Psychological Disorders: Classification, Personality, and Dissociative Disorders

Defining & Classifying Psychological Disorders

Abnormal Psychology and Historical Approaches

Abnormal psychology is the scientific study of mental illness and maladaptive behavior. Throughout history, societies have developed various approaches to understanding and treating psychological disorders, often reflecting prevailing cultural and medical beliefs.

• Maladaptive behavior: Actions or tendencies that cause distress, impair daily functioning, or increase the risk of harm to oneself or others.

• Historical treatments included trepanation (drilling holes in the skull to release 'evil spirits') and the use of asylums for the mentally ill.

• The medical model treats psychological disorders as illnesses with specific symptoms, causes, and outcomes, similar to physical diseases.

• Emil Kraepelin contributed to the classification of psychoses and the development of early diagnostic manuals.

The Diagnostic and Statistical Manual of Mental Disorders (DSM)

The DSM is the primary classification system for psychological disorders in North America. It provides standardized criteria for diagnosis and has evolved over time to include a growing number of disorders.

• Current edition: DSM-5-TR (Text Revision).

• Disorders are now viewed on a severity spectrum (e.g., autism spectrum disorder).

• Recent additions include prolonged grief disorder.

• Challenges include subjective clinician bias, reliance on self-report, and the risk of stigma from diagnostic labels.

Applications of Diagnoses

Diagnoses in Society

Psychological diagnoses have important implications in various settings, including education and the legal system.

• Classrooms: Diagnoses such as ADHD (Attention Deficit/Hyperactivity Disorder) help identify children with persistent hyperactivity, impulsivity, and attention difficulties. There is ongoing debate about the increase in ADHD diagnoses and the influence of social media.

• Courtrooms: The "not guilty by reason of insanity" defense (M’Naghten rule) allows for mental disorder defenses in criminal cases.

Personality & Dissociative Disorders

Personality Disorders

Personality disorders are enduring patterns of behavior, cognition, and inner experience that deviate markedly from cultural expectations, are inflexible, and lead to distress or impairment.

• They are grouped into three clusters based on descriptive similarities: Cluster A (odd/eccentric), Cluster B (dramatic/emotional/erratic), and Cluster C (anxious/fearful/inhibited).

Cluster A: Odd or Eccentric Disorders

• Paranoid Personality Disorder: Persistent suspicion and mistrust of others, often interpreting their motives as malevolent. Associated with increased vigilance for threats.

• Schizoid Personality Disorder: Social detachment, limited emotional expression, and little interest in close relationships.

• Schizotypal Personality Disorder: Acute discomfort in close relationships, cognitive or perceptual distortions, and eccentric behavior. Linked to abnormalities in the superior temporal gyrus.

Cluster B: Dramatic, Emotional, or Erratic Disorders

• Borderline Personality Disorder (BPD): Instability in relationships, self-image, and emotions; impulsivity; intense fear of abandonment. Associated with medial frontal lobe activity.

• Narcissistic Personality Disorder (NPD): Grandiosity, need for admiration, lack of empathy, and vulnerability to criticism.

• Histrionic Personality Disorder: Excessive emotionality and attention-seeking behavior.

• Antisocial Personality Disorder (APD): Disregard for the rights of others, lack of empathy, impulsivity, and often criminal behavior. Resistant to treatment and associated with reduced frontal cortex activation and amygdala abnormalities.

Cluster C: Anxious or Fearful Disorders

• Avoidant Personality Disorder: Social inhibition, feelings of inadequacy, and hypersensitivity to negative evaluation.

• Dependent Personality Disorder: Excessive need to be taken care of, submissive and clinging behavior, and fears of separation.

• Obsessive-Compulsive Personality Disorder (OCPD): Preoccupation with orderliness, perfectionism, and control, distinct from obsessive-compulsive disorder (OCD).

Dissociative Disorders

Dissociative Identity Disorder (DID)

Dissociative disorders involve disruptions in consciousness, memory, identity, or perception. Dissociative Identity Disorder (DID) is characterized by the presence of two or more distinct personality states or identities, often as a coping mechanism for severe trauma, especially in childhood. DID remains controversial regarding its prevalence and etiology.

• Dissociation: A psychological state in which a person feels disconnected from their thoughts, feelings, memories, or sense of identity.

• Common experiences include feeling "in the zone" or as if events are unreal.

References: DSM-5, Yeung et al. (2022), and other academic sources as cited in the lecture.