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Mood Disorders
Lesson 24
Mood Disorders
Unipolar depression
 Mania
 Bipolar disorder
 Seasonal Affective Disorder (SAD) ~

Unipolar Depression
Extreme sadness & despair
 extent & duration important
 Prevalence
 females 9-26%
 males 5-12%


2:1 females ~
Unipolar Depression
endogenous vs. reactive
 Genetic component
 DZ twins  25% concordance
 MZ twins  70% concordance

Diagnosis & Symptoms
Disrupted eating & sleeping
 increased or decreased
 Impaired concentration
 Changes in activity
 increased or decreased
 Feelings of guilt / worthlessness
 Preoccupation w/ death or suicide ~

Diagnosis & Symptoms
NOT
 uncomplicated bereavement
 organic
 Diagnosis
 5 of 9 symptoms

not complete list

duration > 2 weeks ~
Treatment
Psychotherapy
 Drug Therapy
 Electroconvulsive-shock Therapy
 Sleep Deprivation
 Light Therapy ~

Etiology
Catecholamine hypothesis
 DA & NE
 deficiency
 Evidence from drug side effects
 Produce depression
 reserpine – monoamines
 propranalol - NE antagonist ~

Monoamine Hypothesis
Fluoxetine (Prozac)
 therapeutic effects
 blocks 5-HT reuptake
 5-HT modulates other NTs?
 usually more than one NT involved ~

Drug Treatment
Monoamine oxidase inhibitors – MAOIs
 NT not degraded
 more NT in synapse
 Cheese effect
 foods with tyramine
 metabolism  amphetamine-like
 risk of cerebral hemorrhage ~

Tricyclic Antidepressants
Indirect agonists
 block monoamine reuptake
 imipramine, desipramine
 Side effects
 Sympathetic arousal
 Possible overdose ~

SSRIs

Selective serotonin reuptake inhibitors
 Prozac (fluoxetine)




Zoloft (sertraline)
Paxil (paroxetine)
Luvox (fluvoxamine)
blocks 5-HT reuptake
 Less effect on NE & DA ~
SSRIs vs Tricyclics
Fewer side effects
 less danger of overdose
 As effective as tricyclics
 Neither addictive
 Animals don’t self-administer
 negative reinforcement ~

Criticisms
Immediate effects on NT level
 Therapeutic effects  2-4 weeks
 Explanation?
 Compensatory responses
 Autoreceptor desensitization ~

Tetracyclic Antidepressants
Block reuptake & autoreceptors
 Faster therapeutic effects?
 yes...
 but still a delay ~

Other Selective Reuptake Inhibitors
Norepinephrine Dopamine Reuptake
Inhibitor (NDRI)
 bupropion (Welbutrin)
 Also tx bipolar & Smoking cessation
(Zyban)
 Side fx
 less sexual dysfuntion than SSRI
 Insomnia
 seizures - 150 mg/dose limit
 no subjective euphoria, abuse ~

Other Selective Reuptake Inhibitors
Selective Serotonin Norepinephrine
Reuptake Inhibitor (SNRI)
 venlafaxine (Effexor)
 Serotonin-2 Antagonists/Reuptake
Inhibitors (SARI)
 Trazodone (Desyrel)
 5HT2 –R: autoreceptor
 Anxiety disorders, bulimia
 Off-label use of antidepressants
 wide variety of disorders ~

Electroconvulsive Therapy - ECT
Rapid effects - few days
 Indications
 drug therapy ineffective
 danger of suicide
 Risk of drug interactions
 Mechanisms unknown ~

Sleep Deprivation
Depression  Early & frequent REM
 Tricyclics inhibit REM
 REM deprivation
 gradual therapeutic effects
 Total sleep deprivation
 immediate therapeutic effects
 Mechanisms unknown ~

Mania & Bipolar
Mania Symptoms
 Euphoria
 grandiose plans
 reduced need for sleep
 high risk activities
 Bipolar Disorder
 Cycling between mania &
depression ~

Etiology

Induced by drugs
 Monoamine agonists
 cocaine, amphetamine,
antidepressants
 Mostly NE & DA ~
Treatment: Mania & Bipolar
Lithium most common
 Dangerous, but thresholds well
known
 Mechanism unknown
 affects almost all NTs
 Also
 Anticonvulsants
 atypical neuroleptics ~
