Lec 72 Mood Disorders Flashcards Preview

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Flashcards in Lec 72 Mood Disorders Deck (28)
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What are DSM diagnostic criteria for major depressive disorder?

must have depressed mood OR anhedonia
must cause significant distress or impairment and there has never been manic episode
5 or more of the following for > 2 wks
- depressed mood
- anhedonia = lack of interest
- sleep disturbance = in/hypersomnia
- change in appetite
- low energy
- psychomotor agitation or retardation
- impaired concentration
- guilty feeling/self blame
- suicidal/thoughts of death


What is prevalence of major depressive disorder [MDD]?

~15% across different populations
more in women [1 in 4] than men [1 in 8]
pre-pubertal = equal men to women


What is course of MDD?

- may be triggered by event or may have no trigger
- untreated episode lasts 6-13 mo
- treated lasts 3 mo
- chronic with relapses


What percent of untreated MDD attempt suicide?



What are the 4 theories of depression etiology?

- psychodynamic
- cognitive
- neurobiological
- genetics


What is the psychodynamic theory of MDD?

by freud
- depression linked to real or imagined loss of a loved object and resulting damaged self esteem and unresolved conflict
- can be seen as anger turned inward

goal of treatment = promote symptom relief and personality change through understanding of unconscious conlifcts


What is the cognitive theory of depression?

by Aaron beck
- depression from specific cognitive distortions
- cognitive triad
---- negative views of self
---- negative views of environment
---- negative views of future


What are the neurobiological theories of MDD?

many theories from molecular and cellular level to whole brain imaging/neuro circuitry level

- MOA [DA/5HT/NE] deficiency
- glutamate dysregulation [excess glu]
- neuroendocrine [HPA] dysregulation
- structural and functional brain changes
- neuropathological changes
- impairments in neuroplasticity


What is the MOA deficiency hypothesis of depression?

depression is result of deficiecny of MOAs [5HT, DA, NE]

proof: early antidepressants blocked reuptake or degradation 5HT/NE
reality: its a more complicated picture


What is the AA NT system dysregulation theory of depression?

- chronic stress --> excess glutamate
- hyperactivation of NMDA glu receptors --> atrophy and death of neurons/glial cells

treat by ketamine = NMDA antagonist


What is the neuroendocrine dysregulation theory of depression?

- increased cortisol, CRF
- lack of normal cortisol suppression when given dexamethasone suppression test [DST]
- less negative feedback sensitivity
- less glucocorticoid receptor sensitivity
- hippocampus damaged

problem with this theory = no evidence of HPA dysfunction in many pts

hypercholesterolemia may be associated with very severe depression only


What are structural and functional brain changes thought to cause depression?

reduced volume in all the following areas plus:
reduced activity in:
- dlPFC = decision making, judgement
- ACC = motivation, reward, empathy

increased activity in:
- OFC = socially appropriate behavior
- amygdala = memory of emotional events

dlPFC + hippo = cognitive aspects of depression

lack of cortical regulation of limbic system


What neuropathological changes associated with depression?

- reduction glial cell density + number [maybe due to glu toxicity from stress]


What impairments in neuroplasticity associated with depression?

- decrease neurotropic factors
- subsequent failure of neuronal plasticity

decreased BDNF in depressive; inverse correlation level of BDNF and sensitivity to stress in healthy people


What is role of brain derived neurotrophic factor [BDNF]?

imp for axonal growth, neuronal survival, allowing changes in synapses between neurons throughout life

levels of BDNF affected by stress and cortical


What is the final common path for all effective therapies?

enhancement in neural plasticity and cellular resilience


What are genetics of depression?

- heritability
- no single depression gene = multiple genes combined with environmental causes


What is the gene/environment interaction of 5HT transporter gene in depression?

carriers of short allele of 5HT transporter gene can make vulnerable to depression under stress


What is treatment for MDD?

medications like SSRIs, tricyclic antidepressants, MOA inhibitors
ECT therapy
vagal nerve stimulation


What are diagnostic criteria for manic episode?

- at least 1 wk abnormally and persistently elevated mood PLUS
3-4 of:
- inflated self esteem/grandiosity
- decreased need for sleep
- more talkative
- flighty ideas
- distractibility
- psychomotr agitation
- psychotic/impaired functioning
- excessive involvement in pleasurable activities with high potential for painful consequence


What are diagnostic criteria bipolar 1 disorder?

- at least 1 manic episode

typically have recurrent episodes both mania/hypomania and depression but not required for diagnosis


What is the prevalence of bipolar 1 disorder?

equal in men/women
mean age onset = 18-21 yrs


What is course of bipolar disorder?

most have manias + depressions --> 10-20% ONLY manias
long term --> 15% well; 45% well but multiple relapses

more than 90% of individuals who have a single manic episode go on the have recurrent episodes


What is the neurobiology of bipolar disorder?

- dysregulation in limbic and prefrontal cortical circuitry
- HPA axis dysregulation
- decreased neuronal size and density


What are genetics of bipolar disorder?

8-10x increased risk in 1st degree relatives of bipolar; also 2-10x increase of MDD in 1st degree relatives of bipolar

65% heritability [compared to MDD 30%]
no one gene identified


What is epidemiology fo suicide?

10th leading cause of death in americans
highest in men older than 75
3rd leading cause of death age 15-24

almost all who kil themselves have diagnosable mental disorder; approx 2/3 of those who complete have seen a physician within a month of death


What are risk factors of suicide?

- family history
- demographics [older white male]
- previous suicide attempt
- psych disorders [esp MDD]
- substance abuse
- hopelessness
- impulsive or aggressive tendencies
- isolation [divorced, few friends]
- barriers to accessing treatment


What are protective factors for suicide?

- good clinical care
- easy access to clinical interventions
- connectedness
- skills in problem solving
- children