What is the actual relationship between neutrophil extracellular traps and COVID-19 severity? A longitudinal study.

BACKGROUND: Neutrophil extracellular traps (NETs) have repeatedly been related to COVID-19 severity and mortality. However, there is no consensus on their quantification, and there are scarce data on their evolution during the disease. We studied circulating NET markers in patients with COVID-19 throughout their hospitalization. METHODS: We prospectively included 93 patients (201 blood samples), evaluating the disease severity in 3 evolutionary phases (viral, early, and late inflammation). Of these, 72 had 180 samples in various phases. We also evaluated 55 controls with similar age, sex and comorbidities. We measured 4 NET markers in serum: cfDNA, CitH3, and MPO-DNA and NE-DNA complexes; as well as neutrophil-related cytokines IL-8 and G-CSF. RESULTS: The COVID-19 group had higher CitH3 (28.29 vs 20.29 pg/mL, p = 0.022), and cfDNA, MPO-DNA, and NE-DNA (7.87 vs 2.56 ng/mL; 0.80 vs 0.52 and 1.04 vs 0.72, respectively, p < 0.001 for all) than the controls throughout hospitalisation. cfDNA was the only NET marker clearly related to severity, and it remained higher in non-survivors during the 3 phases. Only cfDNA was an independent risk factor for mortality and need for intensive care. Neutrophil count, IL-8, and G-CSF were significantly related to severity. MPO-DNA and NE-DNA showed significant correlations (r: 0.483, p < 0.001), including all 3 phases and across all severity grades, and they only remained significantly higher on days 10-16 of evolution in those who died. Correlations among the other NET markers were lower than expected. CONCLUSIONS: The circulating biomarkers of NETs were present in patients with COVID-19 throughout hospitalization. cfDNA was associated with severity and mortality, but the three other markers showed little or no association with these outcomes. Neutrophil activity and neutrophil count were also associated with severity. MPO-DNA and NE-DNA better reflected NET formation. cfDNA appeared to be more associated with overall tissue damage; previous widespread use of this marker could have overestimated the relationship between NETs and severity. Currently, there are limitations to accurate NET markers measurement that make it difficult to assess its true role in COVID-19 pathogenesis.

IL-6 and cfDNA monitoring throughout COVID-19 hospitalization are accurate markers of its outcomes.

BACKGROUND: Severe COVID-19 entails a dysregulated immune response, most likely inflammation related to a lack of virus control. A better understanding of immune toxicity, immunosuppression balance, and COVID-19 assessments could help determine whether different clinical presentations are driven by specific types of immune responses. The progression of the immune response and tissular damage could predict outcomes and may help in the management of patients. METHODS: We collected 201 serum samples from 93 hospitalised patients classified as moderately, severely, and critically ill. We differentiated the viral, early inflammatory, and late inflammatory phases and included 72 patients with 180 samples in separate stages for longitudinal study and 55 controls. We studied selected cytokines, P-selectin, and the tissue damage markers lactate dehydrogenase (LDH) and cell-free DNA (cfDNA). RESULTS: TNF-α, IL-6, IL-8, and G-CSF were associated with severity and mortality, but only IL-6 increased since admission in the critical patients and non-survivors, correlating with damage markers. The lack of a significant decrease in IL-6 levels in the critical patients and non-survivors in the early inflammatory phase (a decreased presence in the other patients) suggests that these patients did not achieve viral control on days 10-16. For all patients, lactate dehydrogenase and cfDNA levels increased with severity, and cfDNA levels increased in the non-survivors from the first sample (p = 0.002) to the late inflammatory phase (p = 0.031). In the multivariate study, cfDNA was an independent risk factor for mortality and ICU admission. CONCLUSIONS: The distinct progression of IL-6 levels in the course of the disease, especially on days 10-16, was a good marker of progression to critical status and mortality and could guide the start of IL-6 blockade. cfDNA was an accurate marker of severity and mortality from admission and throughout COVID-19 progression.

Frustrated interpersonal needs as a motivational moderator in the integrated motivational-volitional model.

A theoretical assumption of the integrated motivational-volitional (IMV) model positions perceived burdensomeness (PB) and thwarted belongingness (TB) as moderators on the entrapment-suicidal ideation/intention relationship. The present study analyzed the expected combined effects of PB × TB on the relationship between entrapment and suicidal ideation/intention. Data were collected using an online questionnaire (N = 644) selected by sex, age, and education level. The PB × TB × Entrapment interaction was statistically significant, according to a moderating effect. A high degree of frustration of interpersonal needs enhances the entrapment-suicidal ideation/intention relationship.

Adaptation to the Spanish population of the Substance Use Risk Profile Scale (SURPS) and psychometric properties. / Adaptación a la población española de la Escala de Perfil de Riesgo de Consumo de Drogas (EPRCD) y estudio de sus propiedades psicométricas.

The identification of different personality risk profiles for substance misuse is useful in preventing substance-related problems. This study aims to test the psychometric properties of a new version of the Substance Use Risk Profile Scale (SURPS) for Spanish college students. Cross-sectional study with 455 undergraduate students from four Spanish universities. A new version of the SURPS, adapted to the Spanish population, was administered with the Beck Hopelessness Scale, the UPPS-P Impulsive Behavior Scale, the State-Trait Anxiety Inventory (STAI) and the Alcohol Use Disorders Identification Test (AUDIT). Internal consistency reliability ranged between 0.652 and 0.806 for the four SURPS subscales, while reliability estimated by split-half coefficients varied from 0.686 to 0.829. The estimated test-retest reliability ranged between 0.733 and 0.868. The expected four-factor structure of the original scale was replicated. As evidence of convergent validity, we found that the SURPS subscales were significantly associated with other conceptually-relevant personality scales and significantly associated with alcohol use measures in theoretically-expected ways. This SURPS version may be a useful instrument for measuring personality traits related to vulnerability to substance use and misuse when targeting personality with preventive interventions.

La identificación de diferentes perfiles de personalidad de riesgo para el consumo problemático de drogas es útil para prevenir problemas relacionados con las drogas. Este estudio tiene como objetivo analizar las propiedades psicométricas de una nueva versión de la Substance Use Risk Profile Scale (SURPS) en estudiantes universitarios españoles. Estudio de diseño transversal en el que participaron 455 estudiantes de cuatro universidades españolas. La nueva versión de la SURPS adaptada a la población española fue administrada junto a la Escala de Desesperanza de Beck, la UPPS-P, el inventario de ansiedad-estado (STAI) y el test AUDIT. La consistencia interna de las cuatro subescalas de la SURPS osciló entre 0,652 y 0,806. Los coeficientes de fiabilidad por el procedimiento de dos mitades oscilaron entre 0,686 y 0,829. La estimación test-retest osciló entre 0,733 y 0,868. Se replicó la estructura factorial esperada de cuatro dimensiones. Como evidencias de validez convergente, se encontró que las subescalas de la SURPS se relacionaron significativamente con las medidas teóricamente esperadas de otras escalas de personalidad y con el consumo de alcohol. Esta versión de la SURPS constituye un instrumento útil para la medición de rasgos de personalidad relacionados con la vulnerabilidad al consumo de drogas y sus problemas relacionados, pudiendo ser utilizada para estrategias de prevención del consumo de drogas.

Is it advisable to include negative attributes to assess the stereotype content? Yes, but only in the morality dimension.

Competence, morality and sociability dimensions have shown to be essential to measure stereotypes. Theoretically, the attributes associated with the negative pole of morality are more reliable and have shown to have higher evaluative weight. However, the current research usually employs only positive attributes to measure each dimension. Since the advantages of the inclusion of negative morality are clear it would be interesting to know about the effects of the inclusion of such type of attributes (i.e., it is good or bad for the measurement). The purpose of this study is to examine if the addition of negative items makes possible to improve the stereotype content measures. This study compares the differences between scales with various compositions of positive and negative items of stereotypes to predict three related variables: anger, fear and a semantic differential of evaluation. The study was carried out with a sample of 550 Spaniards. The data found highlights the importance of using attributes of the negative pole of morality in studying stereotypes. Their use was able to explain the intergroup emotional responses and the semantic differential more efficiently.

Harm reduction behaviors among young polysubstance users at raves.

BACKGROUND: Raves may be considered recreational settings in which drug use and health risks related to polydrug use are higher than in others. Harm reduction behaviors implemented by ravers are of particular relevance in reducing such risks. This study analyzes harm reduction behaviors and their relationship to raver polysubstance use patterns. METHODS: Cross-sectional study of 248 ravers recruited at underground raves in Andalusia (Spain). A questionnaire was developed to collect information about their sociodemographics, drug use, and harm reduction behaviors. RESULTS: The results show that ravers employ harm reduction behaviors for minimizing drug-related harm. Nevertheless, only a small minority of the participants frequently employed harm reduction behavior for polysubstance use as well. Ravers identified as high polysubstance users protected themselves significantly less than those identified as low polysubstance users. CONCLUSIONS: This study provides empirical information that may be useful for harm reduction intervention in a hidden and hard-to-reach population like rave attendees. The results point to the need to inform and increase harm reduction behavior specifically aimed at polysubstance use by ravers, especially among more frequent users. Future directions for research are also suggested.

Structural model of acculturation attitudes and related psychosocial variables: empirical evidence in native Spaniards.

This work falls within the framework of the study of acculturation processes of natives and immigrants. Its goal is to test an explanatory multi-group model of natives' acculturation attitudes as a function of diverse psychosocial variables: Prejudice and natives' appraisal of their own culture (in a direct way) and inter-group contact and perceived inter-group similarity (in an indirect way). Participants were 499 Spaniards surveyed for their attitude towards Romanian immigrants and 493 towards Ecuadorian immigrants. The indicators used took into account three socio-cultural spheres: peripheral, intermediate and central areas. This multi-group model shows an adequate fit to the data.

[Raves and drug use from an epidemiologic and psychosocial approach: a bibliographic systematic review]. / Raves y consumo de drogas desde una perspectiva epidemiológica y psicosocial: una revisión bibliográfica sistemática.

The high drug use that occurs at raves and the specific characteristics of these parties make them a high risk recreational context the health of participants. The aim of this paper is to establish a categorization of research on drug use and raves according to their objectives and main results. Knowledge and research needs identified as a result of this review are discussed. To this end, a systematic review of scientific literature through Medline, Psycinfo and Psicodoc was conducted. After applying the inclusion criteria, 36 papers were obtained, classified into six categories. The results show that 23 studies aim psychosocial profile analysis, and the prevalence and patterns of drug use. Nine studies focus on risks related to drug use, and nine in the drug effects. Given the high risk associated with raves and the scarcity of empirical studies identified, the need to develop further empirical studies is addressed. There is still insufficient evidence to guide intervention strategies to prevent risks and harms among ravers. There is also a need to explore: polydrug use, harm reduction strategies, positive effects and motivations.

Scale of psychological pain: Spanish adaptation of the Psychache Scale in young adults.

INTRODUCTION: Psychological pain is understood as an intolerable and disturbing mental state characterized by an internal experience of negative emotions. This study was aimed at making a Spanish adaptation of the Psychache Scale by Holden and colleagues in a sample of young adults. MATERIAL AND METHODS: The scale evaluates psychological pain as a subjective experience. It is composed of 13 items with a Likert-type response format. Following the guidelines of the International Tests Commission for the adaptation of the test, we obtained a version conceptually and linguistically equivalent to the original scale. Through an online questionnaire, participants completed the psychological pain scale along with other scales to measure depression (BDI-II), hopelessness (Beck's scale of hopelessness) and suicide risk (Plutchik suicide risk scale). The participants were 234 people (94 men, 137 women and three people who identified as a different sex) from 18 to 35 years old. RESULTS: The EFA showed a one-factor solution, and the FCA revealed adequate indexes of adjustment to the unifactorial model. It also showed good reliability of the test scores. The evidence of validity of the scale in relation to the other variables showed high, positive and statistically significant correlations with depression, hopelessness, suicidal ideation and suicidal risk. CONCLUSION: In summary, this Spanish adaptation of the Psychache Scale could contribute to improving the evaluation of both the patient with suicide risk and the effectiveness of psychological therapy, as well as suicidal behaviour prevention and intervention.

Harm Reduction Strategies among University Students Who Use Alcohol and Cannabis, and Related Psychological Variables: A Systematic Review.

This systematic review identifies the psychological variables associated with the use of harm reduction strategies (HRS) among university students who use alcohol or cannabis. The reviewed studies are categorized according to the psychological variables studied and the different analytic approaches used (direct effects, mediation, and moderation). Among the empirical peer-reviewed studies identified (n = 76), most (94.7%) were cross-sectional studies conducted in the US (90.8%) with samples of alcohol-using university students (86.8%). Five categories were identified: mental health, motives/expectancies, personality, social cognition, and self-efficacy. The most studied constructs were motives, anxiety and depression, impulsivity, and social norms. Most studies conducted mediation or moderation analyses including psychological variables, HRS and alcohol outcomes. Social, enhancement and coping motives, impulsivity, and social norms of alcohol use were associated with lower use of HRS, which, in turn, was associated with a higher number of alcohol/cannabis outcomes. The results of moderation studies consistently suggest that HRS use was more protective for students with poor mental health, high impulsivity, and low self-regulation. The synthesis of evidence provided in this review could be useful for guiding future research and informing the design of interventions aimed at promoting the use of HRS among university students who use alcohol and/or cannabis.

Prejudiced attitude measurement using the Rasch Rating Scale model.

There have been two basic approaches for the study of minority group prejudice against the majority: to adapt instruments from the majority group, and to use qualitative techniques by analyzing the content of the discourse of the groups involved. Neither of these procedures solves the problem of measuring intergroup attitudes of majorities and minorities in interaction. This study shows the result of a prejudice scale which was developed to measure the attitude of both the minority and majority groups. Prejudice is conceived as an attitude which requires the beliefs or opinions about the out-group, the emotions it elicits, and the behavior or intentional behavior toward it to be known for its evaluation. The innovation in this work is that the psychometric development of the scale was based on the item response theory, and more specifically, the rating scale model.

Experiential Avoidance in the Context of the Integrated Motivational-Volitional Model of Suicidal Behavior.

Background: According to the integrated motivational-volitional model of suicide, the perception of defeat and entrapment are the variables involved in the development of suicidal ideation. However, entrapment is not an inevitable consequence of feeling defeated. This transition is moderated by a set of variables relating to the ability to resolve the state of defeat. Aim: We aimed to study the potential moderating role of experiential avoidance in the relationship between defeat and entrapment in young adults. Method: A sample of 644 participants residing in Spain (51.2% female; Mage = 25.91, SDage = 5.14; range = 18-35 years old), selected by sex, age, and education level quotas, completed an online questionnaire consisting of: Defeat Scale; Entrapment Scale; and Acceptance and Action Questionnaire-II; and other sociodemographic variables. Results: Defeat and experiential avoidance had a statistically significant effect on entrapment. The interaction variable (defeat × experiential avoidance) was also statistically significant according to a moderating effect. Limitations: Due to the cross-sectional design, we could not establish causal associations between the variables. Conclusion: People who experience a high degree of defeat and experiential avoidance are more likely to progress to a state of entrapment, being more vulnerable to having suicidal ideation.

Profiles of patients with cocaine and alcohol use disorder based on cognitive domains and their relationship with relapse.

BACKGROUND: Relapse in drug use constitutes a research topic on addiction that is relevant for understanding both the addictive process and its clinical implications. The objective of this study was to explore if it is possible to identify patient profiles according to their performance on cognitive tasks whilst examining the relationship between such profiles and relapse. METHODS: The sample consisted of 222 patients with dependence on cocaine and / or alcohol, of which 86 % were men. Cognitive domains related to salience, decision- making, and emotional processing were measured. RESULTS: Latent class analysis revealed three patient profiles that differ in terms of performance on cognitive tasks. Two of these profiles are clearly differentiated in terms of their execution of the impulsive decision-making task. The third patient profile, unlike the latter two, is composed of patients with severe alterations in the three domains evaluated. Analysis revealed that patients in Profile 3 are those with the highest rates of relapse in cocaine (Profile 1 = 40.3 %; Profile 2 = 35.6 %; Profile 3 = 69.2 %; Chi2 = 9.169; p < .05) and cocaine and alcohol use (Profile 1 = 55.1 %; Profile 2 = 54.1 %; Profile 3 = 80 %; Chi2 = 6.698; p < .05). CONCLUSIONS: The results support the postulates of the I-RISA model. From a clinical perspective, these findings highlight the need for a comprehensive evaluation of the cognitive domains involved in addiction.

[In-group Bias Test adapted to the relative acculturation extended model: reliability and validity evidences]. / Test de favoritismo endogrupal interétnico adaptado al modelo ampliado de aculturación relativa: fiabilidad y evidencias de validez.

In-group favouritism has become a variable of enormous importance in the study of inter-ethnic relations. According to current approaches, it can be understood as a tendency among the members of one group to favour or value the behaviour, attitudes, preferences or perceptions of their own group over those of another group to which they do not belong. The aim of this work is to study the psychometric properties of a new test for measuring inter-ethnic in-group bias, in majority (native) and minority (immigrant) groups. The test is based on the acculturation areas of the Relative Acculturation Extended Model (RAEM). Participants were 992 Spaniards and 975 immigrants (500 Romanians and 475 Ecuadorians). The reliability estimate and validity evidence for these samples show that the psychometric properties of the In-group Bias Test are appropriate for use in multi-ethnic contexts, as it can be used in majority (native) and minority (Romanian and Ecuadorian immigrants) groups.

[Psychometric properties of the GHQ-28 in opiate-dependent patients]. / Propiedades psicométricas del GHQ-28 en pacientes con dependencia a opiáceos.

OBJECTIVE: To know the psychometric properties of the GHQ-28 when it is applied to a sample of opiate-dependent patients. METHOD: Participants were 138 opiate-dependent patients. Reliability was estimated by means of the Cronbach's alpha and Spearman-Brown coefficients. Confirmatory Factor Analysis was applied to check the four-factor structure proposed by Goldberg and Hillier. The sensitivity and specificity of the instrument for the detection of possible psychiatric cases were measured using ROC (Receiver Operating Characteristic) analysis, using as criterion the DSMIV diagnosis from the Mini International Neuropsychiatric Interview. RESULTS: Reliability estimation was adequate. Validity results could not confirm the four-factor structure of GHQ-28 proposed by Goldberg and Hillier. The sensitivity and specificity parameters show optimum values of 60.7 % and 73.7 %, respectively, 65.9 % of the participants being correctly classified. CONCLUSIONS: GHQ-28 shows adequate reliability and appropriate sensitivity and specificity parameters when it is applied to opiate-dependent patients. However, the original factorial structure could not be confirmed. Given these results and those from other validity studies in which the relationships with Severity of Dependence, Physical Health and Health-Related Quality of Life were shown, the GHQ-28 can be considered a useful instrument for screening in clinical practice.

Patterns of Simultaneous Polysubstance Use among Partygoers: Correlates and Differences in Adverse Acute Effects Experienced.

This study identifies patterns of simultaneous polysubstance use (SPU) in partygoers, their associated characteristics, and their differences in terms of acute effects experienced. We used a web-based survey with 1345 partygoers who reported using at least one substance during the past year, collecting information on drug use and drug-related acute effects experienced at the last party attended. Latent class analysis identified three SPU profiles according to the use of nine substances: low polysubstance use (67.7%), moderate polysubstance use/hallucinogens (11.6%), and extensive polysubstance use/stimulants (20.7%). These profiles differed in their sociodemographic characteristics and were associated with different odds of experiencing adverse drug-related effects. Compared with participants with a profile of low polysubstance use or moderate polysubstance use/hallucinogens, those in the extensive polysubstance use/stimulants group were at higher odds of experiencing memory impairment, tachycardia, and bad mood after drug use. The only differences between the low polysubstance use and moderate polysubstance use/hallucinogens groups were in terms of hangover and headache experiences, which were less likely in the latter group (who consume less alcohol). Knowledge regarding the acute adverse drug-related effects experienced by partygoers who use multiple drugs can help to develop interventions for reducing drug-related risks in this population.

Spanish Adaptation of the Protective Behavioral Strategies Scale-20 (S-PBSS-20) and Evaluation of its Psychometric Properties in University Students.

BACKGROUND: Protective behavioral strategies (PBS) have shown utility in reducing alcohol-related negative consequences. The Protective Behavioral Strategies Scale (PBSS) is one of the most widely used and well-validated instruments for evaluating these strategies. However, a Spanish adaptation of this or any other measure of PBS is not available. We aimed to provide a Spanish version of PBSS-20 and examine its psychometric properties. METHOD: We recruited 538 undergraduate students from three Spanish universities (mean age = 21.2; females = 78%). Measures included the Spanish-PBSS-20 (S-PBSS-20), Young Adult Alcohol Consequences Questionnaire (YAACQ), Daily Drinking Questionnaire, and frequency of alcohol use, drunkenness, and binge drinking. RESULTS: Our results support the use of the original 3-factor structure of the PBSS-20. Internal consistency reliability ranged between 0.71-0.77, and evidence of validity was provided according to the expected relationships with other variables. Exploratory factor analyses provided evidence of convergent/discriminant validity of S-PBSS-20. CONCLUSIONS: The results suggest that PBSS-20 is a useful instrument for assessing protective behavioral strategies in alcohol users. The S-PBSS-20 could be useful for research on alcohol-related protective behavioral strategies and consequences, and could also inform the design of educational interventions for promoting the use of protective strategies and reducing alcohol-related negative consequences.

Suicidal Ideation Profiles in Patients with Fibromyalgia Using Transdiagnostic Psychological and Fibromyalgia-Associated Variables.

Several studies have emphasized the heterogeneity of fibromyalgia patients. Furthermore, fibromyalgia patients are considered a high-risk suicide group. The ideation-to-action framework proposes a set of transdiagnostic psychological factors involved in the development of suicidal ideation. The present study aims to explore the existence of different subgroups according to their vulnerability to suicidal ideation through these transdiagnostic psychological variables and a set of variables typically associated with fibromyalgia. In this cross-sectional study, 151 fibromyalgia patients were assessed through the Revised Fibromyalgia Impact Questionnaire, Beck Depression Inventory-II, Plutchik Suicide Risk Scale, Interpersonal Needs Questionnaire, Defeat Scale, Entrapment Scale, Psychache Scale, and Beck Hopelessness Scale. A K-means cluster analysis identified two clusters, one (45.70%) according to a low vulnerability, and a second (54.30%) with a high vulnerability to suicidal ideation. These clusters showed statistically significant differences in suicidal ideation and suicide risk. However, no differences were observed in most socio-demographic variables. In conclusion, fibromyalgia patients who present a clinical condition characterized by a moderate-high degree of physical dysfunction, overall disease impact and intensity of fibromyalgia-associated symptoms, along with a high degree of perceived burdensomeness, thwarted belongingness, defeat, entrapment, psychological pain and hopelessness, form a homogeneous group at high risk for suicidal ideation.

Scale of psychological pain: Spanish adaptation of the Psychache Scale in young adults. / Escala de dolor psicológico: adaptación de la Psychache Scale al español en jóvenes adultos.

INTRODUCTION: Psychological pain is understood as an intolerable and disturbing mental state characterized by an internal experience of negative emotions. This study was aimed at making a Spanish adaptation of the Psychache Scale by Holden and colleagues in a sample of young adults. MATERIAL AND METHODS: The scale evaluates psychological pain as a subjective experience. It is composed of 13 items with a Likert-type response format. Following the guidelines of the International Tests Commission for the adaptation of the test, we obtained a version conceptually and linguistically equivalent to the original scale. Through an online questionnaire, participants completed the psychological pain scale along with other scales to measure depression (BDI-II), hopelessness (Beck's scale of hopelessness) and suicide risk (Plutchik suicide risk scale). The participants were 234 people (94 men, 137 women and three people who identified as a different sex) from 18 to 35 years old. RESULTS: The EFA showed a one-factor solution, and the FCA revealed adequate indexes of adjustment to the unifactorial model. It also showed good reliability of the test scores. The evidence of validity of the scale in relation to the other variables showed high, positive and statistically significant correlations with depression, hopelessness, suicidal ideation and suicidal risk. CONCLUSION: In summary, this Spanish adaptation of the Psychache Scale could contribute to improving the evaluation of both the patient with suicide risk and the effectiveness of psychological therapy, as well as suicidal behaviour prevention and intervention.

Motivational profiles and flow in physical education lessons.

The purpose of this study was to use cluster analysis to identify differences in goal orientation and motivational climate profiles among students in physical education classes as well as differences among the observed clusters on perceived flow experiences. 983 students of 14- to 15-yr.-olds (M = 14.8 yr., SD = 0.91) from a large Spanish metropolitan school district were participants and completed questionnaires assessing goal orientations, motivational climates, and perceived flow. Analysis showed three distinct clusters with 40.3% of the sample with a High Motivation cluster, 27.6% in a Low Motivation cluster, and 32.2% in a Mastery Motivation cluster. These three clusters differed significantly in ratings of perceived flow. Clusters also showed different composition by sex. Implications of these results with regard to instruction in physical education classes are discussed.