Transcript Chapter 22: Mental Illness

Bear: Neuroscience: Exploring the
Brain 3e
Chapter 22: Mental Illness
Slide 1
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
Introduction
Neurology
Branch of medicine concerned with the
diagnosis and treatment of nervous system
disorders
Neurological disorders
Help illustrate the role of physiological
processes in normal brain function
Slide 2
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
Introduction
Psychiatry
Branch of medicine concerned with the
diagnosis and treatment of disorders that
affect the mind or psyche
Psychiatric disorders
Examples: Anxiety disorders, affective
disorders, schizophrenia
Slide 3
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
Mental Illness and the Brain
Human behavior
Product of brain activity
Brain
Product of two mutually interacting factors
DNA
Determines individualism
Slide 4
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
Mental Illness and the Brain
Mental illness
Diagnosable disorder of thought, mood, or
behavior that causes distress or impaired
functioning
Earlier belief
Disorders of the body
Disorders of the mind
Slide 5
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
Mental Illness and the Brain
Psychosocial Approaches to Mental Illness
Freud’s theory: Mental illness- Unconscious
and conscious elements of psyche come
into conflict
Skinner: Many
behaviors are learned
responses to the
environment
Maladaptive behavior
Slide 6
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
Mental Illness and the Brain
Biological Approaches to Mental Illness
General paresis of the insane
Symptoms: Mania, cognitive deterioation
Cause: T. pallidum infection
Paul Ehrlich (1910)
Penicillin (1928)
Mental illnesses traced directly to
biological causes
Roots of mental disorders
Slide 7
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
Anxiety Disorders
Fear
An adaptive response to threatening
situations
Innate and species-specific
Learned
Anxiety disorders
Caused by inappropriate expression of fear
Slide 8
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
Anxiety Disorders
Common Anxiety Disorders
Panic disorder
Agoraphobia
Obsessive-compulsive disorder
Generalized anxiety disorder
Specific phobias
Social phobia
Post-traumatic stress disorder
Slide 9
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
Anxiety Disorders
Biological Bases of Anxiety Disorders
Fear evoked by threatening stimulus:
Stressor
Manifested by stress response
Stimulus-response relationship
strengthened (and weakened) by
experience
Stress: Corticotropin-releasing hormone
(CRH) adrenocorticotropic hormone
(ACTH) cortisol
Slide 10
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
Anxiety Disorders
Biological Bases of Anxiety Disorders (cont’d)
Stress Response
Slide 11
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
Anxiety Disorders
Regulation of the HPA Axis by the Amygdala
and Hippocampus
Both regulate CRH neurons
Amygdala projects to bed nucleus of the
stria terminalis, which activates the HPA
axis
Hippocampus deactivates the HPA axis
Glucocorticoid receptors
Feedback loop
Push-pull style regulation
Slide 12
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
Anxiety Disorders
Treatments for Anxiety Disorders
Psychotherapy
Anxiolytic Medications
Role of GABA
Benzodiazepines
Serotonin-selective reuptake inhibitors
(SSRIs)
Drug target: CRH receptors
Slide 13
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
Anxiety Disorders
A Description of Affective Disorders
“Mood” Disorders
Major Depression
Depression
Dysthymia
Bipolar Disorder
Manic-depressive disorder
Mania
Hypomania
Slide 14
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
Anxiety Disorders
Biological Bases of Affective Disorders
The Monoamine Hypothesis
Problems with diffuse modulatory
systems
Reserpine
Monoamine Oxidase (MAO)
Imipramine
Monoamine hypothesis of mood disorders
Slide 15
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
Anxiety Disorders
Biological Bases of Affective Disorders (cont’d)
The Diathesis-Stress Hypothesis
Genetic and nongenetic
Diathesis
HPA system
Impact of CRH
HPA function
Glucocorticoid receptor
Tactile stimulation process
Factors of mood and anxiety disorders
Slide 16
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
Anxiety Disorders
Treatments for Affective Disorders
Electroconvulsive Therapy (ECT): Localized
electrical stimulation
Advantage of ECT: Quick relief
Adverse effect of ECT: Prior memories,
storage of new information
Structures involved: Temporal lobe
Psychotherapy: Help patients overcome
negative views
Slide 17
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
Anxiety Disorders
Treatments for Affective Disorders (cont’d)
Antidepressants
Slide 18
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
Anxiety Disorders
Treatments for Affective Disorders
Lithium
Slide 19
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
Schizophrenia
A Description of Schizophrenia
Severe mental disorder
Symptoms of schizophrenia: Loss of contact
with reality
Three types of schizophrenia
Paranoid schizophrenia
Disorganized schizophrenia
Catatonic schizophrenia
Slide 20
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
Schizophrenia
Biological Bases of Schizophrenia
Genes and the Environment
Schizophrenia: A genetic disorder
Schizophrenia and the ventricle to-brainsize ratio
Other structural observation of the
brains of schizophrenics
The Dopamine Hypothesis: Psychotic
episodes in schizophrenia triggered by
activation of dopamine receptors
Neuroleptic drugs
Slide 21
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
Schizophrenia
Biological Bases of Schizophrenia (cont’d)
The Glutamate Hypothesis
Behavioral effects of phencyclidine
(PCP)
Introduced in1950s as an anesthetic
Inhibits NMDA receptors
Glutamate: Fast excitatory
neurotransmitter in the brain, two
important receptor subtypes, AMPA and
NMDA
Slide 22
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
Schizophrenia
Treatments for Schizophrenia
Consists of drug therapy combined with
psychosocial support
Conventional neuroleptics, such as
chlorpromazine and haloperidol, act at D2
receptors
Reduce the positive symptoms of
schizophrenia
Also have numerous side effects
NMDA receptor
Slide 23
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
Concluding Remarks
Impact of neuroscience on psychiatry
Mental illness
Chemical synaptic transmission is affected by
drugs
Genes and environment play an important
role
Environmental stresses may contribute to
schizophrenia
Appropriate sensory stimulation in early
childhood
Slide 24
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
End of Presentation
Slide 25
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins