Welcome to the fascinating world of Abnormal Psychology! This is one of the most practical and engaging options in the IB Psychology curriculum.
Abnormal Psychology is the study of mental illness—what causes it (etiology), how we classify it (diagnosis), and how we treat it. This chapter challenges you to think critically about what "normal" even means and helps develop empathy and understanding for those who experience psychological disorders.
Why is this important? Understanding the roots of psychological disorders is crucial not only for treating them but also for reducing the stigma surrounding mental health. We will apply the three core approaches (Biological, Cognitive, and Sociocultural) to specific disorders.
Section 1: What is Abnormality? Defining Psychopathology
Defining "abnormal" is harder than it sounds. What is considered unusual in one culture or situation might be perfectly normal in another. Psychologists use several criteria to distinguish between typical behaviour and psychopathology (the scientific study of mental disorders).
Four Key Criteria for Abnormality
No single criterion is enough on its own; usually, a combination is required to justify a diagnosis.
1. Statistical Infrequency
- Definition: Behaviour that is rare or statistically unusual.
- Example: Having an extremely high IQ is statistically infrequent, but it isn't considered a disorder. Similarly, severe depression is statistically rare in the general population.
- Limitation: It doesn't distinguish between desirable and undesirable rarity.
2. Deviation from Social Norms
- Definition: Behaviour that violates the unstated rules (social norms) about acceptable conduct in a given society.
- Example: Wearing a suit to the beach is unusual, but harmless. Walking naked down the street violates deeply embedded social norms and might suggest a disorder.
- Limitation: Norms change over time and vary dramatically between cultures (cultural relativism). What was considered "abnormal" 50 years ago (e.g., homosexuality) is not today.
3. Failure to Function Adequately (FFA)
- Definition: A person is unable to cope with the demands of everyday life, causing distress and impairment.
- Key Indicators: Inability to maintain personal hygiene, hold a job, or sustain relationships.
- Analogy: Think of a smartphone that can't run its essential apps—it's broken. If a person cannot manage their "life apps," they may be failing to function adequately.
4. Deviation from Ideal Mental Health
- Definition: Defines abnormality by looking at what makes a person healthy (mental health). If a person lacks certain attributes, they are considered abnormal.
- Attributes (Marie Jahoda, 1958): High self-esteem, resistance to stress, autonomy, accurate perception of reality.
- Limitation: These criteria are very demanding; almost no one meets all of them all the time.
Quick Review: Remember the criteria using the mnemonic S. D. F. I. (Statistical, Deviation from norms, Failure to function, Ideal mental health).
Section 2: Diagnosis and Classification
Diagnosis is the process of identifying and determining the nature of a disease or disorder by means of examination and classifying its signs and symptoms.
Key Diagnostic Manuals
To ensure consistency, clinicians globally use standardized manuals:
- DSM (Diagnostic and Statistical Manual of Mental Disorders): Primarily used in the USA. Currently in its 5th edition (DSM-5).
- ICD (International Classification of Diseases): Published by the World Health Organization (WHO), used globally (often preferred in Europe). Covers both mental and physical diseases.
Did You Know? Both the DSM and ICD are descriptive, meaning they focus on observable symptoms and don't try to explain the *cause* (etiology) of the disorder. This allows practitioners from different theoretical approaches to use the same classification system.
Challenges in Diagnosis
Diagnosis is not an exact science. Clinicians must interpret symptoms, which leads to issues with reliability and validity.
1. Reliability of Diagnosis
Reliability refers to the consistency of the diagnosis. If two different clinicians assess the same patient, will they reach the same conclusion? This is called inter-rater reliability.
- Issue: If the diagnostic criteria are vague, clinicians might interpret symptoms differently, leading to low reliability.
2. Validity of Diagnosis
Validity refers to the accuracy of the diagnosis. Does the diagnosis reflect a real, distinct disorder, and does it lead to effective treatment?
- Issue: Since many symptoms overlap (e.g., anxiety and depression), it can be hard to determine if the person truly has Disorder A or Disorder B, or both (comorbidity).
3. Ethical and Sociocultural Considerations
Diagnosis can have profound consequences:
- Stigma and Labelling: A diagnostic label (e.g., "schizophrenic") can lead to social isolation, discrimination, and prejudice.
- Self-Fulfilling Prophecy: Once labelled, the individual might internalize the symptoms and begin to act according to the expected role of a person with that disorder (e.g., "I am depressed, so there is no point in trying.").
- Cultural Bias: Diagnostic systems developed primarily in Western cultures might fail to accurately diagnose individuals from non-Western backgrounds. Symptoms expressed differently across cultures (e.g., distress expressed physically rather than emotionally).
Key Takeaway: Diagnosis is essential for consistent communication and treatment planning, but it must be approached carefully due to the risks of misdiagnosis, stigma, and cultural bias.
Section 3: Etiology – Explaining Abnormal Behaviour (The Approaches)
Etiology is the study of the causes or origins of a disorder. We examine how the Biological, Cognitive, and Sociocultural approaches explain why disorders develop.
A. The Biological Approach to Etiology
This approach focuses on physiological factors—the hardware of the human system.
1. Genetic Predisposition
Disorders often run in families. Research (like twin and adoption studies) suggests a genetic vulnerability (diathesis) to certain conditions, such as depression or schizophrenia. Genes do not guarantee a disorder, but increase the risk.
2. Neurotransmitter Imbalance
Abnormal levels or functioning of key brain chemicals can contribute to disorders.
- Example: The Serotonin Hypothesis suggests low levels of the neurotransmitter serotonin are linked to clinical depression.
- Example: Excessive dopamine activity is often implicated in positive symptoms of schizophrenia (e.g., hallucinations).
3. Brain Abnormalities
Differences in brain structure or function, often revealed through neuroimaging (fMRI, PET scans), can be linked to disorders.
- Example: Reduced grey matter volume in the prefrontal cortex is sometimes observed in individuals with major depressive disorder, potentially affecting emotional regulation.
Biological Key Takeaway: Biology provides the vulnerability (the genetic or neurochemical "weakness").
B. The Cognitive Approach to Etiology
This approach focuses on how thinking patterns, beliefs, and schemas contribute to the onset and maintenance of disorders.
1. Cognitive Schemas and Biases
Individuals with certain disorders often process information in a biased, negative way.
- Example: A person with depression might selectively pay attention only to negative events (confirmation bias) and ignore positive ones.
2. Beck’s Cognitive Triad (for Depression)
Psychologist Aaron Beck proposed that depression is caused by negative thinking about three main areas:
- The Self ("I am worthless.")
- The World/Experiences ("Everyone is against me.")
- The Future ("Nothing will ever get better.")
3. Attributional Styles
This refers to how people explain the causes of events. A pessimistic attributional style involves explaining negative events as:
- Internal: It's my fault.
- Stable: It will always be this way.
- Global: It affects every part of my life.
This style of thinking increases vulnerability to depression.
Cognitive Key Takeaway: Disorders arise from maladaptive thinking patterns, negative interpretations, and faulty logical reasoning.
C. The Sociocultural Approach to Etiology
This approach focuses on the role of the environment, interpersonal relationships, poverty, culture, and society in the development of disorders.
1. Environmental Stressors
Stressful life events, such as loss of a job, divorce, or trauma (e.g., poverty or abuse), significantly increase the risk of developing a disorder. Lack of social support exacerbates this risk.
2. Sociocultural Factors and Symptom Expression
Culture influences how distress is experienced and expressed (cultural variations in symptoms).
- Example: In Western cultures, depression is often expressed psychologically (sadness, hopelessness). In some Asian cultures, it may be expressed through physical symptoms (headaches, body pain)—a phenomenon known as somatization.
- Concept: Culture-Bound Syndromes are disorders unique to specific cultures (e.g., Koro, an anxiety disorder found in Southeast Asia where a person fears their genitals are shrinking).
3. Labelling and Social Identity
As discussed in diagnosis, societal reaction to an individual's behaviour (labelling them as "sick") can reinforce the disorder and prevent recovery.
Sociocultural Key Takeaway: The context (society, culture, and environment) provides the trigger or maintains the disorder, particularly through chronic stress and lack of support.
D. Synthesis: The Diathesis-Stress Model (DSM)
Don't worry if all three approaches seem contradictory! Most psychologists use the Diathesis-Stress Model to explain how they interact—this is a fantastic model for synthesis (evaluation).
What is the Diathesis-Stress Model?
The model argues that a person may have a pre-existing diathesis (vulnerability), which is often biological or cognitive, but the disorder will only manifest if they encounter sufficient stress (environmental or sociocultural triggers).
- Diathesis (The Vulnerability): Genetic predisposition, neurotransmitter imbalance, or negative cognitive schema.
- Stress (The Trigger): Loss of a loved one, chronic poverty, traumatic event, or high expressed emotion in the family.
Simple Analogy: Imagine a match (diathesis) and gasoline (stress). Neither is dangerous on its own, but combined, they cause a fire (disorder).
Final Key Takeaway: Abnormal behaviour is rarely caused by a single factor. The most comprehensive explanations always integrate biological, cognitive, and sociocultural components via models like the Diathesis-Stress Model.