1. Neuroscience: Exploring the Brain, 3e
Chapter 22: Mental Illness

2. Mental Illness and the Brain
Diagnosable disorder of thought, mood, or behavior that causes distress or impaired functioning
Earlier belief
Disorders of the body
Disorders of the mind

3. Mental Illness and the Brain
Biological Approaches to Mental Illness
Infection-related disease e.g., ‘general paresis of the insane’
Symptoms: Mania, cognitive deterioration
Cause: T. pallidum infection
Penicillin (1928)
Mental illnesses traced directly to biological causes
Roots of mental disorders

4. Anxiety Disorders Fear An adaptive response to threatening situations
Innate and species-specific
Learned
Anxiety disorders
Characterized by inappropriate expression of fear

5. Anxiety Disorders Common Anxiety Disorders Panic disorder Agoraphobia
Obsessive-compulsive disorder
Generalized anxiety disorder
Specific phobias
Social phobia
Post-traumatic stress disorder

6. 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

7. Anxiety Disorders Biological Bases of Anxiety Disorders (cont’d)
Stress Response
Cortisol release & sympathetic activation

8. Role of Amygdala

9. 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

10. Stress response: negative feedback via hippocampus
Amygdala
Stress
Glucocorticoid (Cortisol) release
Adrenal glands
Hypothalmic CRF release
Pituitary, ACTH

11. Anxiety Disorders Treatments for Anxiety Disorders Psychotherapy
Anxiolytic Medications
Role of GABA
Benzodiazepines
Serotonin-selective reuptake inhibitors (SSRIs)
Drug target: CRH receptors (at hypothalamus)

12. Anxiety Disorders A Description of Affective Disorders
“Mood” Disorders
Depression
Major Depression
Dysthymia (less severe)
Bipolar Disorder
Manic-depressive disorder
Mania (type I) or hypomania (type II)

13. Anxiety Disorders Biological Bases of Affective Disorders
The Monoamine Hypothesis
Problems with diffuse modulatory systems
Reserpine (depletes MAs)
Monoamine Oxidase (MAO) inhib. (phenelzine)
Imipramine (reuptake inhib)
Monoamine hypothesis of mood disorders

14. Anxiety Disorders Biological Bases of Affective Disorders (cont’d)
The Diathesis-Stress Hypothesis
Genetic and nongenetic
Diathesis (predispositions)
HPA system- Convergence site; genetic and environ.
Impact of CRH on HPA function
Role of early experience in shaping stress response
Glucocorticoid receptors and influence of
Tactile stimulation in rats

15. Epigenetic imprinting: Stress response
Maternal care: Licking & grooming pups
Adult ‘memory’ of maternal care
5HT release
Hippocampus
Negative feedback
Chromatin remodeling
cAMP, PKA
(DeMethylation of NGFi binding site)
NGFi transcript. factor
Long-term up regulation of GC mRNA expression
Glucocorticoid receptors
Stress
Adrenal glands
Hypothalamic CRF release
Pituitary, ACTH
Glucocort. release

16. 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

17. Anxiety Disorders Treatments for Affective Disorders (cont’d)
Antidepressants

18. Anxiety Disorders
Treatments for Affective Disorders
Lithium

19. 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

20. Schizophrenia Biological Bases of Schizophrenia
Genes and the Environment
Schizophrenia: genetic predispositions
Schizophrenia and the ventricle to-brain-size ratio
Other structural differences of the brains of schizophrenics
The Dopamine Hypothesis: Psychotic episodes in schizophrenia triggered by activation of dopamine receptors
Neuroleptic drugs (e.g., chlorpromazine)

23. Schizophrenia Biological Bases of Schizophrenia (cont’d)
The Glutamate Hypothesis
Behavioral effects of phencyclidine (PCP)
Introduced in1950s as an anesthetic
‘Inhibits’ NMDA receptors (open-channel blocker)
Glutamate: Fast excitatory neurotransmitter in the brain, two important receptor subtypes, AMPA and NMDA

24. 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

25. Concluding Remarks Impact of neuroscience on psychiatry
Causes of mental illness still unclear, despite knowing
how 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

26. End of Presentation

27. Mental Illness and the Brain
Human behavior
Product of brain activity
Brain
Product of two mutually interacting factors
DNA
Determines individualism

28. 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

29. 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
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