Abnormal Psychology

Abnormal psychology is the HL extension unit in IB Psychology. It examines how psychological disorders are defined, classified, and explained, integrating the biological, cognitive, and sociocultural levels of analysis. Students must understand competing explanations for specific disorders and critically evaluate the treatments derived from each approach. This unit draws heavily on material from the three core levels of analysis, making it an ideal topic for demonstrating integrative thinking.

The strength of the abnormal psychology unit lies in its explicit requirement to apply all three levels of analysis to a single disorder. This integrative approach mirrors clinical practice, where a psychiatrist might prescribe SSRIs (biological), a therapist might implement CBT (cognitive), and a social worker might address environmental stressors (sociocultural) — often simultaneously. The diathesis-stress model, which posits that biological vulnerability interacts with environmental triggers, is a recurring framework that exemplifies this integration. Students should note that while each level of analysis offers a partial explanation, no single level is sufficient on its own. The challenge in abnormal psychology is to evaluate which explanations and treatments are most effective, appropriate, and ethical for specific disorders and populations, with particular attention to cultural variation in symptom expression and help-seeking behaviour.

Contents

• Anxiety Disorders — phobias and OCD, including biological, behavioural, and cognitive explanations and treatments.
• Depression — biological, cognitive, and sociocultural explanations of depression and approaches to treatment.
• Treatment Evaluation — evaluating the effectiveness, appropriateness, and ethical considerations of psychological treatments.

Key Concepts

• Abnormality — a deviation from social norms, statistical infrequency, failure to function adequately, or deviation from ideal mental health. No single definition is sufficient on its own.
• Diagnosis and classification — the process of identifying a disorder using a diagnostic system such as the DSM-5 or ICD-11. Classification enables consistent treatment and research, but is subject to issues of reliability and validity.
• Biological explanations — genetic predisposition, neurotransmitter imbalances (e.g., low serotonin in depression), and neural correlates (e.g., amygdala hyperactivity in anxiety). These explanations support biomedical treatments such as medication.
• Cognitive explanations — maladaptive thought patterns, negative schemas, cognitive biases, and faulty information processing (e.g., Beck”s cognitive triad for depression). These support cognitive-behavioural treatments.
• Sociocultural explanations — social stressors, cultural norms, poverty, and social learning as contributors to disorder onset and maintenance.
• Comorbidity — the co-occurrence of two or more disorders in the same individual, which complicates diagnosis and treatment.

Exam Focus

Paper 2 questions on abnormal psychology in most cases require:

• Explaining one or more disorders using at least two levels of analysis (biological, cognitive, sociocultural).
• Evaluating treatments with reference to effectiveness, appropriateness, and ethical considerations.
• Discussing cultural and gender considerations in diagnosis.
• Comparing individual and group approaches to treatment.
• Using specific studies as supporting evidence for each explanation (e.g., Gottesman for genetic explanations of depression, Beck for cognitive explanations).

Worked Examples

Example 1: Explaining Depression Using Two Levels of Analysis

Problem: Explain depression using biological and cognitive explanations. Solution: Biological: Depression is associated with low serotonin levels and genetic predisposition. Gottesman’s twin study found higher concordance rates for depression in monozygotic twins than dizygotic twins, supporting a genetic component. Treatment: SSRIs increase serotonin availability. Cognitive: Beck’s cognitive triad proposes that depressed individuals hold negative views about themselves, the world, and the future. Negative schemas bias information processing toward negative interpretations. Treatment: CBT aims to identify and restructure maladaptive thoughts. Integrating both levels: biological vulnerability (genetics, neurotransmitters) may create a predisposition that is activated or maintained by cognitive patterns.

Example 2: Evaluating Diagnosis and Classification

Problem: Discuss one issue with the classification of psychological disorders. Solution: Cultural bias in the DSM-5: diagnostic criteria were developed primarily in Western contexts and may not apply universally. For example, some cultures express depression through somatic (physical) symptoms rather than psychological ones, leading to underdiagnosis or misdiagnosis. This affects the validity of the classification system. The ICD-11 has attempted to address this by incorporating culture-specific concepts, but the problem persists.

Common Pitfalls

• Confusing biological and cognitive treatments: Biological treatments (medication, ECT) target physiological causes; cognitive treatments (CBT, cognitive restructuring) target thought patterns. Ensure the treatment matches the explanation.
• Listing studies without evaluation: When citing a study (e.g., Gottesman, Beck), always evaluate its methodology, sample, and generalisability rather than directly describing its findings.
• Not addressing comorbidity: Many disorders co-occur (e.g., depression and anxiety). Discussing comorbidity shows deeper understanding of abnormal psychology.

Assessment Overview

Abnormal psychology is assessed on Paper 2 (HL only).

Paper 2 — ERQ (22 marks):

• Students answer two questions from a choice of three options (abnormal psychology, developmental psychology, health psychology, or psychology of human relationships).
• Response length: approximately 600—700 words.
• Command terms: discuss, evaluate, to what extent, compare and contrast, examine.
• Questions require integration of two or more levels of analysis and/or evaluation of treatments.
• Structure: introduction defining the disorder or concept, body paragraphs presenting explanations from different levels of analysis or treatment approaches, critical evaluation of supporting studies and their methodologies, cultural and gender considerations, and a reasoned conclusion weighing competing explanations.
• Mark bands assess: accuracy of knowledge, depth of analysis, integration of multiple levels of analysis, evaluation of research methods (sample size, design, controls), discussion of cultural bias in diagnosis and treatment, and synthesis of evidence into a coherent argument.

Key command terms for abnormal psychology:

• Discuss: Present and consider multiple perspectives, studies, or explanations; weigh evidence for and against.
• Evaluate: Make an appraisal by weighing strengths and limitations of theories, studies, or treatments.
• To what extent: Consider the merits or otherwise of an argument or concept; reach a substantiated judgement.
• Compare: Describe two or more approaches, noting similarities and differences.

Research Methods Connection

Research in abnormal psychology must address the practical and ethical challenges of studying clinical populations:

• Clinical case studies: In-depth analysis of individuals diagnosed with a disorder. Case studies provide rich qualitative data and are essential for rare conditions, but cannot establish generalisable causal relationships. Treatment cases (e.g., Little Hans for phobias) are historically important but methodologically weak by modern standards.
• Correlational studies: Used to investigate associations between risk factors and disorders (e.g., correlating serotonin levels with depression severity). Cannot determine causation, though longitudinal designs can establish temporal precedence. Natural experiments (e.g., studying depression rates after natural disasters) can approximate causal inference.
• Randomised controlled trials (RCTs): The gold standard for evaluating treatment efficacy. Participants are randomly assigned to treatment or control (placebo or alternative treatment) conditions. Double-blind designs prevent both participant and experimenter bias. Limitations include attrition, ethical issues with withholding treatment, and the difficulty of blinding in psychotherapy studies.
• Meta-analyses: Statistical synthesis of findings across multiple studies, increasing statistical power and providing an overview of the evidence base. Kirsch et al.’s (2008) meta-analysis of antidepressant efficacy challenged the assumption that SSRIs are substantially more effective than placebo for mild to moderate depression.
• Diagnostic reliability studies: Inter-rater reliability studies test whether different clinicians arrive at the same diagnosis using DSM-5 or ICD-11 criteria, addressing the validity of the classification system itself.

Key Studies

Summary

Abnormal psychology (HL) examines how psychological disorders are defined, classified, and explained using the biological, cognitive, and sociocultural levels of analysis. Key topics include anxiety disorders (phobias, OCD), depression, and treatment evaluation. Students must integrate explanations from multiple levels and evaluate treatments in terms of effectiveness, appropriateness, and ethical considerations.