Schizophrenia Spectrum, Dissociative, Somatic, and Personality Disorders

Schizophrenia Spectrum, Dissociative, Somatic, and Personality Disorders

Schizophrenia Spectrum Disorders

Schizophrenia is a severe, chronic psychotic disorder characterized by profound disruptions in thinking, perception, emotional expression, and behavior. Symptoms are clinically divided into positive and negative clusters.

Positive Symptoms (Excesses or Distortions of Normal Functioning)

• Hallucinations: False sensory perceptions occurring without an external stimulus. Auditory hallucinations (typically hearing voices arguing or giving commands) are the most common form in schizophrenia.
• Delusions: False, fixed, irrational beliefs held with firm conviction despite clear contradictory evidence. Common types include:
  • Delusions of Persecution: Believing one is being spied on, plotted against, or targeted for harm.
  • Delusions of Grandeur: Believing one possesses special powers, immense wealth, or a divine mission.
  • Delusions of Reference: Believing neutral environmental events (e.g., a television news report) contain secret, direct messages intended specifically for them.
• Disorganized Speech and Thinking: Disruption of logical thought flow. Manifests as derailment (loose associations), tangentiality, or in extreme cases, word salad (incoherent jumbles of words).
• Catatonia: Marked motor abnormalities, ranging from catatonic stupor (immobility, waxy flexibility) to purposeless, agitated motor activity.

Negative Symptoms (Deficits or Losses of Normal Functioning)

• Flat Affect: Diminished or total absence of emotional expression in facial movements, voice tone, and gestures.
• Avolition: Severe lack of initiative, energy, or motivation to engage in goal-directed activities.
• Alogia: Poverty of speech, characterized by brief, empty responses.
• Anhedonia: Inability to experience pleasure from previously enjoyed activities.

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Etiology of Schizophrenia

• The Dopamine Hypothesis: Suggests schizophrenia is driven by hyperactive dopamine transmission in the brain. Specifically, excess dopamine binding at D2 receptors in the mesolimbic pathway produces positive symptoms (supported by the fact that classical antipsychotic drugs are D2 antagonists).
• Brain Structural Abnormalities: Neuroimaging consistently reveals enlarged lateral ventricles (fluid-filled cavities), reduced cortical gray matter volume, and reduced activity in the frontal lobes (hypofrontality).
• Genetic Concordance: Family and twin studies demonstrate a strong genetic component. Monozygotic (identical) twins exhibit approximately a 50% concordance rate for schizophrenia, compared to a ~10-15% concordance rate in dizygotic (fraternal) twins and a 1% risk in the general population.
• Environmental & Neurodevelopmental Factors: Prenatal exposure to influenza or viral infections, maternal malnutrition, birth complications causing hypoxia, and heavy adolescent cannabis use interact with genetic vulnerabilities.

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Dissociative Disorders

Dissociative disorders involve disruptions or breakdowns of memory, consciousness, identity, or perception of the environment.

• Dissociative Identity Disorder (DID): Formerly called Multiple Personality Disorder; characterized by the presence of two or more distinct personality states ("alters") that recurrently take control of behavior, accompanied by memory gaps for daily events and personal history.
• Dissociative Amnesia: Sudden inability to recall important personal information, usually of a traumatic or stressful nature, inconsistent with ordinary forgetting.
  • Dissociative Fugue: A specific subtype involving sudden, unexpected travel away from home accompanied by confusion about or adoption of a new identity.
• Depersonalization / Derealization Disorder: Persistent or recurrent feelings of detachment from one's own mental processes or body (depersonalization, feeling like an outside observer) or feeling that external surroundings are unreal, dreamlike, or distorted (derealization).

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Somatic Symptom and Related Disorders

These disorders involve prominent physical symptoms that cause significant distress and impairment, without a discernible biological basis.

• Somatic Symptom Disorder: Characterized by one or more physical symptoms accompanied by excessive, disproportionate thoughts, feelings, and anxiety regarding symptom seriousness.
• Illness Anxiety Disorder (formerly Hypochondriasis): Preoccupation with having or acquiring a serious, undiagnosed medical illness, with minimal or no physical symptoms present. Individuals perform excessive health-related checking behaviors.
• Conversion Disorder (Functional Neurological Symptom Disorder): Altered voluntary motor or sensory function (e.g., sudden blindness, paralysis, seizures, loss of hearing) that is structurally incompatible with known neurological or medical conditions. Often triggered by acute psychological stress or conflict. Historically associated with la belle indifférence (an unexpected lack of concern regarding the severe deficit).

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Feeding and Eating Disorders (DSM-5)

Eating disorders involve severe disturbances in eating behavior and body-weight/shape evaluation. CLEP expects recognition of the major DSM-5 feeding and eating disorders:

• Anorexia Nervosa: Restriction of energy intake leading to a significantly low body weight; intense fear of gaining weight; disturbed body-image perception or undue influence of weight/shape on self-evaluation. Subtypes include restricting and binge-eating/purging. Medical risks include amenorrhea (historically emphasized), bradycardia, bone loss, and highest mortality among psychiatric disorders.
• Bulimia Nervosa: Recurrent binge eating (large amount + sense of loss of control) followed by compensatory behaviors (self-induced vomiting, laxatives, fasting, or excessive exercise), occurring on average at least once weekly for 3 months. Body weight is often normal or above-normal—an important contrast with anorexia.
• Binge-Eating Disorder: Recurrent binge episodes without regular compensatory purging; associated with marked distress and often with obesity.
• Etiology Notes: Multifactorial—genetic vulnerability, sociocultural thin ideals, perfectionism, family dynamics, and serotonin dysregulation. Cognitive-behavioral therapy and (for bulimia/BED) SSRIs are common evidence-based treatments.

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Personality Disorders (DSM-5 Clusters)

A Personality Disorder is an enduring, inflexible, pervasive pattern of inner experience and behavior that deviates markedly from cultural expectations, begins by adolescence or early adulthood, and leads to distress or impairment. The DSM-5 categorizes ten personality disorders into three clusters:

Cluster A: Odd / Eccentric

• Paranoid Personality Disorder: Pervasive distrust and suspiciousness of others, interpreting motives as malevolent.
• Schizoid Personality Disorder: Social detachment and indifference to interpersonal relationships; restricted emotional range.
• Schizotypal Personality Disorder: Peculiarities of appearance, eccentric behavior, magical thinking, and acute discomfort in close relationships.

Cluster B: Dramatic / Erratic / Emotional

• Antisocial Personality Disorder (ASPD): Pervasive pattern of disregard for and violation of the rights of others, deceitfulness, impulsivity, aggressiveness, and profound lack of remorse. Must be at least 18 years old with a history of Conduct Disorder before age 15.
• Borderline Personality Disorder (BPD): Pervasive instability in interpersonal relationships, self-image, and affects; intense fear of abandonment; impulsivity; recurrent self-harm or suicidal gestures.
• Histrionic Personality Disorder: Excessive emotionality and attention-seeking behavior; uncomfortable when not the center of attention.
• Narcissistic Personality Disorder: Grandiose sense of self-importance, need for excessive admiration, sense of entitlement, and lack of empathy.

Cluster C: Anxious / Fearful

• Avoidant Personality Disorder: Social inhibition, extreme feelings of inadequacy, and hypersensitivity to negative evaluation or rejection.
• Dependent Personality Disorder: Submissive, clinging behavior driven by an excessive need to be taken care of, leading to fears of separation.
• Obsessive-Compulsive Personality Disorder (OCPD): Preoccupation with orderliness, perfectionism, and mental/interpersonal control at the expense of flexibility and efficiency. (Note: OCPD lacks the explicit intrusive obsessions and compulsions of OCD).

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DSM-5 Personality Disorder Cluster Summary