Mood Disorders Lesson 25 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 but still a delay ~ Other Selective Reuptake Inhibitors Norepinephrine Dopamine Reuptake Inhibitor (NDRI) bupropion (Welbutrin) Also tx bipolar & Smoking cessation (Zyban) Selective Serotonin Norepinephrine Reuptake Inhibitor (SNRI) Serotonin-2 Antagonists/Reuptake Inhibitors (SARI) Off-label use of antidepressants wide variety of disorders ~ 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 ~