5.3 Explaining and Classifying Psychological Disorders
- Syllabus
- 2025
- Topic
- 5.3
- Level
- —
Learning objectives
5.3A—Describe the approaches used to define behaviors and mental processes as psychological disordersDescribe the approaches used to define behaviors and mental processes as psychological disorders.• Level of dysfunction, perception of distress, and deviation from the social norm are all factors used to identify psychological disorders.• Diagnosing or classifying psychological disorders has positive and negative consequences depending on the nature of the disorder, the individual being diagnosed, and the presence of cultural/societal norms, stigma, racism, sexism, ageism, and discrimination.• Diagnosing psychological disorders requires specialized training and the use of evidencebased diagnostic tools. The American Psychiatric Association developed the Diagnostic and Statistical Manual (DSM) of Mental Disorders to classify mental disorders. The World Health Organization developed the International Classification of Mental Disorders (ICD) to classify mental disorders. These classification systems are updated regularly to be responsive to new research and practice advances.5.3B—Explain how psychological perspectives define psychological disordersExplain how psychological perspectives define psychological disorders.• Most psychologists employ an eclectic approach (using more than one psychological perspective) when diagnosing and treating clients.• The behavioral perspective proposes that the causes of mental disorders focus on maladaptive learned associations between or among responses to stimuli.• The psychodynamic perspective proposes that the causes of mental disorders focus on unconscious thoughts and experiences, often developed during childhood.• The humanistic perspective proposes that the causes of mental disorders focus on a lack of social support and being unable to fulfill one’s potential.• The cognitive perspective proposes that the causes of mental disorders focus on maladaptive thoughts, beliefs, attitudes, or emotions.• The evolutionary perspective proposes that the causes of mental disorders focus on behaviors and mental processes that reduce the likelihood of survival.• The sociocultural perspective proposes that the causes of mental disorders focus on maladaptive social and cultural relationships and dynamics.• The biological perspective proposes that the causes of mental disorders focus on physiological or genetic issues.5.3C—Explain how interaction models define psychological disordersExplain how interaction models define psychological disorders.• The biopsychosocial model assumes that any psychological problem potentially involves a combination of biological, psychological, and sociocultural factors.• The diathesis-stress model assumes that psychological disorders develop due to a genetic vulnerability (diathesis) in combination with stressful life experiences (stress).
Identification Requires Impairment, Context, and Evidence
| Identification factor | Question it raises |
|---|---|
| Dysfunction | Does the pattern interfere with important areas of functioning? |
| Perceived distress | Does the person experience significant suffering or difficulty? |
| Deviation from social norms | Is the pattern outside expectations in the relevant social and cultural context? |
These factors are considered together and in context. Deviation alone is not enough: cultural and societal norms influence judgment, and racism, sexism, ageism, stigma, or other discrimination can distort who is labeled and how a diagnosis is received.
| Classification system | Developer | Role |
|---|---|---|
| DSM | American Psychiatric Association | Classifies mental disorders |
| ICD | World Health Organization | Classifies mental disorders |
Classification can support communication, evidence-based decisions, and access to appropriate help, but it can also contribute to stigma or biased treatment. Diagnosis therefore requires specialized training and evidence-based tools. DSM and ICD are updated as research and practice advance.
Unusual behavior is not automatically disordered, and a checklist used without specialized training is not a valid diagnosis. Classification describes a clinically evaluated pattern, not the whole person.
Perspectives Locate Causes in Different Processes
| Perspective | Primary causal focus |
|---|---|
| Behavioral | Maladaptive learned associations among stimuli and responses |
| Psychodynamic | Unconscious thoughts and experiences, often developing in childhood |
| Humanistic | Limited social support and inability to fulfill one's potential |
| Cognitive | Maladaptive thoughts, beliefs, attitudes, or emotions |
| Evolutionary | Behaviors or mental processes that reduce likelihood of survival |
| Sociocultural | Maladaptive social and cultural relationships or dynamics |
| Biological | Physiological or genetic issues |
To identify a perspective, locate the proposed cause—not the symptom being described. A learned association indicates a behavioral explanation; maladaptive belief patterns indicate a cognitive explanation; a physiological or genetic mechanism indicates a biological explanation.
An eclectic approach deliberately uses more than one psychological perspective when diagnosing or treating a client. It can combine complementary explanations rather than assuming that one perspective accounts for every contributing factor.
A perspective is a framework for explaining possible causes; it is not itself a disorder or a diagnostic test. Multiple perspectives can propose different mechanisms for the same observed pattern.
Interaction Models Combine Risk Factors
| Model | Factors combined | Core claim |
|---|---|---|
| Biopsychosocial | Biological, psychological, and sociocultural | Any psychological problem may involve a combination across these domains |
| Diathesis-stress | Genetic vulnerability (diathesis) and stressful life experience | Disorder develops through the combination of vulnerability and stress |
A biopsychosocial explanation might examine a physiological predisposition, maladaptive beliefs, and a stressful social environment together. The model organizes kinds of contributors; it does not require that all three contribute equally in every case.
In a diathesis-stress explanation, a genetic vulnerability may not produce a disorder on its own, and a stressful experience may not affect every person in the same way. Risk changes through their combination.
The models are not interchangeable. Biopsychosocial is a broad multi-domain framework; diathesis-stress is a specific vulnerability-by-stress mechanism. Neither model says that one factor alone guarantees a disorder.