Topic 5.3 Notes – Explaining and Classifying Psychological Disorders

What Makes a Pattern a Psychological Disorder

There is no single test for “disorder.” Clinicians look at several indicators together and always in context.

The three indicators

• Distress means significant emotional suffering, like intense fear, sadness, guilt, or confusion.
  • Distress by itself does not prove a disorder. Grief after a death or anxiety before a big exam can be normal.
  • Some people report little distress because they lack insight into the problem.
• Dysfunction means the pattern interferes with daily life.
  • It can affect school, work, relationships, self-care, or decision-making.
  • What matters is severity, persistence, and impairment. A normal reaction becomes disordered when it seriously disrupts functioning.
• Deviation from social norms means behavior differs from what a culture or situation expects.
  • Unusual does not automatically mean disordered.
  • Norms vary by culture, age, time period, and setting, so context matters a lot.

A possible psychological disorder is often understood as involving some combination of distress, dysfunction, and deviation from social norms.

One common mistake is thinking dangerousness defines disorder. It does not. Many people with psychological disorders are not dangerous.

A quick distinction helps here:

• Definition asks whether behavior counts as disordered.
• Classification asks what category it fits.
• Explanation asks what caused or maintains it.

Diagnosis and Classification

A diagnosis is a trained professional’s judgment using evidence-based assessment. It is not self-diagnosis, one odd behavior, or an online checklist.

Clinicians use multiple sources of evidence:

• clinical or structured interviews
• behavioral observation
• psychological tests and symptom measures
• medical, developmental, educational, and family history when relevant
• ruling out substances, sleep deprivation, injury, or medical conditions

Good diagnosis aims for two things:

DSM

DSM stands for Diagnostic and Statistical Manual of Mental Disorders.

• Made by the American Psychiatric Association
• Main system used in the United States
• Gives diagnostic categories and criteria

ICD

ICD stands for International Classification of Diseases.

• Made by the World Health Organization
• Used internationally
• Includes mental and behavioral disorders

Both systems are revised as research improves reliability, validity, and cultural fit.

Why Diagnosis Helps and Why It Can Harm

A diagnosis can help because it:

• gives a name for a pattern of symptoms
• improves communication among professionals
• guides treatment and support
• helps research
• increases access to insurance, accommodations, and services
• can reduce self-blame

It can also harm because it may lead to:

• stigma and stereotyping
• shame or discrimination
• reducing a person to a label
• overdiagnosis, underdiagnosis, or misdiagnosis
• treating the label like a full explanation of cause
• self-fulfilling expectations

Culture and bias matter the whole time. Racism, sexism, ageism, class bias, and ableism can affect who gets diagnosed and how symptoms are interpreted. Culturally accepted practices should not be mislabeled as pathology, and fear of stigma can keep people from reporting symptoms.

Perspectives on the Causes of Psychological Disorders

Most psychologists use an eclectic approach, which means combining more than one perspective.

• Behavioral: symptoms come from maladaptive learned associations and reinforcement
  (classical conditioning and operant conditioning)
• Psychodynamic: symptoms grow from unconscious conflicts and childhood experiences
  (Freud background)
• Humanistic: lack of social support or blocked personal growth contributes to problems
  (Rogers and Maslow background)
• Cognitive: maladaptive thoughts, beliefs, and interpretations drive distress
• Biological: genes, brain function, neurotransmitters, hormones, illness, or prenatal factors matter
• Sociocultural: family, discrimination, poverty, cultural expectations, and social conditions shape disorders
• Evolutionary: some problems may reflect behaviors or mental processes that reduce survival, or overactive systems that were once adaptive

Interaction Models

These models reject one-cause explanations.

Biopsychosocial model

The biopsychosocial model says disorders can come from interacting biological, psychological, and social factors, as in the overlapping-circle diagram here.

• biological factors like genes, brain chemistry, hormones, health
• psychological factors like thoughts, emotions, learning history, coping
• sociocultural factors like family, peers, culture, discrimination, community stress

Biopsychosocial model

Diathesis-stress model

The diathesis-stress model is more specific. It says a genetic vulnerability plus stressful life experiences increases risk.

• Vulnerability alone does not guarantee a disorder.
• Stress alone does not affect everyone the same way.
• The phrase to remember is genes load the gun, environment pulls the trigger.

So the distinction is simple:

• Biopsychosocial is the broader model.
• Diathesis-stress is one specific gene-environment interaction model.