DSM-5 Classification, Anxiety, OCD, PTSD, and Mood Disorders

DSM-5 Classification, Anxiety, OCD, PTSD, and Mood Disorders

Defining Psychological Disorders

Abnormal psychology is the scientific study of abnormal behavior, thoughts, and emotions aimed at describing, predicting, explaining, and treating abnormal patterns of functioning. Defining what constitutes a psychological disorder can be challenging because human behavior exists along a continuous spectrum. Clinicians and researchers typically evaluate psychological functioning using the Four Ds framework:

1. Deviance: Behaviors, thoughts, or emotions that differ significantly from societal norms, cultural expectations, or statistical averages. What is considered deviant depends heavily on cultural context, social values, and historical era.
2. Distress: Subjective personal feelings of suffering, emotional pain, or internal turmoil experienced by the individual. Internal distress is a central feature of conditions like depression and anxiety disorders.
3. Dysfunction: Significant interference with daily operational functioning. Dysfunctional behavior impairs an individual's ability to maintain gainful employment, fulfill routine social and family roles, care for basic personal needs, or sustain healthy interpersonal relationships.
4. Danger: Behaviors, thoughts, or urges that pose a direct physical threat to oneself (such as suicidal ideation or self-harm) or to others. Although public perception often links mental illness with violence, danger is present in only a small minority of individuals diagnosed with psychological disorders.

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The DSM-5-TR Classification System

The primary diagnostic tool used by mental health professionals in North America is the Diagnostic and Statistical Manual of Mental Disorders, published by the American Psychiatric Association and currently in its DSM-5-TR (Text Revision) edition. The DSM-5-TR provides standardized, categorical criteria and descriptive definitions for over 300 mental disorders. Diagnostic criteria specify the exact symptoms required for a diagnosis, the minimum duration symptoms must persist, and the degree of impairment or distress required.

Benefits and Criticisms of Diagnostic Labeling

• Benefits: Standardized diagnostic labels facilitate clear, consistent communication among mental health providers, guide evidence-based treatment planning, enable epidemiological research, and assist patients in securing insurance reimbursement and specialized educational support.
• Criticisms: Diagnostic labels can foster enduring social stigma, self-fulfilling prophecies, and overpathologization of normal human distress. Labels may lead clinicians to view an individual through a diagnostic lens rather than seeing their complete human experience.

In a classic 1973 study titled "On Being Sane in Insane Places", researcher David Rosenhan investigated the reliability and impact of psychiatric diagnoses. Rosenhan and seven mentally healthy colleagues ("pseudopatients") gained admission to various psychiatric hospitals by claiming they heard auditory hallucinations saying words like "empty," "dull," and "thud." Once admitted, all pseudopatients immediately ceased simulating any symptoms and acted completely normally. Nevertheless, hospital staff interpreted their normal behaviors—such as keeping a personal journal—through the lens of their diagnostic label (e.g., documenting "patient displays pathological writing behavior"). None of the pseudopatients were identified by staff as sane, and they were discharged with diagnoses of "schizophrenia in remission," demonstrating the powerful bias of diagnostic labels.

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Explanatory Models of Psychopathology

Psychologists employ distinct theoretical models to explain the origin and development of psychological disorders:

• Medical Model: Conceptualizes psychological disorders as biological diseases with underlying organic causes (such as genetic mutations, neurochemical imbalances, or brain structural abnormalities) that require physical diagnosis and medical/pharmacological treatment.
• Biopsychosocial Model: Asserts that psychological disorders emerge from a complex, dynamic interplay of biological factors (genetics, brain chemistry), psychological dynamics (thought patterns, emotional regulation, coping mechanisms), and sociocultural contexts (socioeconomic status, family support, cultural expectations).
• Diathesis-Stress Model: Proposes that individuals possess an inherent diathesis (a biological, genetic, or cognitive vulnerability) that remains dormant until triggered by environmental stress (such as life trauma, loss, or chronic strain). The severity of a disorder depends on the combination and magnitude of both the underlying vulnerability and the external stressor.

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Anxiety Disorders

Anxiety disorders are characterized by persistent, excessive fear (an emotional response to a real or perceived imminent threat) and anxiety (anticipation of a future threat), accompanied by significant behavioral disturbances designed to avoid fear-inducing triggers.

• Generalized Anxiety Disorder (GAD): Marked by chronic, excessive, uncontrollable worry about a variety of everyday life events or activities, lasting for at least six months. Associated physical symptoms include restlessness, muscle tension, fatigue, difficulty concentrating, irritability, and sleep disruption. GAD is linked to reduced activity of the inhibitory neurotransmitter GABA.
• Panic Disorder: Defined by recurrent, unexpected panic attacks—sudden, intense surges of acute fear or terror that reach a peak within minutes. Physical symptoms include heart palpitations, chest pain, shortness of breath, trembling, sweating, dizziness, and intense fears of dying or losing control. Panic disorder often leads to persistent apprehension about future attacks.
• Agoraphobia: Intense fear or anxiety regarding two or more public environments (e.g., using public transportation, being in open spaces, standing in lines, or being in crowds) stemming from thoughts that escape might be difficult or help unavailable if panic symptoms occur. Individuals frequently avoid these situations or require a companion.
• Specific Phobias: Intense, irrational fear and active avoidance of a specific object or situation (e.g., spiders [arachnophobia], heights [acrophobia], flying, or blood-injection-injury). The fear is out of proportion to the actual danger posed.
• Social Anxiety Disorder (Social Phobia): Pronounced, persistent fear of social or performance situations in which the individual is exposed to potential scrutiny, judgment, or negative evaluation by others.

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Obsessive-Compulsive and Related Disorders

Obsessive-Compulsive Disorder (OCD) is characterized by the presence of obsessions, compulsions, or both:

• Obsessions: Intrusive, recurrent, unwanted thoughts, urges, or mental images that cause severe anxiety or distress (e.g., persistent fears of contamination, intrusive thoughts of harm, or excessive need for symmetry).
• Compulsions: Repetitive, rigid behaviors (e.g., excessive handwashing, checking locks, ordering items) or mental acts (e.g., counting, repeating phrases) that an individual feels driven to perform in response to an obsession. Compulsions are performed to reduce anxiety or prevent a feared catastrophe, though they are not realistically connected to the threat.

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Trauma- and Stressor-Related Disorders

Post-Traumatic Stress Disorder (PTSD) develops following exposure to actual or threatened death, serious injury, or sexual violence. Symptoms must persist for over one month and impair daily functioning across four primary symptom clusters:

1. Intrusions: Distressing memories, recurrent traumatic nightmares, or involuntary flashbacks where the individual feels or acts as if the traumatic event were recurring.
2. Avoidance: Persistent avoidance of trauma-related internal thoughts, feelings, or external reminders (people, places, activities).
3. Negative Alterations in Cognition and Mood: Inability to recall key aspects of the trauma, persistent negative beliefs about oneself or the world, distorted self-blame, detachment from others, and inability to experience positive emotions.
4. Hyperarousal and Reactivity: Irritability, hypervigilance, exaggerated startle response, difficulty concentrating, and sleep disturbance.

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Depressive and Bipolar Disorders

Depressive Disorders

• Major Depressive Disorder (MDD): Requires at least one major depressive episode lasting at least two weeks, featuring either depressed mood for most of the day or anhedonia (loss of interest or pleasure in almost all activities). Patients must also present at least four additional symptoms: significant weight/appetite changes, insomnia or hypersomnia, psychomotor agitation or retardation, chronic fatigue, feelings of worthlessness or excessive guilt, impaired concentration, and recurrent thoughts of death or suicidal ideation.
• Persistent Depressive Disorder (Dysthymia): A chronic, milder form of depression featuring depressed mood occurring for most of the day, for more days than not, for at least two years.

Bipolar Disorders

• Bipolar I Disorder: Defined by at least one full manic episode—a distinct period of abnormally elevated, expansive, or irritable mood and abnormally increased energy or activity lasting at least one week. Manic symptoms include grandiosity, decreased need for sleep, flight of ideas, distractibility, and engagement in high-risk activities. Major depressive episodes are common but not required for diagnosis.
• Bipolar II Disorder: Characterized by at least one hypomanic episode (a milder form of mania lasting at least four days without severe impairment or psychosis) AND at least one major depressive episode.
• Cyclothymic Disorder: A chronic condition lasting at least two years featuring fluctuating periods of hypomanic symptoms and depressive symptoms that do not meet full criteria for major episodes.

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Etiology of Mood Disorders

• Biological Factors: Strong genetic component shown in twin studies. Neurochemically, depression is linked to low levels of serotonin and norepinephrine, whereas mania involves overactivity of norepinephrine.
• Beck's Cognitive Triad: Psychiatrist Aaron Beck proposed that depressed individuals maintain automatic negative cognitive schemas regarding:
  1. The Self ("I am defective and unlovable")
  2. The World / Experience ("The world is harsh and demanding")
  3. The Future ("Things will never get better")
• Learned Helplessness & Attributional Style: Martin Seligman observed that dogs exposed to inescapable shocks eventually ceased trying to escape even when escape became possible. Applied to human depression, individuals develop a pessimistic attributional style, explaining negative events as:
  • Internal: "It is entirely my fault."
  • Stable: "This failure will last forever."
  • Global: "This ruins every aspect of my life."

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Summary Comparison of Diagnostic Categories