Lesson 3: Classification and Diagnosis of Psychopathology

Psychopathology

Refers to the study of nature, symptomology, development, and treatment of psychological disorders

Classification

Every person is unique, shaped by genetics, physiology, life experiences, and current circumstances, yet psychologists seek to understand and predict behavior by identifying common patterns through ____

Validity and Utility

Classification systems are central to all sciences, allowing phenomena to be organized, described, and related in meaningful ways. Two key aspects determine the adequacy of a classification system:

Validity

which refers to how accurately the system captures the nature of the entity being classified

• Does it accurately capture a real disorder?

Utility

which refers to the usefulness of the classification in practice (real world).

Categorical approach

In clinical psychology, classification can follow a _____, in which an individual either belongs to a diagnostic category or does not.

• Use primarily in DSM-5

• Clear and simple

• Meet the criteria or not

Example:

In diagnosing major depressive disorder, a person is either judged to meet criteria or not. Members of a categorical diagnosis should share similar characteristics.

Dimensional approach

Focuses on the degree to which a person exhibits certain traits or behaviors, placing them on a continuum (range/severity level of disorder)

For example, weight and height can be measured _____, while psychological constructs such as neuroticism or symptom intensity can also be assessed this way

Thomas Achenbach

Research by _____ illustrates the dimensional approach in child psychopathology.

Externalizing and Internalizing Problems

Dimensional Approach classified entities differ in the extent to which they possess certain characteristics or properties.

Using information from multiple informants and factor analysis, Achenbach identified two broad dimensions of problems:

Externalizing problems

which involve acting-out behaviors like aggression, stealing, or destroying property

Internalizing problems

which involve inwardly directed emotions such as sadness, worry, or withdrawal.

Achenbach System of Empirically Based Assessment (ASEBA)

By using a dimensional framework, psychologists can describe the intensity of a child’s externalizing and internalizing problems, rather than simply labeling the presence or absence of a disorder.

This work led to the ____, a set of empirically derived tools to measure competence and problems across the lifespan

is a collection of standardized tools designed to evaluate behavioral, emotional, and social concerns, as well as adaptive functioning, across the lifespan—from 1.5 years old to over 90 years of age (Achenbach & Rescorla, 2001).

Collateral informants

Achenbach System of Empirically Based Assessment (ASEBA)

These instruments aim to measure a wide range of psychological and adjustment difficulties using multiple informants, including selfreports and reports from individuals who are familiar with the person being assessed (referred to as ____)

Quantitative and qualitative

The ASEBA forms contain structured items that are ____ scored to generate empirically derived syndrome scales and DSM oriented scales.

Beyond numerical scoring, the system also gathers individualized ____ data that can support clinical interpretation and case conceptualization.

Diagnostic Systems

Regardless of approach, ____ apply rules to classify symptoms and yield a diagnosis that concisely describes an individual’s condition.

Diagnoses are widely used because they allow psychologists to organize and communicate information about disorders, determine eligibility for services (such as academic support for learning disabilities), and meet insurance requirements for reimbursement of psychological services.

However, diagnosis has potential drawbacks, including stigmatization and the possibility of inaccurate diagnoses leading to inappropriate or harmful treatment.

Overall, classification and diagnosis provide essential frameworks for understanding human behavior, guiding assessment, and planning effective psychological interventions.

Emil Kraepelin

Modern attempts to classify and diagnose abnormal human behavior began with ____, who studied dementia praecox (now schizophrenia) and manic-depressive insanity (now bipolar disorder), laying the foundation for current psychiatric diagnostic systems.

Dementia Praecox

Former name of Schizophrenia

Manic-depressive insanity

Former name of Bipolar Disorder

neo-Kraepelinian approach

views each diagnosis as a medical illness defined by specific criteria and emphasizes diagnostic reliability.

In recent decades, this approach has been supplemented by the prototype model, which recognizes that members of a diagnostic category may differ in the degree to which they represent the defining features of the category.

Same diagnosis is not equal to same symptoms

Applied to psychiatric diagnosis, this means that two people with the same diagnosis may not share exactly the same symptoms and may therefore require somewhat treatments.

Abnormal Behavior

Clinical psychologists provide services to people with and without diagnosable conditions, making it important to determine what constitutes abnormal behaviour.

Many individuals seek guidance on whether their experiences or symptoms are normal or abnormal.

is not simply rare, unusual, or bizarre; its determination depends heavily on context, including age and cultural expectations.

Draw line between normal/abnormal symptoms

Developmental psychopathology approach

examines problem behavior in the context of developmental milestones and recognizes that biological and psychological systems are constantly changing.

This approach emphasizes the importance of major transitions—such as starting daycare, learning to speak, entering high school, or moving into longterm care—as well as disruptions to typical development, including loss, poverty, or exposure to trauma.

Central to this approach is empirical knowledge of normal development, which allows psychologists to interpret behaviors relative to age-appropriate expectations.

Developmental psychopathology

considers both the current difficulties of the client and the likely course of the problem if untreated, drawing on extensive research in areas such as parenting, child neglect and abuse, family conflict, cognitive changes across the lifespan, and evolving societal values to inform diagnosis and intervention

Diagnosis

of mental disorders is never based on a single symptom; instead, it relies on a cluster of co-occurring symptoms.

Biological markers

Unlike many physical disorders, where laboratory tests such as X-rays or blood work can confirm a diagnosis, mental disorders currently lack comparable ____

Observations and Client Self-Reports

As a result, diagnostic systems for mental disorders rely primarily on ____ and ____, although information from multiple informants can also be valuable

Research Domain Criteria (RDoC)

The _____ framework introduced by the U.S. National Institute of Mental Health, seeks to address this limitation by integrating biological, cognitive, and self-report data to improve the validity of mental disorder diagnoses.

Determining abnormality is influenced by personal, cultural, and professional values, which makes reliance on scientific evidence crucial

Childhood depression

Historical biases illustrate this point: _____ was largely overlooked until the 1980s because prevailing psychoanalytic and behavioral models suggested that children could not experience depression in the same way adults do.

Children often express emotions differently, showing overt happiness or disinterest rather than verbal sadness, highlighting the need for developmentally informed diagnostic criteria.

Accurate diagnosis, therefore, requires attention to symptom clusters, developmental stage, and scientific evidence, rather than assumptions based solely on adult presentations or theoretical models.

Mental disorder

according to the DSM-5, is defined as a syndrome involving clinically significant disturbances in cognition, emotion regulation, or behavior, which reflect dysfunctions in psychological, biological, or developmental processes.

For a condition to be classified as a disorder, it must cause significant distress or impairment in social, occupational, or other important areas of functioning.

Distress, Deviance, Dysfunction, Danger, Duration

What are the 5Ds?

Barlow and Durand

According to ___ and ___ (Abnormal Psychology: An Integrative Approach), the 4D’s of abnormality are criteria used to help determine whether behavior can be considered abnormal

Deviance

Behavior, thoughts, or emotions that deviate from cultural or societal norms.

What is considered “normal” depends on cultural standards and context.

Example: Hearing voices when no one is present (outside of culturally acceptedspiritual or religious practices).

Distress

The behavior causes significant personal suffering or emotional pain to the individual.

However, not all abnormal behaviors involve ____ (e.g., some personality disorders where the individual may not feel distressed but others do).

Important indicator of psychopathology

Dysfunction

There is impairment in daily functioning, such as difficulty in work, school, relationships, or self-care.

Example: Severe anxiety that prevents a student from attending classes or completing academic task

Internal mechanism - unable to maintain the usual functioning

Danger

The behavior poses a risk of harm to oneself or others.

Example: Suicidal ideation, self-harm behaviors, or violent aggression toward others.

Disability

Addition to 5Ds - refers to the impairment in other areas of life

Duration

The behavior or symptoms persist for a clinically significant period of time, rather than being a brief or expected reaction to a situation.

Many psychological disorders require specific time criteria for diagnosis.

Example: Depressive symptoms lasting at least two weeks, or excessive worry occurring most days for at least six months

Anxiety and depression

In the Philippines, national data indicate a similar trend: according to the 2017 National Mental Health Survey conducted by the Department of Health, approximately 1 in 5 Filipinos (16–20%) have experienced a mental health problem in their lifetime, with _____ and ____ as the most common disorders

Despite this high prevalence, only a small proportion of Filipinos with mental disorders receive professional care, reflecting the global gap between mental health needs and access to services

Diagnostic and Statistical Manual of Mental Disorders (DSM)

is a primary diagnostic tool for North American mental health professionals, including clinical psychologists.

DSM-I (1952)

• First official classification in the US

• Strongly influenced by Psychodynamic theory

• Focused on psychodynamic explanations and provided vague descriptions of disorders.

• Lack criteria and credibility

DSM-II (1968)

• Psychodynamic assumptions became less prominent;

• increasing use of drug treatments (Psychopharmacology) and research on biological

• and neurological aspects led to more precise terminology

• More medical and biological perspective

• Still lack clear operational definition

DSM-III (1980)

• Major turning point under Robert Spitzer:

• Introduced an atheoretical approach (no psychodynamic theory bias)

• Provided detailed symptom criteria for each disorder

• Conducted field trials with thousands of patients and clinicians to improve diagnostic reliability

• Increased research compatibility

• Diagnosis is more scientific and standardized

Multiaxial system

provided a comprehensive, five-axis framework to evaluate mental health patients beyond just symptoms, improving diagnosis reliability.

Axis 1 - Clinical Disorders

Axis 2 - Personality and Intellectual Disorders

Axis 3 - Medical conditions

Axis 4 - Psychological stressors

Axis 5 - Global assessment of functioning

DSM-III-R (1987) & DSM-IV (1994)

• Refined diagnostic criteria through research and expert work groups

• Included international consultation

• Provided empirical foundation and global relevance

DSM-IV-Text Revision (2000)

• Updated scientific information and enhanced educational value without changing diagnostic criteria

• Axis 1 to 5 (Multiaxial axis classification)

DSM-5 (2013):

• developed through extensive research, international consultation, and field testing ·

• Faced unprecedented criticism:

  • Lack of transparency in development

  • Concerns about diagnostic inflation

  • Over-reliance on medical/biological models

  • Conflict of interest: 70% of task force members had pharmaceutical ties

• Field trials revealed poor reliability for some common disorders, e.g., depression and generalized anxiety disorder

• Axial 1-5 eliminated

• Global assessment of functional became assessment tools

• Include severity specifier

• Simplified documentation

• Integration of mental and physical health

• Cultural context-wise

• Lifespan Organization

• Preserve categorical but common is dimensional approach

• Increase emphasis in neuroscience

• Diagnostic revisions include:

  • ASD combined previous subtypes

  • Bereavement is excluded in depression

  • Added hoarding disorder and disruptive and dysregulation disorder

DSM-5 TR (2022)

• Text revision, updated prevalent rates, revised language for clarity

• Added prolong grief disorder

• Greater attention to inclusivity and equity in language

Severity specifier and cross-cutting symptoms measures

The DSM-5 primarily uses a categorical approach to classify mental disorders, meaning that each disorder is defined by specific criteria that must be met for a diagnosis.

However, recognizing that some disorders may be better represented along a continuum, the DSM-5 organizes disorders into clusters based on shared features.

For instance, disorders with internalizing symptoms— such as anxiety, depression, and somatic complaints—are grouped together, while those with externalizing symptoms—including impulsive behavior, conduct problems, and substance use—form another cluster.

• refers to the mild, moderate, severe

• spectrum nature of disorder

International Classification of Diseases

by WHO; covers all health conditions, including mental and behavioural disorders.

42 languages

Current Edition:

ICD-10 (1992); available in ____ and online for free, updated annually.

Global Use:

• Provides population-level health and mortality data (e.g., Canada).

• Adapted for clinical use in some countries (e.g., ICD-10-CM in the US for diagnosis, billing, and patient care).

ICD-11

Compatibility with DSM-5: Codes aligned; some differences in diagnostic classes and criteria (e.g., acute stress reaction).

____ Updates:

• Maintains DSM-5 organizational structure.

• Emphasizes clinical utility for real-world use.

• Includes clinical manual (general descriptions) and research manual (operational criteria)

International Classification of Functioning, Disability, and Health.

CF Companion System: _____

• Focuses on overall health and functioning rather than only diagnosis.

• Codes body functions, activity limitations, participation restrictions, and environmental factors.

• Especially relevant for rehabilitation, chronic illness, and pain management.

Severity-based predictions

• _____ (Kesslet et al., 2003)

• Disorders can be classified by severity, not just presence or absence.

  • Severe: 3.2% of population

  • Moderate: 8.7%

  • Mild: 16%

• Even mild disorders, though less severe, can have meaningful effects on a person’s future psychosocial functioning.

• Shows that mental health exists on a spectrum rather than a simple yes/no distinction.

Subthreshold symptoms

Individuals with mild disorders were 2.4 times more likely to develop later significant psychosocial problems compared to those with no disorder.

Suggests that even ______—those not meeting full diagnostic criteria—can have long-term consequences.

Functional disability below diagnostic threshold

____ Rai et al., 2010):

More than half of disability in mental disorders occurs in people who do not meet full diagnostic criteria. Indicates that traditional diagnoses may underestimate the burden of mental health issues in the population.

Kappa statistic

Goal since 1980s:

• Efforts focus on making sure different clinicians assign the same diagnosis for the same client. Reliability ensures consistency and fairness in clinical practice.

• DSM-5 findings: Field trials revealed that reliability is lower than desired, especially for less common disorders. Highlights ongoing difficulties in achieving consistent diagnoses across clinicians.

This is measured using _____

• Measures agreement beyond chance; higher values = better reliability.

• Kraemer et al. (2012) suggest κ ≥ .2 may be acceptable for complex diagnoses

• Shows that definitions of acceptable reliability are debated in psychiatry.

κ ≥ .6

Traditional standard: ____ (Spitzer et al., 2012), indicating substantial agreement.

Rarity of disorder, categorical vs. dimensional coding, method of evaluation

Factors affecting reliability:

1. _____: Uncommon conditions are harder to identify reliably.

2. _____: Treating symptoms as present/absent (categorical) reduces accuracy compared to measuring symptom severity on a continuum (dimensional).

3. _____: “Inter-rater” method (same interview reviewed) overestimates real-world agreement; “testretest” (independent interviews) gives a more realistic measure of reliability. Example (Chmielewski et al., 2015): Inter-rater kappa = .80 (reviewing same interview) Test-retest kappa = .47 (independent interviews)

4. Suggests previous DSM reliability estimates may have been overly optimistic.

Polythetic nature

• Same diagnosis can be applied to individuals with different symptom combinations.

• This flexibility helps clinicians capture real-world variability, but can reduce consistency

Impact on treatment:

• Variability in symptoms may mean that patients respond differently to the same treatment.

• Example: Two patients with depression may have very different predominant symptoms (cognitive vs. physical), and a medication may help one group but not the other.

• Suggests that treatment should be tailored to symptom profiles, not just diagnoses.

• Many attempts to define subtypes (e.g., for major depressive disorder) exist but have limited empirical support.

• Illustrates a limitation of current diagnostic systems: broad categories may mask important individual differences.

Validity

A valid diagnosis identifies a discrete disorder with clear boundaries.

Few mental disorders show strong ____; those that do usually have a biological basis (e.g., Down’s syndrome, Huntington’s disease).

Acute Stress Disorder (ASD)

Introduced to capture PTSD-like symptoms within 1 month of trauma.

Criticisms include:

• Dissociative symptom requirement not supported by research

• Weak link to later PTSD development

• Risk of pathologizing normal stress responses

• Current understanding: dissociation around trauma predicts PTSD better than ASD diagnosis itself.

• Shows how research influences diagnostic criteria over time.

Comorbidity

Simultaneous presence of two or more mental disorders.

Prevalence:

• Adults: 22% have two disorders, 23% have three or more (Kessler et al., 2005)

• Youth: 40% with one disorder also have another (Merikangas et al., 2010)

Consequences:

• Greater functional impairment in daily life

• Chronic mental health problems

• More physical health issues

• Increased health care usage

Research & clinical relevance:

• Comorbid patients are more complex to treat, requiring integrated care.

• Studies excluding comorbid individuals may underestimate treatment needs.

DSM-5 stance

Comorbidity challenges categorical assumptions:

• Many individuals meet criteria for more than one disorder, contradicting the idea that mental disorders are completely separate and nonoverlapping.

• This reality suggests that mental disorders may exist on continuous dimensions rather than rigid categories.

_____

• DSM-5 acknowledges that disorders may not be discrete entities, but no fully agreed-upon dimensional system yet exists.

• Researchers are exploring dimensional models to better represent the nature of mental disorders (Krueger, Watson, & Barlow, 2005; Widiger & Trull, 2007).

Hybrid view

Dimensionality within specific disorders (Depression example):

Debate exists over whether depression is a distinct category or part of a continuum of distress.

Research supports a ____: depression can be a discrete disorder and also exist on a spectrum from subclinical to clinical levels.

Self-report measures

• Emotional/cognitive symptoms (e.g., discouragement, loss of interest) → show dimensional trends

• Somatic symptoms (e.g., sleep disturbance, weight loss) → support categorical interpretation

Cross-disorder dimensional patterns

• Comorbidity is not just due to overlapping symptoms or methodological errors.

• Core pathological processes may underlie multiple symptom types across disorders (Krueger & Markon, 2006).

Internalizing vs. externalizing dimensions

Internalizing disorders: anxiety, depression, somatic symptoms

Externalizing disorders: impulsivity, disruptive behavior, substance use

Initially identified in children, these dimensions are cross-culturally consistent (Ethiopia, Iceland, Korea, Israel, Jamaica).

Adult studies confirm these dimensions are also relevant for adult psychopathology.

Single factor/Separate factor

Cross-cultural evidence: A study of 14 countries found: Depression, anxiety, somatic disorders → ____ (internalizing) Alcohol abuse → ____ (externalizing) Findings replicated in Australian adults (Wright et al., 2013) and include psychotic experiences as an additional dimension. Suggests that core dimensions of psychopathology may be universal, though expression can vary culturally

Implications for research and diagnosis

• Dimensional models may better account for comorbidity than strict categorical systems.

• Can improve understanding of underlying processes that generate multiple disorders.

• May inform more personalized interventions, targeting dimensions of symptoms rather than broad diagnostic categories.