the standard ≥ .90 threshold for acceptable fit and approaching the stringent .95 standard.
• Tucker-Lewis Index (TLI): Coefficients ranged between .92 and .96.
• Root Mean Square Error of Approximation (RMSEA): Point estimates ranged from .042 to .061, with the 90% confidence intervals staying well below the .08 ceiling.
• Standardized Root Mean Square Residual (SRMR): Values ranged between .038 and .054, confirming minimal residual variance.

Factorial invariance testing further corroborated that the TSRQ exhibits metric and scalar measurement invariance across genders, age strata, and varying clinical disease severities, confirming that mean score differences between demographic groups reflect authentic differences in underlying motivational regulation rather than measurement bias.

Instrument / Measurement Tool

The Treatment Self-Regulation Questionnaire is an adaptable, self-administered psychometric instrument designed to assess motivation across specific medical and health-promoting behaviors. Below is a structured technical specification of the instrument, with specific focus on the validated 19-item Diabetes Version (TSRQ-Diabetes):

• Instrument Name: Treatment Self-Regulation Questionnaire (TSRQ); specific module: Treatment Questionnaire Concerning Diabetes (TSRQ-Diabetes).
• Administration Mode: Paper-and-pencil self-report questionnaire, digital survey platform, or clinician-assisted interview.
• Target Population: Adolescents and adults diagnosed with type 1 or type 2 diabetes mellitus, metabolic syndrome, or individuals managing complex lifestyle and medication regimens.
• Administration Time: Approximately 5 to 8 minutes.
• Item Count: 19 items across two discrete behavioral stems:
• Stem A: “I take my medications for diabetes and/or check my glucose because:” (Items 1 to 8; 8 items total).
• Stem B: “The reason I follow my diet and exercise regularly is that:” (Items 9 to 19; 11 items total).
• Response Format: 7-point Likert scale formatted as:
• 1 = Not at all true
• 2 = [Anchor between not at all true and somewhat true]
• 3 = [Anchor between not at all true and somewhat true]
• 4 = Somewhat true
• 5 = [Anchor between somewhat true and very true]
• 6 = [Anchor between somewhat true and very true]
• 7 = Very true
• Subscale Composition & Scoring Architecture:
• Autonomous Regulation Subscale (8 items): Calculated as the arithmetic mean of items 2, 3, 7 (under Stem A) and items 10, 13, 16, 18, 19 (under Stem B). Higher scores reflect greater self-determined motivation and internalized endorsement of diabetes self-management.
• Controlled Regulation Subscale (11 items): Calculated as the arithmetic mean of items 1, 4, 5, 6, 8 (under Stem A) and items 9, 11, 12, 14, 15, 17 (under Stem B). Higher scores reflect greater regulation driven by external rewards, fear of disapproval, compliance, or internalized guilt and shame.
• Subscale Breakdown by Stem: Researchers may also compute separate autonomous and controlled regulation subscale scores for Medication/Glucose Testing (Stem A: Autonomous = Items 2, 3, 7; Controlled = Items 1, 4, 5, 6, 8) and Diet/Exercise (Stem B: Autonomous = Items 10, 13, 16, 18, 19; Controlled = Items 9, 11, 12, 14, 15, 17) to examine behavioral discrepancies.
• Relative Autonomy Index (RAI): When an integrated, composite metric is required for path modeling or regression analysis, an RAI can be calculated by subtracting the overall Controlled Regulation mean score from the overall Autonomous Regulation mean score:
  RAI = Mean(Autonomous Regulation) − Mean(Controlled Regulation). Positive scores denote predominantly autonomous self-regulation, whereas negative scores denote predominantly controlled regulation.

Permissions & Fee and Test Year

The Treatment Self-Regulation Questionnaire was first introduced in clinical literature in 1996 by Dr. Geoffrey C. Williams and co-investigators in their foundational study on weight-loss maintenance published in the Journal of Personality and Social Psychology, followed by the formal validation of the diabetes-specific version in 1998 published in Diabetes Care.

In accordance with the open-science principles maintained by the founders of Self-Determination Theory, the TSRQ is made available free of charge for non-commercial, academic, scientific, and educational research purposes. Formal licensing fees, registration barriers, and commercial royalties are waived for individual researchers, healthcare institutions, and university faculties. Investigators are permitted to adapt the target behavioral stems to correspond with specific medical regimens (e.g., hemodialysis adherence, antiretroviral therapy compliance, cardiac rehabilitation) provided that the theoretical structure of the scale is preserved and standard academic citations are maintained.

For commercial health-coaching applications, proprietary corporate interventions, digital mobile applications, or pharmaceutical industry clinical trials, inquiries regarding commercial licensing agreements should be directed through the Center for Self-Determination Theory.

References

Below are primary academic references documenting the theoretical development, validation, and clinical application of the Treatment Self-Regulation Questionnaire:

• Deci, E. L., & Ryan, R. M. (1985). Intrinsic motivation and self-determination in human behavior. Plenum Press. https://doi.org/10.1007/978-1-4899-2271-7
• Deci, E. L., & Ryan, R. M. (2000). The “what” and “why” of goal pursuits: Human needs and the self-determination of behavior. Psychological Inquiry, 11(4), 227–268. https://doi.org/10.1207/S15327965PLI1104_01
• Levesque, C. S., Williams, G. C., Elliot, D., Pickering, M. A., Bodenhamer, B., & Finley, P. J. (2007). Validating the Treatment Self-Regulation Questionnaire (TSRQ) across three different health behaviors. Health Education Research, 22(5), 691–706. https://doi.org/10.1093/her/cyl148
• Ryan, R. M., & Deci, E. L. (2017). Self-determination theory: Basic psychological needs in motivation, development, and wellness. Guilford Press. https://doi.org/10.1521/978.14625/28769
• Williams, G. C., Cox, H. N., Kouides, R., & Deci, E. L. (1999). Presenting the facts about smoking to adolescents: Effects of an autonomy-supportive style. Archives of Pediatrics & Adolescent Medicine, 153(9), 959–964. https://doi.org/10.1001/archpedi.153.9.959
• Williams, G. C., Freedman, V. M., & Deci, E. L. (1998). Supporting autonomy to promote patients’ self-management of diabetes. Diabetes Care, 21(10), 1644–1651. https://doi.org/10.2337/diacare.21.10.1644
• Williams, G. C., Grow, V. M., Freedman, Z. R., Ryan, R. M., & Deci, E. L. (1996). Motivational predictors of weight loss and weight-loss maintenance. Journal of Personality and Social Psychology, 70(1), 115–126. https://doi.org/10.1037/0022-3514.70.1.115
• Williams, G. C., McGregor, H. A., Sharp, D., Levesque, C., Kouides, R. W., Ryan, R. M., & Deci, E. L. (2006). Testing a self-determination theory intervention for motivating tobacco cessation: Supporting autonomy and competence in a clinical trial. Health Psychology, 25(1), 91–101. https://doi.org/10.1037/0278-6133.25.1.91
• Williams, G. C., Minicucci, D. S., Kouides, R. W., Levesque, C. S., Weiss, K. G., Freedman, Z. R., Lynch, M. F., & Deci, E. L. (2002). Self-determination, smoking, diet, and exercise in the primary care setting. Preventive Medicine, 34(3), 324–334. https://doi.org/10.1006/pmed.2001.0991

13. Items of the Scale (Questionnaire)