Psychology

Fundamentals of Psychological Disorders

Alexis Bridley; Lee W. Daffin Jr.

A free psychopathology textbook linking DSM-5-TR classifications with assessment, competing explanations and evidence about treatment.

Prerequisites

An introductory psychology course is recommended. Be comfortable distinguishing a classification rule from an explanation of why a disorder develops. Basic research-methods vocabulary will help with prevalence, comorbidity and treatment evidence; clinical training is not assumed for reading the text.

Edition
4
Publication Year
2026
Difficulty Level
Intermediate
Academic Level
Undergraduate
psychologyabnormal-clinicalopen textbook

01 / Reading Guide

Reading Guide

Who this book is for

For undergraduates beginning abnormal or clinical psychology and readers seeking a structured academic account of mental disorders. The modules support comparison across categories rather than learning isolated symptom lists. It is an educational foundation for further study, with practical clinical decisions requiring more extensive training and evidence.

Prerequisites

An introductory psychology course is recommended. Be comfortable distinguishing a classification rule from an explanation of why a disorder develops. Basic research-methods vocabulary will help with prevalence, comorbidity and treatment evidence; clinical training is not assumed for reading the text.

What it covers

Sixteen modules begin with definitions, explanatory models and clinical assessment, then examine mood, trauma-related, dissociative, anxiety, somatic, obsessive-compulsive, eating, substance-related, psychotic, personality and neurocognitive disorders. Childhood disorders and contemporary issues complete the sequence. Repeated headings connect clinical presentation with epidemiology, comorbidity, etiology and treatment.

How to use it

Read the first three modules before selecting a disorder block. Make a comparison table for two categories that could be confused, separating diagnostic criteria from mechanisms and risk factors. Explain what information is missing from a short case and why one symptom cannot settle the question. For treatment claims, identify the kind of evidence and the population studied before carrying a conclusion to another setting.

Edition and sources

The WSU live book identifies the fourth edition as August 2026 and retains a 2018 copyright notice. It was formerly titled Abnormal Psychology. The license page specifies CC BY-NC-SA 4.0. Classification and treatment discussions should be read in their edition context.

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