Evaluating the impact of individuals' morningness-eveningness on the effectiveness of a habit-formation intervention for a simple and a complex behavior.

Planning-based interventions are often used to help individuals form habits. Existing literature suggests a one-size-fits all approach to habit formation, but planning interventions may be optimized if tailored to individual differences and/or behavioral complexity. We test the hypothesis that planning to do a relatively complex behaviour (exercise) at a time that matches an individuals' diurnal preference will facilitate behavioral engagement; whereas for a simpler behaviour (calcium supplementation), the optimal time-of-day for a new behavior will occur in the morning. Young, women volunteers (N = 317) were randomly assigned to take calcium supplements or to exercise for 4 weeks and to control (no planning) or to one of three planning interventions (morning plan; evening plan; unassigned-time plan). Participants reported diurnal preference at baseline and habit strength and behavioral frequency weekly. Fitbit Zips and Medication Event Monitoring System Caps (MEMS) were used to objectively assess behavioral engagement. Multilevel modelling found that calcium-supplementation was greatest for morning-types in the morning-cue condition, whereas exercise was greatest for morning-types with morning cues and evening-types with evening cues. Habit-formation strategies may depend on diurnal preference and behavioral complexity. Future research can evaluate the role of other individual differences.

Feasibility and preliminary efficacy of a theory-informed resistance exercise training single-arm intervention for major depression.

Many adults with major depressive disorder (MDD) do not receive effective treatment. The potential benefits of resistance exercise training (RET) are understudied and may be mechanistically related to cerebral blood flow changes. PURPOSE: To assess feasibility, acceptability, and preliminary efficacy of a 16-week, theory-informed RET trial for the treatment of MDD and explore changes in cerebral blood flow. METHODS: Ten adults with DSM-5-diagnosed MDD were enrolled in a single-arm, 16-week, twice-weekly, whole-body RET intervention, consistent with US and WHO Physical Activity resistance exercise guidelines. To build intrinsic motivation and develop exercise-preparatory habits, motivators and commitment were discussed weekly. Screening, enrollment, and intervention attendance and compliance rates documented feasibility. At baseline and weeks 8, 16, and 26, current MDD diagnosis, clinician-rated, and self-reported symptom severity were evaluated along with cerebral blood flow which was assessed as middle cerebral artery (MCA) mean blood velocity, conductance, and pulsatility. RESULTS: Nine participants completed the intervention. Strong feasibility and acceptability (98 % adherence, 93 % compliance, and 90 % retention) were found. MDD remission was reached by 8/9 participants at week 16 and persisted through week 26. There were large decreases in clinician-rated and self-reported symptoms at each assessment (Hedges' g = 0.84-2.13). There were small-to-moderate increases in MCA velocity (g = 0.32-0.57) and conductance (g = 0.20-0.76) across time, with minimal changes in pulsatility (all g < 0.21). CONCLUSIONS: Preliminary results suggest RET for MDD treatment is feasible and plausibly efficacious, finding large antidepressant effects. A sufficiently powered randomized controlled trial to assess RET's efficacy for treating MDD via potential cerebrovascular mechanisms is warranted.

'She thought the same way I that I thought:' a qualitative study of patient-provider concordance among Gulf War Veterans with Gulf War Illness.

Objective: Medically unexplained symptoms (MUS), such as chronic fatigue syndrome, irritable bowel syndrome, and Gulf War Illness (GWI), are difficult to treat. Concordance-shared understanding between patient and provider about illness causes, course, and treatment-is an essential component of high-quality care for people with MUS. This qualitative paper focuses on the experiences of United States military Veterans living with GWI who have endured unique healthcare challenges. Methods & Measures: Qualitative interviews were conducted with 31 Veterans with GWI to explore factors that contribute to and detract from concordance with their Veteran Affairs (VA) healthcare providers. In addition to being seen by VA primary care, over half of participants also sought care at a War Related Illness and Injury Study Center, which specializes in post-deployment health. Deductive and inductive codes were used to organize the data, and themes were identified through iterative review of coded data. Results: Major themes associated with patient-provider concordance included validation of illness experiences, perceived provider expertise in GWI/MUS, and trust in providers. Invalidation, low provider expertise, and distrust detracted from concordance. Conclusion: These findings suggest providers can foster concordance with MUS patients by legitimizing patients' experiences, communicating knowledge about MUS, and establishing trust.

The role of agricultural drainage, storm-events, and natural filtration on the biogeochemical cycling capacity of aquatic and sediment environments in Lake Erie's drainage basin.

Lake Erie is the most at risk of the Great Lakes for degraded water quality due to non-point source pollution caused by agricultural activities in the lake's watershed. The extent and temporal patterns of nutrient loading from these agricultural activities is influenced by the timing of agronomic events, precipitation events, and water flow through areas of natural filtration within the watershed. Downstream impacts of these nutrient loading events may be moderated by the co-loading of functionally relevant biogeochemical cycling microbial communities from agricultural soils. This study quantified loading patterns of these communities from tile drain sources, assessed whether functional communities from agricultural sources influenced downstream microbial functionality, and investigated how distance from agricultural sources, storm events, and areas of natural filtration altered nutrient cycling and nutrient fluxes in aquatic and sediment environments. Water and sediment samples were collected in the Wigle Creek watershed in Ontario, from tile drains through to Lake Erie, from May to November 2021, and microbial nitrogen (N) and phosphorous (P) cycling capacity (quantitative PCR), and nutrient levels were evaluated. Results showed that N and P functional groups were co-loaded with nutrients, with increased loading occurring during storm events and during agricultural activities including fertilization and harvest. Overall functional capacity in the aquatic environment decreased with distance from the agricultural sources and as water transited through natural filtration areas. In contrast, the sediment environment was more resilient to both agricultural disturbances and abiotic factors. This study expands our understanding of when and where different stages of N and P cycling occurs in agriculturally impacted watersheds, and identifies both seasons and regions to target with nutrient mitigation strategies.

The relationship between subjective sleep disturbance and attenuated psychotic symptoms after accounting for anxiety and depressive symptoms.

BACKGROUND AND HYPOTHESES: Sleep disturbances are increasingly recognized as cooccurring with psychotic symptoms. The potential importance of this relationship is complicated when considering the effects of anxiety and depressive symptoms which commonly present in early-stage illness states. This study aimed to investigate the relationship between self-reported sleep disturbance on the development of attenuated psychotic symptoms (APS) cross-sectionally and longitudinally while adjusting for roles of anxiety and depressive symptoms. DESIGN: Eight-hundred and two help-seeking young people aged 12 to 25 years who engaged with our Australian early intervention services were included in the study (the "Transitions" cohort). Cross sectional mediation and cross-lagged longitudinal (12-month) mediation models were developed with outcomes being different APS domains. RESULTS: Only baseline excessive daytime sleepiness predicted later APS when accounting for previous APS, anxiety and depressive symptomatology. Cross sectionally, self-reported sleep disturbance showed both direct and indirect predictive relationships with all APS domains. Partial mediation through anxiety and depression was shown for unusual thought content, perceptual abnormalities, and disorganised speech, while full mediation through depression was shown for non-bizarre ideas. CONCLUSIONS: The specificity of the relationship between self-reported sleep disturbance on APS highlights the potential for different roles in mechanistic models of psychotic symptom expression. This further indicates the need for further experimental research to illuminate potential causal pathways. Future research should continue to use continuous, symptom level approaches across a range of timeframes to more accurately model the complex dynamics present in the sleep-psychosis relationship.

Predicting implicit and explicit exercise identity from descriptive social norms regarding exercise.

OBJECTIVES: Exercise identity may promote exercise maintenance. However, less is known about factors that affect exercise identity. Whether descriptive social norms are potential intervention targets for identity development was evaluated. DESIGN: A cross-sectional design using data from the Attitudes, Identities, and Individual Differences (AIID) study was employed - with additional cases collected to increase sample size and power - to evaluate whether descriptive social norms regarding exercise are related to implicit and explicit exercise identities. MAIN OUTCOME MEASURES: Participants completed measures of proximal and distal descriptive social norms regarding exercise, explicit and implicit exercise identity, physical activity behavior, and demographics. Multiple regression was used to assess whether social norms regarding exercise predict exercise identities. RESULTS: Only proximal descriptive social norms were significantly associated with explicit exercise identity, whereas neither proximal nor distal descriptive social norms were associated with implicit exercise identity. The slopes for explicit and implicit identity differed when predicted by distal (but not proximal) descriptive social norms. CONCLUSIONS: Proximal descriptive social norms may be associated with explicit exercise identity and may be a worthy intervention targeting alongside identity to influence change in exercise behavior. More research is needed to further understand these relationships.

Evaluating Objective Metrics of habit strength for taking medications.

Habit strength for taking medication is associated with medication adherence. However, habit strength is typically measured via self-reports, which have limitations. Objective sensors may provide advantages to self-reports. To evaluate whether habit-strength metrics derived from objective sensor data (MEMS® Caps; AARDEX Group) are associated with self-reported habit strength and adherence (objective and self-reported) and whether objective and self-reported habit strength are independently associated with adherence. Patients (N = 79) on oral medications for type 2 diabetes completed self-reports of habit strength and medication adherence and used MEMS® Caps to take their prescribed medication for one month. MEMS® Caps data were used to create five objective metrics of habit strength (e.g., individual-level variance in pill timing) and quantify medication adherence (% days correct dosing). Consistency in behavior from week to week (versus across each day) had the greatest association with self-reported habit strength (r(78) = 0.29, p = 0.01), self-reported adherence (r(78) = 0.32, p = 0.005), and objective adherence (r(78) = 0.61, p < 0.001). Objective and self-reported habit strength were independently associated with adherence. Weekly pill-timing consistency may be more useful than daily pill-timing consistency for predicting adherence and understanding patients' medication-taking habits. Self-reports and objective metrics of habit strength may be measuring different constructs, warranting further research.

Ramifications of behavioural complexity for habit conceptualisation, promotion, and measurement.

Behavioural theories, predictions, and interventions should be relevant to complex, real-world health behaviours and conditions. Habit theory and habit formation interventions show promise for predicting and promoting, respectively, longer-term behaviour change and maintenance than has been attained with theories and interventions focused only on deliberative behavioural factors. However, the concept of habit has largely been treated as uniform across different types of behaviours. In this conceptual review, we contend that the definitional aspects of habit differ at a conceptual level for simple versus more complex behaviours, with ramifications for prediction, promotion, and measurement of habits. Specifically, habits are defined as direct context-response associations learned through repeatedly rewarded responding - but what is meant by 'response' and 'reward' depends upon the complexity of the behaviour. We review literature that suggests (1) responses in complex habits have separable and substitutable components (vs a single and static, unitary component) and (2) rewards for complex habits are necessarily continued and intrinsic (vs temporary and extrinsic, respectively). We discuss some empirical and theoretical questions raised by these issues around behavioural complexity and habit. Lastly, we outline the ramifications of these issues for habit measurement (habit strength and habit formation) via self-report and objective measures.

The missing middle: Asian employees' experience of workplace discrimination and pro-black allyship.

Asian employees occupy an intermediate status in the U.S. racial hierarchy between White and Black employees. Given this intermediate position, it is unclear whether and how Asian employees' own racial experience at work will affect their willingness to take action against racism toward other groups. In the current research, we examine how Asian employees' experiences of racism impact their propensity to combat racism against Black coworkers. Across four studies including a qualitative survey (Pilot), a time-lagged quantitative survey (Study 1), a preregistered experiment (Study 2), and a conceptual replication experiment (Study 3), we find that Asian employees who experience more racial discrimination at work feel more similar to Black individuals, which is subsequently associated with greater allyship toward Black coworkers. We find that this relationship is heightened among Asian employees who have stronger zero-sum beliefs (Study 1). Importantly, we further find that processes that lead to allyship among Asian employees differ among White employees (Studies 2-3): In contrast to Asian employees, White employees who perceive more anti-in-group workplace discrimination feel less similar to Black individuals, which is associated with diminished pro-Black allyship. By examining the poorly understood racial experiences of Asian employees, and uncovering mechanisms that propel Asian employees to engage in intergroup allyship, we provide a more complete picture of racism in the workplace. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Corrigendum: Evaluating behavior change factors over time for a simple vs. complex health behavior.

[This corrects the article DOI: 10.3389/fpsyg.2022.962150.].

Evaluating behavior change factors over time for a simple vs. complex health behavior.

Background: Researchers are working to identify dynamic factors involved in the shift from behavioral initiation to maintenance-factors which may depend on behavioral complexity. We test hypotheses regarding changes in factors involved in behavioral initiation and maintenance and their relationships to behavioral frequency over time, for a simple (taking a supplement) vs. complex (exercise) behavior. Methods: Data are secondary analyses from a larger RCT, in which young adult women, new to both behaviors, were randomly assigned to take daily calcium (N = 161) or to go for a daily, brisk walk (N = 171), for 4-weeks. Factors (intentions, self-efficacy, intrinsic motivation, self-identity, habit strength) were measured weekly. Multi-level modeling evaluated their change over time. Bivariate correlations and multiple regression determined the relationships between factors and the subsequent-week behavioral frequency (self-report and objective). Finding: Results were partly in-line with expectations, in that individuals' intentions and self-efficacy predicted initial behavioral engagement for both behaviors, and habit strength increased for both behaviors, becoming a significant predictor of behavioral frequency in later weeks of the study in some analyses. However, results depended on whether the outcome was self-reported or objectively measured and whether analyses were bivariate or multivariate (regression). Discussion: The factors theorized to play a role in behavioral maintenance (intrinsic motivation, self-identity, and habit strength) started to develop, but only habit strength predicted behavioral frequency by study-end, for both behaviors. Differences in initiation and maintenance between behaviors of differing complexity may not be as stark as theorized, but longer follow-up times are required to evaluate maintenance factors.

The utility of the integrated behavior change model as an extension of the theory of planned behavior.

Introduction: There are several widely used theories of health behavior change, which mostly utilize the social cognitive approach. These theories tend to posit that intention is a direct predictor of behavior, do not include automatic influences on behavior, and propose a one-size-fits-all theory for both initiators and maintainers. However, the intention-behavior gap is a well-observed phenomenon, researchers have highlighted that both automatic and reflective factors promote behavioral engagement, and predictors of behavior have been shown to differ between initiators and maintainers-three issues that necessitate theory advancement. To that end, the present research compares the utility of the Integrated Behavior Change Model (IBCM) - a social cognitive model that includes automatic factors involved in behavioral engagement and a moderator of the intention-behavior gap - to its theoretical predecessor, the Theory of Planned Behavior (TPB). Further, the relevance of the IBCM factors for predicting exercise behavior is compared in initiators versus maintainers. Method: Participants were 494 US undergraduates. Participants reported on variables from the IBCM (and TPB) at baseline and reported on their exercise behavior in two surveys at seven- and 14-days post-baseline. Results: Findings supported the first hypothesis that the IBCM would be more relevant for initiators in comparison with maintainers, using structural equation modeling. Specifically, only the paths between intrinsic motivation and affective attitude, affective attitude and intention, and intention and behavior were reliably found for maintainers. For initiators, the aforementioned paths were also reliably supported and the additional following paths were also supported: intrinsic motivation and perceived behavioral control, perceived behavioral control and intention, and intention and action planning. However, results did not support the second hypothesis that the IBCM would predict significantly more variance in behavior than its theoretical predecessor, the TPB. Specifically, the addition of action planning, implicit attitude, implicit motivation, and the interaction between intention and action planning only predicted an additional 0.3% (p < 0:05) of the variance in exercise behavior above and beyond intention. Conclusion: Results highlight the continued need for theoretical refinement in terms of delineating mechanisms of initiation and maintenance and the need for further development in terms of improving upon current predictions of behavior engagement and change.

Contrasting constructs or continuum? Examining the dimensionality of body appreciation and body dissatisfaction.

Individuals experiencing body dissatisfaction have poorer health outcomes in part due to engaging in less physical activity. Body appreciation is protective of health behaviors and proposed to be conceptually different from body dissatisfaction. Two studies evaluated whether body appreciation and dissatisfaction represented two distinct dimensions, and whether body appreciation and dissatisfaction would interact in their effect on activity-related motivation and behavior. Study 1 (n = 313) was prospective and utilized a self-report measure of physical activity whereas Study 2 (n = 123) was prospective and used an objective measure. All hypotheses and analyses were pre-registered. A multiverse approach was taken to demonstrate the robustness of results. In exploratory factor analyses, body appreciation and dissatisfaction did not represent two distinct dimensions of body image as both loaded onto the same factor. This result was largely supported by latent profile analyses, which revealed that participants scored high, moderate, or low on both body satisfaction and appreciation. Additionally, body appreciation did not buffer the negative impact of body dissatisfaction on activity-related motivation and behavior. This study provides the first statistical evaluation of the theoretical proposition that body appreciation and dissatisfaction may be distinct constructs with distinct relationships to outcomes.

Prognosis and tumor biology of pancreatic cancer patients with isolated lung metastases: translational results from the German multicenter AIO-YMO-PAK-0515 study.

BACKGROUND: Pulmonary metastasis (M1-PUL) as first site of dissemination in pancreatic ductal adenocarcinoma (PDAC) is a rare event and may define a distinct biological subgroup. PATIENTS AND METHODS: Arbeitsgemeinschaft Internistische Onkologie-Young Medical Oncologists-Pankreas-0515 study (AIO-YMO-PAK-0515) was a retrospective German multicenter study investigating clinical and molecular characteristics of M1-PUL PDAC patients; 115 M1-PUL PDAC patients from 7 participating centers were included. Clinical characteristics and potential prognostic factors were defined within the M1-PUL cohort. Archival tumor samples were analyzed for Her2/neu, HNF1A and KRT81 expression. Additionally, messenger RNA (mRNA) expression analysis (using a 770-gene immune profiling panel) was carried out in the M1-PUL and in a control cohort (M1-ANY). RESULTS: Median overall survival in the entire M1-PUL cohort was 20 months; the most favorable prognosis (median survival: 28 months) was observed in the subgroup of 66 PDAC patients with metachronous lung metastases after previous curative-intent surgery. The number of metastatic lesions, uni- or bilateral lung involvement as well as metastasectomy were identified as potential prognostic factors. Her2/neu expression and PDAC subtyping (by HNF1A and KRT81) did not differ between the M1-PUL and the M1-ANY cohort. mRNA expression analysis revealed significant differentially expressed genes between both cohorts: CD63 and LAMP1 were among the top 20 differentially expressed genes and were identified as potential mediators of organotropism and favorable survival outcome of M1-PUL patients. CONCLUSION: M1-PUL represents a clinically favorable cohort in PDAC patients. Site of relapse might already be predetermined at the time of surgery and could potentially be predicted by gene expression profiling.

What counts as discrimination? How principles of merit shape fairness of demographic decisions.

Demographic attributes (e.g., age, disability, race) frequently affect people's decisions. We provide a novel perspective as to why such discrimination persists: Meritocratic principles lead people to perceive some demographic attributes as fair to use, rather than as discriminatory. Specifically, we theorize that meritocracy requires that controllable and relevant inputs determine outcomes; as a result, perceived controllability and relevance affect the degree to which demographic attributes are perceived as fair to use. Moreover, we suggest perceived relevance outweighs controllability, such that even uncontrollable attributes can be perceived as fair criteria if perceived to be outcome relevant. In two qualitative studies, we probed how people think about demographic attributes used in selection (Studies 1a-b). We find that people refer to controllability and relevance dimensions to justify their perceptions. Further, people largely associate uncontrollable, irrelevant attributes with discrimination (race, sex), neglecting attributes they perceive as controllable and/or relevant (disability, caregiving status). Next, three surveys (Studies 2a-c) support our theorizing that perceived relevance impacts fairness perceptions more strongly than perceived controllability. In three experiments (Studies 3a-c), we provide causal evidence that relevance and controllability shape perceived fairness, which in turn affects selection behaviors, including seeking information regarding demographic attributes during hiring. Finally, Study 4 demonstrates downstream consequences: Perceived controllability, relevance, and use of demographic attributes together impact employees' psychological safety and job satisfaction. Overall, we find that principles of merit lead people to believe that even some legally protected demographic attributes are fair to use, allowing discrimination to persist. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Vulnerable migrants' access to healthcare in the early stages of the COVID-19 pandemic in the UK.

OBJECTIVES: To understand the living conditions, changes in the service user profile, and needs of vulnerable migrants trying to access healthcare in the early stages of the COVID-19 pandemic. STUDY DESIGN: Mixed methods study; using quantitative questionnaire data collected from migrant service users of Doctors of the World UK (DOTW UK) with qualitative data from free-text notes. METHODS: DOTW UK provides drop-in clinics to vulnerable migrants. Consultations switched to remote during the UK's first lockdown. We compared patient profile, well-being, healthcare access and reason for consultations of individuals attending the virtual clinic between March and September 2020 to those of the prepandemic periods between 2011 and 2018. RESULTS: During the pandemic, consultations dropped to under half of the prepandemic numbers, with the shift to remote consultations attracting more users outside of London. DOTW UK's user base changed to include a greater proportion of asylum seekers, younger adults (18-34) and individuals reporting good health. Socio-economic conditions and housing stability deteriorated for the majority of users. Those in the greatest need of healthcare appeared to be less able to access remote services. General practitioner (GP) registration remained the most common reason for contacting the virtual clinic with a lack of knowledge of the healthcare system being the main barrier to access. CONCLUSION: The shift to virtual consultations may have exacerbated existing inequalities in healthcare access for vulnerable migrants. Given that many clinical services continue to operate remotely, it is important to consider the impact such actions have on vulnerable migrants and find ways to support access.

Has improved treatment contributed to the declining rate of transition to psychosis in ultra-high-risk cohorts?

BACKGROUND: The factors contributing to declining psychotic disorder transition rates in ultra-high-risk populations remain unclear. We examined the contribution of longitudinal changes in standard clinical treatment ('treatment as usual') to this decline. METHOD: An audit was conducted on 105 clinical files of patients who received standard care at a specialised ultra-high-risk service. The session notes of these files were quantified, allowing examination of treatment quantity, targets, psychotherapy, and medication. Differences in these aspects across patients' year of clinic entry were assessed. Variables with significant differences across years were examined using cox regression to assess their contribution to psychosis transition rates. RESULTS: Findings were that, as a function of patients' year of clinic entry, there were increases in: patients' number of sessions, cognitive behavioural therapy (CBT), problem and solving therapy. There was a relationship between baseline year cohort and psychosis transition rate, with lower rates observed in more recent cohorts. When changes in treatment between cohorts were adjusted for, the relationship between baseline year cohort and transition rate disappeared. The relationship between baseline year and transition rate was attenuated most by increases in CBT. CONCLUSION: Changes in standard treatment, particularly increases in CBT, may have contributed to the decline in psychosis risk observed in recent ultra-high-risk cohorts, although these variables do not fully explain this trend. Implications for clinical practice, prediction and intervention research are discussed. Future ultra-high-risk research should investigate the impact of other treatment factors, such as therapeutic alliance.

Why benefiting from discrimination is less recognized as discrimination.

Discrimination continues to plague society, creating stark inequities between groups. While existing work has considered the role of prejudice in perpetuating discrimination, we draw on emerging research on privilege and inequity frames to offer an overlooked, complementary explanation: Objectively discriminatory decisions that are described as favoring, compared with disfavoring, are less likely to be recognized as discrimination. We further theorize this is because favoring decisions are perceived to be motivated by positive intentions. We find support for our hypotheses across eight studies. First, using both qualitative (Studies 1a-b) and experimental approaches (Studies 2-7), across a range of discrimination contexts including race, sex, nationality, and age, we find that inequity frames affect perceptions of discrimination. Further, we find that even human resource employees are less likely to recognize discrimination when described as favoring (Study 3), in turn affecting their reporting behaviors: They are less likely to report potentially discriminatory decisions for review. Next, sampling language from U.S. Supreme Court cases, we find that people support litigation less when discrimination uses a favoring frame, versus disfavoring frame (Study 4). Then, we find that this pattern is driven by inequity frames shaping perceived intentions, rather than perceived harm (Studies 5-6). Finally, we find some evidence that inequity frames regarding a discriminatory decision committed by an organization may affect candidates' job pursuit behaviors (Study 7). This work contributes to a nascent perspective that advantaging mechanisms are critical for creating group inequity: given individuals are less likely to recognize favoritism as discriminatory, favoritism may especially contribute to the persistence of inequity. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Symptom attribution to a medically unexplained syndrome is associated with greater perceived severity and bothersomeness of symptoms in US military veterans.

OBJECTIVE: Medically unexplained symptoms (MUS) are prevalent among veteran and non-veteran populations. Current biopsychosocial theory implicates a multitude of factors in MUS development and perpetuation. The current study tests whether physical symptom attribution to MUS is associated with perceived symptom severity and bothersomeness and thereby might function to perpetuate MUS, as suggested by existing theory. DESIGN AND MAIN OUTCOME MEASURES: Military combat veterans (n = 243) answered postal-mail questions about their physical symptoms, severity of experienced symptoms, and attributions of these symptoms to MUS (e.g. Gulf War Illness) versus non-MUS conditions. RESULTS: Independent t-tests showed support for the first hypothesis-that those who experience the symptom and attribute it to MUS will perceive it to be more severe and bothersome than those who experience the symptom but do not attribute it to MUS. Paired-sample t-tests showed support for the second hypothesis-that experienced symptoms attributed to MUS by an individual will be perceived as more severe and bothersome than experienced symptoms the individual does not attribute to MUS. CONCLUSIONS: Results highlight a potential role of symptom attribution in MUS perpetuation, through greater perceived severity and bothersomeness of MUS-attributed symptoms. Possible intervention targets may include behavior ramifications, such as coping strategies; more research is needed.