Upload
alexia-reynolds
View
235
Download
0
Embed Size (px)
Citation preview
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 ~
NOT uncomplicated bereavement organic
Diagnosis 5 of 9 symptoms
not complete list duration > 2 weeks ~
Diagnosis & Symptoms
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 ~
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 ~
Other Selective Reuptake Inhibitors
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 ~