PSY 241 Lecture 22

Depression
- sadness
- loss of interest in things
- slowed movement
Mania
- wild excitement
- racing thoughts
- exaggerated feeling of well-bring
Unipolar Depression
- Depression only and normal emotional states
- Dysthymia: less severe form of unipolar depression
Bipolar Disorder
- Depression and Mania
- Clyclothymia: less severe form of bipolar disorder
Genetics
- likelihood of developing disorder increases if related to someone who has a mood disorder
- rate of being diagnosed is higher if related to someone with bipolar disorder
- not a single gene has been implicated - multiple
- Genes may increase sensitivity to environmental stressors
Environmental factors - Seasonal Affective Disorder (SAD)
- depression and lethargy during winter months
- Light therapy needed
Sleep characteristic changes in affective disorders
Difficulty falling asleep & inability to maintain sleep
- EEG studies:striking reduction of stage 3 and increase in stages 1 & 2
- Patients enter REM sleep very quickly, with an increase of REM sleep in the first half of the night
- The length of time before REM sleep begins correlates with the severity of depression
Brain changes with Depression
- ↑ blood flow to frontal cortex + amygdala
- ↓ blood flow to parietal + posterior temporal cortex + anterior cingulate
- Cortex of right hemisphere is thinned
- Increased activity in right prefrontal cortex and decreased in left
Endocrine Dysfuntions
- ~45-60% depressed patients have neuroendocrine abnormalities
- Hyposecretion of Corticotropin Releasing Factor (CRF) + Cortisol (stress hormones)
- *Disruption of Hypothalamic-Pituitary-Adrenal Axis (HPA-axis)
Disruption in HPA Axis: ____________ levels of Cortisol in depressed patients compared to other psychiatric controls or normal controls

Higher levels of Cortisol in depressed patients compared to other psychiatric controls or normal controls
Dexamethasone

Synthetic glucocorticoid
Monoamine hypothesis of depression
Idea that depression is caused by decreased activity at noradrenergic and serotonergic synapses
- 5-HIAA (a serotonin metabolite) is lower in people with major depression
- Low levels of CSF 5-HIAA associated with suicide
- Norepinephrine metbolite (MHPG) lower in people with major depression
- As norepinephrine metabolites increase, subjects with bipolar disorder become manic
Low monoamine levels

increase depression
high monoamine levels

reduce depression
Actions of Antidepressants
- MAOIs blocks enzyme MAO
- prevent from breaking transmitters into inactive metabolites
- Tricyclic drugs and SSRIs block reuptake
Type of MAO-I

Iproniazid (Ipronid)
Type of Classic tricyclics - block serotonin and norepinephrine reuptake

Imipramine (Tofranil)
Type of Atypical antidepressants - selective norepinephrine reuptake inhibitors - SNRI

Duloxetin (Cymbalta)
Type of Norepinephrine reuptake inhibitor; Dopamine reuptake inhibitor

Bupropion (Wellbutrin)
Learned helplessnes

Decrease in serotonin function
Lithium Carbonate

Metallic ion - has been shown to be clinically effective in treating bipolar disorder
Ketamine (glutamate antagonist)

relief occurs 2 hours of administration
Deepr brain stimulation (DBS)
- through a surgically implanted electrode directed at cingulate cortex
- no control or placebo studies
- low Ns
Cognitive behavioral therapy (CBT)
- 20 sessions
- effective as SSRIs
Sleep deprivation
- Increase in Norepinephrine levels
- LC shuts down
Exercise

Increase adult hippocampal neurogenesis
Electric Convulsive Therapy
- Used for drug-resistant depression
- Mechanism of action is not clear
- Disadvantages
- High relapse rate
- Memory deficits

Author

ralejo

219883

Card Set

PSY 241 Lecture 22

Description

arturo zavala psychobiology mood disorders

Updated

2013-05-16T05:39:21Z

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