Mixture modeling is a widely applied data analysis technique used to identify unobserved heterogeneity in a population. Despite mixture models' usefulness in practice, one unresolved issue in the application of mixture models is that there is not one commonly accepted statistical indicator for deciding on the number of classes in a study population. This article presents the results of a simulation study that examines the performance of likelihood-based tests and the traditionally used Information Criterion (ICs) used for determining the number of classes in mixture modeling. We look at the performance of these tests and indexes for 3 types of mixture models: latent class analysis (LCA), a factor mixture model (FMA), and a growth mixture models (GMM). We evaluate the ability of the tests and indexes to correctly identify the number of classes at three different sample sizes (n = 200, 500, 1,000). Whereas the Bayesian Information Criterion performed the best of the ICs, the bootstrap likelihood ratio test ...

Deciding on the Number of Classes in Latent Class Analysis and Growth Mixture Modeling: A Monte Carlo Simulation Study

Introduction 1. Woman's Place in Man's Life Cycle 2. Images of Relationship 3. Concepts of Self and Morality 4. Crisis and Transition 5. Women's Rights and Women's Judgment 6. Visions of Maturity References Index of Study Participants General Index

In a Different Voice. Psychological Theory and Women’s Development. Cambridge, MA (Harvard University Press) 1982.

Well-being : the foundations of hedonic psychology

This review presents a practical summary of the missing data literature, including a sketch of missing data theory and descriptions of normalmodel multiple imputation (MI) and maximum likelihood methods. Practical missing data analysis issues are discussed, most notably the inclusion of auxiliary variables for improving power and reducing bias. Solutions are given for missing data challenges such as handling longitudinal, categorical, and clustered data with normal-model MI; including interactions in the missing data model; and handling large numbers of variables. The discussion of attrition and nonignorable missingness emphasizes the need for longitudinal diagnostics and for reducing the uncertainty about the missing data mechanism under attrition. Strategies suggested for reducing attrition bias include using auxiliary variables, collecting follow-up data on a sample of those initially missing, and collecting data on intent to drop out. Suggestions are given for moving forward with research on missing data and attrition.

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Missing data analysis: making it work in the real world.

The adolescent brain and age-related behavioral manifestations

Data were collected on the point and lifetime prevalences, 1-year incidence, and comorbidity of depression with other disorders (Diagnostic and Statistical Manual of Mental Disorders [3rd ed., rev.]) in a randomly selected sample (n = 1,710) of high school students at point of entry and at 1-year follow-up (n = 1,508). The Schedule for Affective Disorders and Schizophrenia for School-Age Children was used to collect diagnostic information; 9.6% met criteria for a current disorder, more than 33% had experienced a disorder over their lifetimes, and 31.7% of the latter had experienced a second disorder. High relapse rates were found for all disorders, especially for unipolar depression (18.4%) and substance use (15.0%). Female subjects had significantly higher rates at all age levels for unipolar depression, anxiety disorders, eating disorders, and adjustment disorders; male subjects had higher rates of disruptive behavior disorders.

Adolescent psychopathology: I. Prevalence and incidence of depression and other DSM-III-R disorders in high school students.

This study investigates the role of certain psychosocial variables--sex, age, body image/self-esteem, self-consciousness, stressful life events, and the degree to which an individual identifies with the cultural stereotype of masculinity--as correlates and antecedents to depression in adolescents and explores possible intraindividual mediators of the stress-depression relationship in adolescents. A battery of self-report measures was administered to public high school students in Grades 9-12 in their classrooms at two different times 1 month apart. Female adolescents reported more depressive symptoms, self-consciousness, stressful recent events, feminine attributes, and negative body image and self-esteem; no age effects were obtained. Results suggest a model of adolescent depression in which body/self-esteem and stressful recent events are significant contributors.

http://psycnet.apa.org/journals/abn/99/1/55.pdf

Sex differences and adolescent depression.

Cognitive-behavioral treatment for depressed adolescents*

Operating characteristics of the Center for Epidemiologic Studies Depression Scale (CES-D) were examined by using data from 4 samples of students in Grades 9-12. Although it appears that the CES-D scale may be appropriate for use with adolescents, the issues of stability of scores over time, appropriate cutoff scores, and usefulness in detecting cases of clinical depression remain unresolved

Assessment of Depression in Adolescents Using the Center for Epidemiologic Studies Depression Scale

In a prospective study of adolescent depression, adolescents (N = 1,508) were assessed at Time 1 and after 1 year (Time 2) on psychosocial variables hypothesized to be associated with depression. Most psychosocial variables were associated with current (n = 45) depression. Formerly depressed adolescents (n = 217) continued to differ from never depressed controls on many of the psychosocial variables. Many of the depression-related measures also acted as risk factors for future depression (n = 112), especially past depression, current other mental disorders, past suicide attempt, internalizing behavior problems, and physical symptoms. Young women were more likely to be, to become, and to have been depressed. Controlling for the psychosocial variables eliminated the gender difference for current and future but not for past depression.

Hyman Hops

Papers

Adolescent psychopathology: I. Prevalence and incidence of depression and other DSM-III-R disorders in high school students.

Sex differences and adolescent depression.

Cognitive-behavioral treatment for depressed adolescents*

Assessment of Depression in Adolescents Using the Center for Epidemiologic Studies Depression Scale

Adolescent Psychopathology: II. Psychosocial Risk Factors for Depression