PSY 301 1st Edition Lecture 23 Outline of Last Lecture I Genes II Dopamine Hypothesis III Multiple Neurotransmitters IV Prenatal Influences V Physiological Reactions to Stress VI Mood Disorders VII Clinical Depression Outline of Current Lecture I Bipolar Disorder II Mania III Hypomania IV Genetics and Mood Disorders V Neurotransmitters and Mood Disorders VI Brain Dysfunctions and Mood Disorders VII Environmental Factors and Mood Disorders Current Lecture Bipolar Disorder Lifetime prevalence rate 4 1 no gender difference 2 all cultural and ethnic group 3 all ages less common in kids 4 more in higher SES a probably a matter of diagnosis Bipolar I alternation of depression and mania or hypomania mania 1 elevated expansive mood 2 grandiose to delusions of grandeur 3 little sleep 4 racing thought 5 very talkative 6 risk taking 7 15 20 develop psychotic delusions or hallucinations hypomania shorter and less severe Patterns of episodes vary 1 can be as short as a few hours or as long as a few months 2 some alternate and some don t 3 some patients have many manic episodes and some have very few 4 some patients have mania and depression together mixed states a combination of symptoms of both simultaneously There is usually no external trigger 1 sometimes there are early warning indicators 2 stressful life experiences often precede episodes 60 of people with bipolar disorder are alcohol or drug abusers High risk of suicide 1 greater risk even than for depression 2 roughly 20 of bipolar patients commit suicide Genetics Mood Disorders High heritability 1 Concordance rates are higher for identical than for fraternal twins a depression identical 50 fraternal 20 b bipolar disorder identical 60 fraternal 12 2 Bipolar involves complex inheritance not a single gene 3 seem to be separate inheritance pathways for depression and bipolar a people with one of these disorders tend to have relative with that disorder but not with the other mood disorder 4 Kids adopted away from depressed or bipolar parents at higher risk a greater effect for bipolar Neurotransmitters Mood Disorders 3 critical neurotransmitters 1 norepinephrine 2 dopamine 3 serotonin Mechanism is unclear but involves more than just too little or too much of the neurotransmitters 1 in depression antidepressant drugs immediately increase the available NTs but clinical effects don t appear for several weeks 2 in bipolar the question pattern of cycling seems unconnected to neurotransmitter levels People are more vulnerable to mood disorders if they have the variant of the short allele for the serotonin transporter gene Brain Dysfunctions Mood Disorders Depression 1 associated with heightened activity in the subgenual cingulate cortex part of the limbic system 2 low levels of brain activity in the left prefrontal cortex 3 enter REM sleep more quickly and spend more time there Bipolar Disorder 1 greater amygdala volumes 2 greater brain activity in subcortical emotionamygdala generative brain regions such as the Environmental Factors and Mood Disorders Environmental factors in depression 1 families with high levels of expressed negative emotions a predicts onset and relapse rates 2 more negative life events as kids 3 severe stressors in the 6 9 months prior to depression a one third of these reflect genetic tendencies 4 lack of intimate relationships especially for women Environmental factors in bipolar disorders 1 high life stress predicts higher relapse rates to high risk behavior and longer recovery times
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