Chapter 15: Mood
Disorders and
Schizophrenia
4/23/2015
Lecture Outline
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Affective Disorders
Schizophrenia
Mood Disorders
Unipolar Mood Disorders
Major Depressive Disorder (MDD)
Dysthymic Disorder – not as severe
Bipolar Mood Disorders
Bipolar I
Bipolar II
Cyclothymic Disorder
Major Depressive Disorder
DSM-IV-TR criteria
Presence of at least one major depressive episode
No manic (or hypomanic) episodes
Five or more during a 2-week period
Depressed mood
Anhedonia
Decreased (or increased) appetite
Insomnia (or hypersomnia)
Psychomotor agitation (or retardation)
Fatigue
Feelings of worthlessness or guilt
Diminished ability to concentrate
Recurrent thoughts of death/suicidal ideation
MDD: A few notes…
Women: 2x as often as men
Uncommon in children
Within any given year, 5% of
US adults have clinically significant depression
Lifetime prevalence: 10%
Various duration and
triggers
MDD: Genes & The Environment
Moderate degree of
heritability
Linked to ↑ anxiety
disorders, ADD, substance abuse, OCD, bulimia, migraines, IBS, and other syndromes among relatives
Relatives of women with
early-onset depression have
↑ risk
MDD: Gene + Environment Interaction
5-HTT (Serotonin Transporter)
Short-short, short-long, long-long
Short form: reduced ability to produce
5-HT
5HTT & Stress
Short-short: high stress, ↑ risk of MDD
Long-long: stress does not significantly increase risk of depression
Gene + environment interaction
is key
Postpartum Depression
Estrogen levels gradually rise to
1000x during pregnancy
20% of women report some degree, but less than .1% enter severe, long-lasting depression
More common in women who were previously diagnosed with depression Treatment Options
Antidepressent
s
TricyclicsSSRIs
MAOIs
Atypical antidepressants Antidepressants
Tricyclics (example: Tofranil)
1950s
Non-addictive
Risk of overdose
Block transporter proteins that reabsorb 5-HT,
DA, NE
Prolong NTs in synaptic cleft (prolong stimulation of post-synaptic cell)
Block histamine receptors,
acetylcholine receptors, certain Na channels Highly effective, but replaced by SSRIs and newer antidepressants
Treatment-resistant depression
Antidepressants
SSRIs (example: Prozac, Zoloft, Paxil)
Similar to tricyclics (specific to 5-HT)
Milder side effects
Similar efficacy
Most widely prescribed
MAOIs (example: Nardil)
Block monoamine oxidase
Last line of treatment
“Cheese effect”- pay attention to diet
Atypical antidepressants
Example: Wellbutrin inhibits reuptake of dopamine, but not serotonin
Where do drugs come from?
Herbal Remedies
• No regulation by FDA
• Does not go through the screening process
• Less expensive; no prescription
• But no guarantee what you are getting
• St. John’s Wort
• “Nutritional Supplement”
• How does it work?
• Increases efficacy of liver enzyme that breaks down most medicines
•
Decreases effectiveness of other drugs (including birth control!) Antidepressants
Effectiveness
Not great, but they do work somewhat…
We don’t actually know!
SSRIs block reuptake of 5-HT; however, some studies show an increase in 5-HT turnover in depression
Time course: many people don’t experience relief until after weeks of taking the drug (though the drugs exert their effects on synapses within hours)
Mood elevation
Repairing damaged cortex and hippocampus?
Release of neurotrophins?
Electroconvulsive Therapy (ECT)
Schizophrenia, epilepsy
Current use
Informed consent; severe cases; strong suicidal tendencies
Every other day (2 weeks)
Muscle relaxants or anesthetics used to to minimize discomfort
Side effects: memory loss (unless the shock is limited to right hemisphere) Risk of relapse
Mechanism unknown; alters gene expression of neurotrophic factors, arachidonic acid, neurogenesis in the hippocampus Altered Sleep Patterns
Depressed
