Psychopathology Textbooks Comparison: Comer vs. Barlow vs. Smerbeck (2026)

Dr. Smerbeck’s Psychological Disorders: The Science of Mental Health, v1.0 (FlatWorld) is built around the DSM-5-TR, which is the current APA standard for classifying mental disorders. Comer’s twelfth edition and Barlow’s ninth retrofit the current diagnostic criteria into chapters originally written using the previous DSM-IV classifications. Each technically covers the same disorders. Currently, Smerbeck’s textbook is the only one that follows the DSM-5-TR’s organizational structure from the first chapter to the last.

Macmillan sells a term of Achieve access to Comer's twelfth edition for $114.99 and Cengage sells a term of MindTap for Barlow's ninth for $127.00, while FlatWorld sells a full year of access to Smerbeck's first edition from $41.95 with the homework system included. Three numbers frame the comparison:

How Do Comer, Barlow, and Smerbeck Compare as Psychopathology Textbooks?

The Comer, Barlow, and Smerbeck textbooks all include the DSM-5-TR diagnostic criteria, so the table below compares what separates them: how each textbook is organized, what a student pays, and what the adoption includes. The full reasoning and sourcing for every row follow in the sections below.

What Changed in the DSM-5-TR, and Why Does It Matter for Your Textbook?

The DSM-5-TR is the current edition of the Diagnostic and Statistical Manual of Mental Disorders, published in 2022. The TR stands for text revision, which means the diagnostic categories from the DSM-5 stayed as they were while the surrounding text was updated.

The change that matters for psychopathology textbooks happened in 2013, when the DSM-5 reorganized the categories themselves. Three changes from that reorganization determine how a psychopathology textbook built on the DSM-5 is organized.

The DSM-5 Groups Disorders by Shared Features, Not by Age of Onset

The APA’s own fact sheet on the DSM-5 describes the change: disorders once addressed in a single “infancy, childhood and adolescence” chapter “are now integrated throughout the manual.” In its place the manual introduced Neurodevelopmental Disorders as, in the APA’s words, “a new heading that includes autism spectrum disorders, intellectual developmental disorder, attention-deficit/hyperactivity disorder and tic disorders.”

The DSM-5 Separates Obsessive-Compulsive Disorder from the Anxiety Disorders

The APA’s fact sheet on the DSM-5 gives the reason the manual separated obsessive-compulsive disorder from the anxiety disorders: “because recent studies have shown that obsessive-compulsive disorder involves distinct neurocircuits, it and several related disorders constitute their own chapter instead of being addressed in the chapter on anxiety disorders.”

What Disorders in the Same DSM-5 Category Share

Disorders in the same DSM-5 category tend to share symptoms, causes, and treatments, because the DSM-5 built its categories that way. That changes how a psychopathology course is taught, according to Dr. Alan Smerbeck, a licensed psychologist who teaches the course at Rochester Institute of Technology and is the author of FlatWorld’s Psychological Disorders. A student can learn what holds across the category and then the exceptions.

Dr. Smerbeck uses the DSM-IV’s childhood chapter to show why the DSM-5 stopped grouping disorders by age of onset. Under the DSM-IV arrangement, intellectual disability, dyslexia, and childhood anxiety disorders sat together because they tend to appear early in life. An anxiety disorder that begins in childhood has far more in common with the other anxiety disorders than with dyslexia, which is why the DSM-5 now places childhood-onset anxiety with the other anxiety disorders.

A chapter built on the DSM-IV arrangement gives a student no shared category to start from, so each disorder has to be learned on its own.

Do Comer and Barlow Conform to the DSM-5-TR?

Conforming to the DSM-5-TR can refer to either of two standards for a psychopathology textbook: including the current diagnostic criteria, or following the manual’s organizational structure. Comer’s twelfth edition and Barlow’s ninth include the criteria but keep chapters built on the DSM-IV organization.

Comer, Barlow, and Smerbeck All Include the DSM-5-TR Criteria

Macmillan’s own page for Comer’s twelfth edition states: “Fully updated based on DSM-5-TR, this is the most interactive edition yet.” That is accurate, and the same is true of Barlow’s ninth. When a professor asks whether a current edition is up to date on the manual, the diagnostic criteria are up to date.

The Table of Contents Shows Whether a Textbook Follows the DSM-5-TR’s Organization

A textbook can include every current criterion and still arrange its chapters using the DSM-IV’s structure. Dr. Smerbeck puts the distinction this way: Comer’s and Barlow’s texts do not use the DSM-IV, but they were organized around it and never fully reorganized when the DSM-5 changed the categories.

Two places in a psychopathology textbook’s table of contents show whether the book was reorganized around the DSM-5: the chapter for disorders first diagnosed in childhood, and the boundary of the anxiety chapter.

The Childhood Chapter in Comer, Barlow, and Smerbeck

Comer’s twelfth edition still gathers childhood disorders into one chapter, the arrangement the DSM-5 retired in 2013, while Barlow’s ninth and Smerbeck’s first edition use the APA’s replacement heading. In the DSM-5, the APA dissolved the single chapter of disorders first diagnosed in childhood and integrated those disorders throughout the manual. Barlow’s chapter 14 and Smerbeck’s chapter 10 are both titled Neurodevelopmental Disorders. Macmillan’s own published table of contents for Comer’s twelfth edition lists chapter 16 as “Disorders Common Among Children and Adolescents,” inside a part titled “Life-Span Problems.”

The Anxiety Boundary in Comer, Barlow, and Smerbeck

Comer’s twelfth edition and Barlow’s ninth both still include obsessive-compulsive disorder in their anxiety chapter, a pairing the DSM-5 split in 2013. Comer’s chapter 5 is “Anxiety, Obsessive-Compulsive, and Related Disorders.” Barlow’s chapter 5 is “Anxiety, Trauma- and Stressor-Related, and Obsessive-Compulsive and Related Disorders,” combining in one chapter what the manual separates into three. Smerbeck’s first edition gives the anxiety disorders chapter 5 on their own and opens chapter 6 with obsessive-compulsive and related disorders.

What the Table-of-Contents Comparison Covers and Leaves Out

The comparison of Comer, Barlow, and Smerbeck on DSM-5-TR organization rests on where each book’s chapter lines fall, in tables of contents that Macmillan, Cengage, and FlatWorld publish themselves. That evidence says nothing about the clarity of the writing in any of the three books or how often each is revised.

A table of contents does not show the content a revision added inside its chapters. Macmillan’s own page for Comer’s twelfth edition lists that content: coverage of the DSM-5-TR in chapter 4, updated diagnostic checklists throughout, and “new coverage of Prolonged Grief Disorder in Chapter 6, Disorders of Trauma and Stress based on the new DSM.” Macmillan also says that the twelfth edition moved its coverage of gender dysphoria from the sexual disorders chapter to the assessment chapter.

The point for a professor choosing a psychopathology textbook is narrow: the criteria your students read will be current in Comer, Barlow, or Smerbeck. The DSM-5-TR’s organizational structure can only be found in Smerbeck’s textbook.

Which to choose: Comer and Barlow are both strong fits if your curriculum is already built; FlatWorld is the stronger fit if you want the book's organization to match the DSM-5-TR's organization.

Why Did Comer and Barlow Change Their Titles for Their Current Editions?

Comer’s and Barlow’s current editions are published under new titles as the field of psychology replaces the previous title for the psychopathology course. The shift runs parallel to the DSM-5-TR, which updated the language around the diagnoses.

Macmillan renamed Comer’s textbook for its twelfth edition, and Cengage renamed Barlow’s for its ninth, replacing the name the eighth edition carried under the same three authors. Writing about a companion title in the same family, Macmillan states that the change moves past the stigma of the former course name and aligns with contemporary terminology to promote inclusive understanding of psychological health.

The American Psychological Association dropped the field’s former name from the title of its flagship journal, in a change announced in 2021 and effective with the 2022 volume. The APA’s published record gives the reasoning for the replacement term, psychopathology: the term “has been around for almost 2 centuries, and it has not yet accrued stigma. Perhaps this is because it labels the study of mental illness, rather than those who suffer from it.”

Use of the name psychopathology for the undergraduate course is still partial. Cengage’s own description of Barlow’s ninth edition uses both course names, and Macmillan sells a casebook under the former title.

Who Are Comer, Barlow, and Smerbeck?

The Comer, Barlow, and Smerbeck psychopathology textbooks have six authors among them, all psychology professors. Comer and Barlow are the two established names in the course. Smerbeck’s Psychological Disorders is a first edition, and its author is less familiar to most instructors, so his background gets the most room here. Each biography is drawn from the author’s own publisher.

Comer and Comer, Psychopathology: Science and Practice, 12e

Ronald J. Comer has been a member of Princeton University’s psychology department for 50 years and emeritus since 2016. He directed its Clinical Psychology Studies, chaired its Institutional Review Board, and has practiced as a clinical psychologist. Jonathan S. Comer is a professor of psychology at Florida International University, where he directs the Mental Health Interventions and Novel Therapeutics Program. A past president of the Society of Clinical Psychology, APA Division 12, he has written more than 250 scientific papers and chapters on child mental health, anxiety disorders, and the effects of trauma and disasters on children.

Barlow, Durand, and Hofmann, Psychopathology: An Integrative Approach to Mental Disorders, 9e

David H. Barlow is professor emeritus of psychology and psychiatry at Boston University, founder and director emeritus of the Center for Anxiety and Related Disorders, and a recipient of a Lifetime Achievement Award from the American Psychological Association. V. Mark Durand is a professor of psychology at the University of South Florida St. Petersburg and is known internationally for his work on autism spectrum disorders. Stefan G. Hofmann is the Alexander von Humboldt Professor for Translational Clinical Psychology at Philipps-University Marburg in Germany, a professor of psychology at Boston University, and editor of the journal Cognitive Therapy and Research.

Smerbeck, Psychological Disorders: The Science of Mental Health, v1.0

Alan M. Smerbeck (PhD, SUNY Buffalo) is an Associate Professor of Psychology at Rochester Institute of Technology and a New York State licensed psychologist. He teaches psychological disorders, developmental psychopathology, assessment, and human sexuality. Before RIT he was a postdoctoral research fellow at the Jacobs Neurological Institute in Buffalo, where he combined clinical work in neuropsychology with research on regression-based norms for neuropsychological tests and on controlled trials of drugs meant to improve cognition in multiple sclerosis patients.

Dr. Smerbeck’s research centers on psychological assessment, neuropsychology, autism spectrum disorder, and gender and sexuality, with attention to how psychological measures hold up in practice. His articles have appeared in Assessment, Multiple Sclerosis, Autism, The Clinical Neuropsychologist, and the Journal of Autism and Developmental Disorders. His work has contributed to the development and cross-cultural validation of cognitive and neuropsychological assessment tools, including international norms and alternate forms for clinical and research use. He has also written chapters and reviews for the Encyclopedia of Clinical Neuropsychology and the Mental Measurements Yearbook.

What Do Comer, Barlow, and Smerbeck Cost a Student?

Comer’s twelfth edition costs a student $114.99 for one term of Achieve, and Barlow’s ninth costs $127.00 for one term of MindTap. Smerbeck’s first edition costs $41.95 for a year of Basic access or $61.95 for a year of Standard. Each price was read at the seller’s own page: Macmillan’s on September 14, 2026, Cengage’s on September 16 and FlatWorld’s on September 21.

Macmillan sells Achieve for Comer’s twelfth edition as a subscription only. A student needs a course ID from the instructor to buy access. Print is priced separately, at $114.99 for the loose-leaf and $339.99 for the paperback, and the e-book runs $80.99 for six months or $120.99 to buy.

Beyond MindTap, Cengage sells Barlow’s ninth edition as a paperback at $257.95 and through Cengage Unlimited, at $169.99 for four months or $244.99 for twelve. Unlimited covers every Cengage course a student is taking. A student carrying three Cengage courses may well do better on the subscription than on three separate purchases.

FlatWorld sells a full year of access to Psychological Disorders: The Science of Mental Health, priced by package rather than by term. Basic is $41.95 and covers the textbook, FlatWorld Homework, integrated quizzes and flashcards, and SmartHelper, the AI study tool that answers only from the textbook’s own content. Standard is $61.95 and adds a downloadable copy-protected PDF, the audiobook, and the chapter podcasts. With the color print book they are $68.95 and $88.95. Every one of those four runs to the same date, one year from purchase.

A psychopathology course that runs two terms costs a student $114.99 twice on Achieve for Comer’s twelfth edition and $127.00 twice on MindTap for Barlow’s ninth. One year of FlatWorld access to Smerbeck’s first edition covers both terms.

The price gap between Achieve, MindTap, and FlatWorld comes from what each platform sells. On Achieve and MindTap, the courseware is the product and the textbook comes inside the platform. On FlatWorld, the textbook is the product and the courseware is included.

A publisher’s price can change within days: Cengage raised the prices on Barlow’s ninth edition between September 14 and September 16, 2026, with MindTap rising from $116.00 to $127.00 in forty-eight hours. Check the seller’s own page on the day you need the number, FlatWorld’s included.

Which to choose: Cengage Unlimited is a strong fit if your students carry several Cengage courses in one term; FlatWorld is the stronger fit if your students need one annual price with no subscription to manage.

Try the savings calculator to see what a section of your size pays under each model.

What Instructor Resources Come With Comer, Barlow, and Smerbeck?

The instructor packages for the Comer, Barlow, and Smerbeck textbooks each include an instructor’s manual, slides, sample syllabi, and a test bank. The packages differ in whether homework is included with student access and in how a custom edition gets built.

Comer’s twelfth edition and Barlow’s ninth both ship complete ancillary packages, built across twelve and nine editions respectively. Test banks, item files, slide decks, sample syllabi, instructor manuals, and the platform’s own assignment library are all in place.

FlatWorld’s instructor package is free with every adoption, and every supplement for Smerbeck’s first edition is available. The package includes the Instructor’s Manual, PowerPoint lecture notes, test generator, test bank files for LMS import, test item files, and sample syllabi. Dr. Smerbeck approved all of the supplements, including the homework and assessments.

FlatWorld’s student-facing tools for Smerbeck’s first edition are complete from day one. FlatWorld Homework is included with online access rather than sold as a platform, which is the practical difference behind the price gap with Achieve and MindTap. The same adoption includes LMS integration for Canvas, Blackboard, Moodle and Brightspace, an engagement dashboard that flags students falling behind, and SmartHelper. The Standard package adds the audiobook in 32 or more languages on request.

FlatWorld customization is either self-serve or built for the adopter. A FlatWorld adopter can reorder chapters, add original work, embed campus resources, and edit the text down to the individual word, immediately, and can combine content across titles. An adopter who would rather not make the changes can tell a local FlatWorld representative what the book should contain, and the representative handles the whole process.

Macmillan’s Custom Solutions page lists reordering chapters, adding original work, and embedding campus resources, and directs instructors to contact a specialist. Cengage’s custom-solutions pages list removing or replacing chapters, adding readings, cases, or exercises, and including your own material, with an enrollment minimum of 20 for books built in CengageCompose and 400 annually for custom digital solutions. Those pages are undated and may not be current. Contact Cengage for the terms on Barlow’s ninth. A FlatWorld adoption has no enrollment minimum, and the book can be customized down to the word.

Which to choose: Comer and Barlow are both strong fits if your slides, syllabi, and test items already come from an earlier edition of either book; FlatWorld is the stronger fit if you want homework, integrated quizzes, and SmartHelper included at $41.95 for Basic ($61.95 for Standard) and a custom book edited down to the word, by you or by a representative.

How Well Do Psychopathology Textbooks Accommodate Non-Majors?

A challenge instructors face when selecting a psychopathology textbook is accommodating non-majors. At least half the students in Dr. Smerbeck’s own sections are non-majors filling a general-education requirement.

A psychopathology class that mixes majors and non-majors poses a practical problem that a textbook either solves or ignores. A book written for students who already have the vocabulary and familiarity with research methods can set a faster pace. A book written for a mixed room has to build the vocabulary and the familiarity with research methods without becoming remedial for the majors.

Dr. Smerbeck is the author of Psychological Disorders, a textbook written for a class of majors and non-majors alike. The book assumes no shared background knowledge, so the vocabulary is built inside the chapters rather than taken for granted. A recurring feature, Psychology in the Community, shows how each chapter’s material applies outside the mental health fields, in law, policing, education, and medicine.

The illustrations in Psychological Disorders favor diagrams that show how ideas relate to one another over decorative photographs. Dr. Smerbeck made that choice because relationship diagrams support students who struggle with dense academic English.

What Student Activities Do the Comer, Barlow, and Smerbeck Textbooks Include?

Comer’s twelfth edition, Barlow’s ninth, and Smerbeck’s first edition each have a named student activity that emphasizes a different way of approaching diagnosis.

Comer’s twelfth edition introduced Clinical Choices, described by Macmillan as “new activities titled ‘Clinical Choices’ that allow students to experience how clinicians identify the symptoms of psychological disorders in virtual patients.”

Barlow’s ninth edition includes integrated case studies and a feature called Profiles in Psychopathology, which appear throughout the chapters.

Dr. Smerbeck’s Differential Diagnosis sections take the opposite approach from Comer’s Clinical Choices. Rather than practicing the diagnosis, the student watches a confident diagnosis fall apart, because the same symptoms can have many different causes.

The depressive disorders chapter of Psychological Disorders includes three Differential Diagnosis case stories. One person is sad because life is not going well, which is within the normal range. One cries several times a day, sleeps fourteen hours, and shows no interest in other people, and turns out to be a four-month-old baby. The third is in a depressive episode until the case reveals an earlier manic episode, which makes the diagnosis bipolar disorder rather than depression.

Dr. Smerbeck’s Differential Diagnosis feature responds to a problem he identifies in psychopathology courses: students start diagnosing themselves and everyone around them. The feature counters armchair and self-diagnosis by showing how quickly a student can move from a set of symptoms to the wrong diagnosis. The same caution extends to diagnosing a celebrity from a public persona.

Which to choose: Comer is a strong fit if you want students practicing diagnosis on virtual patients, and Barlow if you want integrated case studies and Profiles in Psychopathology. FlatWorld is the stronger fit if half your room is filling a requirement. A vignette opens every chapter, Differential Diagnosis case stories teach diagnostic caution, and Psychology in the Community shows where the material applies outside the mental health fields.

How Does Each Psychopathology Textbook Cover Pseudoscience?

Comer, Barlow, and Smerbeck differ in how much of each book goes to correcting misinformation about mental illness. Students arrive in a psychopathology course having already picked up ideas from social media, and some of those ideas are wrong.

Comer, Barlow, and Smerbeck all cover the theoretical models. Comer’s twelfth edition gives them chapter 3, “Models of Psychopathology.” Barlow’s ninth builds the whole book on one, with chapter 2 titled “An Integrative Approach to Psychopathology.” Coverage of the historical schools is standard, and a course that wants students to know where the ideas came from is served by any of the three.

Dr. Smerbeck’s Psychological Disorders makes the evaluation of scientific claims both a chapter and a running feature. Chapter 3 is titled “Science and Pseudoscience,” and the feature of the same name recurs through the book. FlatWorld’s own description of how it works: each instance “describes an alternative diagnostic or treatment approach, including the evidence for and against its use, and why it might appear to work when it actually does not.” The example given is homeopathy for anxiety disorders, in section 5.3. A companion feature identifies common myths and misconceptions and explains how each one arose and why it might be harmful.

Dr. Smerbeck’s Psychological Disorders gives Freud and other non-evidence-based material less space than a survey-first textbook allots that material. He treats Freud’s theories as pre-scientific, on the same reasoning that a medical textbook spends little time on the four humors.

Psychological Disorders teaches students what makes a scientific claim testable. Dr. Smerbeck’s example sets two claims side by side. A claim that alcohol abuse is more common among people with obsessive-compulsive disorder can be shown to be false, so it is a scientific hypothesis. A claim that unhappy feelings come from an unconscious childhood conflict with one’s parents cannot be shown false by any evidence, so it is not.

Psychological Disorders pairs its scientific material with a vignette for most of the disorders in the book. That pairing is the one Dr. Smerbeck asked for: crafted stories about people, and then the evidence.

Which to choose: Comer is a strong fit if you want the full historical survey of the theoretical schools and the classroom activities built around them, and Barlow if you teach the integrative model as the organizing framework; FlatWorld is the stronger fit if your syllabus includes teaching students to tell a testable claim from an untestable one.

What Support Does Each Publisher Provide When an Instructor Switches Psychopathology Textbooks?

Achieve, MindTap, and FlatWorld differ across four services an instructor relies on during a switch: student purchase, chapter reordering, accessibility documentation, and staffed support hours.

Student Purchase of Achieve, MindTap, or FlatWorld

Macmillan sells Achieve by subscription only, with purchase gated by a course ID you supply, which makes you the first step in every student’s purchase and the first call when the course ID does not work. Cengage sells MindTap directly and through the Unlimited subscription. FlatWorld students buy directly, with no course ID.

Reordering Comer, Barlow, or Smerbeck to Match Your Syllabus

FlatWorld adopters can reorder the chapters to follow their syllabus immediately. The same self-serve tools let an adopter add original work, embed campus resources, combine content from other FlatWorld titles, and edit the text down to the word. An adopter who would rather hand the job off can describe the book to a local FlatWorld representative, who handles the whole process.

A Macmillan custom edition starts with contacting a Custom Solutions specialist. The Custom Solutions page lists chapter reordering, original work, and campus resources as options. Cengage’s custom-solutions pages describe cutting or replacing chapters and adding readings, cases, exercises, or an instructor’s own material. They set an enrollment minimum of 20 for a CengageCompose book and 400 a year for custom digital solutions. Neither page carries a date, and the terms may have changed, so confirm them with Cengage before planning a custom edition of Barlow’s ninth. FlatWorld sets no enrollment minimum.

Accessibility Statements from FlatWorld, Macmillan, and Cengage

FlatWorld states conformance with WCAG 2.2 Level AA, one version newer than the WCAG 2.1 Level AA required under the ADA Title II final rule. Macmillan states that its standards “align with” Section 508 and WCAG 2.2 AA. Cengage states that “our current VPATs will still show gaps to compliance, so we can share updated VPATs when our remediation work is complete.” Those are three different kinds of statement, and the difference is the instructor’s to weigh with their disability services office.

Support Hours at Cengage, FlatWorld, and Macmillan

Cengage publishes a 24/7 support claim, a longer window than the hours FlatWorld publishes. FlatWorld publishes specific staffed hours rather than a round-the-clock claim: live chat and email to 1:00 AM Eastern most nights, phone to 8:30 PM Eastern, plus a local representative who stays the same across semesters. No published support hours were found on any Macmillan page.

Which to choose: Cengage is a strong fit if round-the-clock platform support is a firm requirement for your department; FlatWorld is the stronger fit if you would rather have a person whose name you know and who will build your custom book down to the individual word.

Which Psychopathology Textbook Fits My Course?

The choice among Comer, Barlow, and Smerbeck depends on how much it matters that your psychopathology textbook is organized around the DSM-5-TR. Comer’s twelfth edition and Barlow’s ninth include the current criteria inside chapters that follow the DSM-IV’s categories. If your syllabus is built around one of those books and you are comfortable working around that chapter structure, you can keep the book you know. If you want the book’s own structure to match the current manual, Smerbeck’s first edition follows the DSM-5-TR’s organizational structure from the first chapter to the last.

Dr. Smerbeck’s Psychological Disorders is a first edition, so fewer instructors have taught from that book than from Comer’s twelfth edition or Barlow’s ninth. Bay View Analytics’ 2021 to 2023 faculty research found that smaller specialized publishers led the three largest publishers on scope, accuracy, and supplements, a finding about publishers rather than about any single first edition.

Comer, Psychopathology: Science and Practice, 12e, is a strong fit if your course is built around clinical decision practice, if your slides, syllabi, and test items already come from an earlier edition, and if your students use Achieve in another course.

Barlow, Durand, and Hofmann, Psychopathology: An Integrative Approach to Mental Disorders, 9e, is a strong fit if you teach the integrative model as the organizing framework and if your students carry several Cengage courses.

Smerbeck, Psychological Disorders: The Science of Mental Health, v1.0, is the stronger fit if you want the book’s chapter organization to match the DSM-5-TR’s organization, if a large share of your room is filling a general-education requirement, and if a student price of $41.95 for Basic ($61.95 for Standard) with homework included changes who in your section buys the book.

Every FlatWorld comparison, across disciplines, is listed on the comparisons page.

Frequently Asked Questions

Talk to a real person. Your local FlatWorld representative can walk the chapter organization against your syllabus. Get started:

Sources

1. FlatWorld, Psychological Disorders: The Science of Mental Health, v1.0, catalog edition page and the book’s own Brief Contents. Read September 16, 2026.

2. Macmillan Learning, Psychopathology: Science and Practice, Twelfth Edition, product page and published table of contents. Read September 17, 2026.

3. Cengage, Psychopathology: An Integrative Approach to Mental Disorders, 9th Edition, product page. Read September 16, 2026.

4. Macmillan Learning store, student purchase options for Comer 12e. Read September 14, 2026.

5. Cengage student purchase options and Cengage Unlimited terms. Read September 16, 2026.

6. American Psychiatric Association, “The Organization of DSM-5” fact sheet. Read September 17, 2026.

7. FlatWorld, instructor supplement availability for the Smerbeck title. Confirmed by FlatWorld September 30, 2026.

8. FlatWorld product documentation: homework, LMS integration, customization, audiobook, SmartHelper, engagement dashboard.

9. FlatWorld accessibility statement, WCAG 2.2 Level AA. Read June 16, 2026.

10. Macmillan Learning accessibility page. Read July 6, 2026.

11. Cengage Group accessibility and VPAT page. Read September 15, 2026.

12. FlatWorld customer support hours. Read June 15, 2026.

13. American Psychological Association, editorial on the renaming of its journal in this field, via APA PsycNet. Read September 16, 2026.

14. Bay View Analytics, faculty research on textbook scope, accuracy, and supplements, 2021 to 2023.

15. Dr. Alan Smerbeck, author of Psychological Disorders: The Science of Mental Health, in conversation with FlatWorld, August and September 2026.

16. Macmillan Learning, LMS integration options page and Achieve platform page. Read September 24, 2026.

17. Cengage, LMS integration page and MindTap features page. Read September 24, 2026.

18. Author biographies from each publisher’s own pages: Macmillan Learning for Comer 12e and Cengage Learning Asia for Barlow 9e, read September 24, 2026, and FlatWorld for Smerbeck v1.0.

19. Macmillan Learning, AI Student Tutor page, and the AI Resources page linked from the Comer 12e product page. Read September 24, 2026.

20. Cengage, GenAI Student Assistant page and its course availability list. Read September 24, 2026.

21. Macmillan Learning, Custom Solutions page, linked from the Comer 12e product page. Read September 29, 2026.

22. Cengage, custom-solutions pages for CengageCompose and custom digital solutions (cengage.com/custom). Undated. Read September 30, 2026.

23. Cengage, Instructor Center table of contents for Barlow 9e. Read September 28, 2026.

This article is published by FlatWorld, which publishes one of the three textbooks compared. Prices, tables of contents, and accessibility statements are quoted from each publisher's own pages and dated in Sources and Citations above.