MENTAL

Mental Disorders Overview

  • Clinically significant disturbances in cognition, emotion, or behavior (WHO, 2022).

Historical Perspectives

  • Psychiatry emerged as a specialty in the late 1800s.

  • Pre-1900s: mentally ill believed to be possessed; treatment included prayer and exorcism.

  • Asylums became warehouses for chronic illness; deinstitutionalization led to community-based services.

Current Understanding of Mental Illness

  • Pathogenesis understanding remains in infancy; multifactorial influences (genetic, environmental, neurodevelopmental).

  • Biologic vs. psychosocial perspectives on the causes of mental disorders.

Behavioral Anatomy of the Brain

  • Hippocampus: memory regulation.

  • Amygdala: emotional regulation including fear and aggression.

Role of Neuromediators

  • Acetylcholine: underactivity linked to Alzheimer’s.

  • Norepinephrine: underactivity linked to depression.

  • Dopamine: regulates thought and emotion; overactivity linked to schizophrenia.

  • GABA: implicated in anxiety disorders.

Schizophrenia

  • Affects 1% of the global population; symptoms divided into positive, negative, cognitive, and affective groupings.

  • Positive symptoms include hallucinations and delusions; negative symptoms include lack of motivation and blunted affect.

  • Pathophysiology theories include brain structure abnormalities and genetic predispositions.

Depressive Disorders

  • Leading cause of disability, characterized by sadness or loss of interest; subtypes include major depressive disorder and dysthymic disorder.

  • Treatment includes psychotherapy and pharmacotherapy (SSRIs, SNRIs).

Anxiety Disorders

  • Most prevalent psychiatric disorder affecting 10-12% of Canadians.

  • Manifestations include heightened fear response and physiological symptoms.

  • Types include panic disorders, phobias, and generalized anxiety disorder.

Substance Abuse & Addiction

  • Characterized by misuse of substances despite negative consequences; related to loss of control and cravings.

  • Etiology may involve genetic, psychological, and environmental factors.

  • Neurophysiology: substances affect the brain's reward pathways leading to dependence.