Depression & bipolar (done) Flashcards
What is depression?
- More than simply feeling unhappy or fed up for a few days
- Patients persistently feel sad for weeks or months
- Real illness w underlying neurobiology
What is bipolar disorder?
A mental health condition that affects moods, which can swing from one extreme to another
Used to be known as manci depression
Symptoms depend on which mood patient is currently experiencing - each extreme can last for several weeks
What are the episodes that ppl with bipolar disorder suffer from?
- Depression
- Mania - feeling very high & overactive
What are the 2 symtoms that must be expereinced in depression?
At least 1 of these 2 to be diagnosed:
- Depressed mood
- Loss of interest of pleasure
What are the 9 symptoms of depression in the DSM-V?
- Depressed mood
- Loss of interest or pleasure
- Change in weight or appetite
- Insomnia or hypersomnia
- Psychomotor retardation or agitation
- Loss of energy or fatigue
- Feeling of worthlessness or guilt
- Impaired concentration or indecisiveness
- Suicidal ideation / suicide attempt
How many of the 9 symptoms of depression listed int he DSM-V are required for depression diagnosis?
At least 5 of 9
What is the main requirement to be diagnosed with bipolar disorder?
Subgroups all include manic episode:
Abnormally & persistently elevated/irritable mood lasting at least a week & present most of the day nearly every day
& at least 3 of the 7 symptoms listed in DSM-V
What are the 7 symptoms for bipolar disorder listed in the DSM-V?
- Inflated self esteem & grandiosity
- More talkative than usual or pressure to keep tlaking
- Dec need for sleep
- Flight of ideas or subjective experience that thoughts are racing
- Distractability
- Increase in goal-directed activity
- Excessive involvement in activities w high potential for painful concequences
Who made the monoamine hypothesis of depression?
Schildkraut - 1965
What were the 2 main parts of the monamine hypothesis?
1 –> Depression due to functional DEFICIT of MOA tranmitters & mania due to funtional EXCESS
2 –>
Drugs that ince MOA neurotransmission inc mood
Drugs that dec MOA neurotransmission dec mood
What are the drugs that inc MOA neurotransmission to inc mood in the MOA hypothesis?
- Tricyclic antidepressants (TCAs) that blcok reuptake
- MOA oxidase inhibitors (MAOI) that inhibit metabolism
What are the drugs that dec MOA neurotransmission to dec mood in the MOA hypothesis?
- Reserpine, alpha-methyltyrosine & methyldopa that inhibit synthesis or storage
What are the shortcoming sof the MOA hypothesis of depression?
- Doesn’t clarify pathophysiology of depression
- Doesn’t explain delayed theraputic onset or treatment-resistance
- Drugs like cocaine & amphetamine enhance MOA neurotransmission, but aren’t antidepressant
- Some clinically effective antidepressants don’t affect MOAs
Give examples of delayed theraputic onset or treamtent resistance (a shortcoming) in the MOA hypothesis?
- SSRIs elevate synpatic 5-HT within hours (& side effects appear)
- Antidepressant effects take ~3 weeks & don’t occur in 30% of cases
What are the 3 other explanations for depression other than MOAs?
- HPA axis
- Neuroplasticity & neurogenesis
- Inflammation
What is the HPA axis like in depressed patients?
They display HPA hyperactivation
This means they have impaired -ive feedback
What symptoms does HPA hyperactivity in depressed patients cause?
- Inc cortisol in saliva, plasma & urine
- Inc CRH in CSF & limbic brain regions
- Inc size & activity of the pituitary & adrenal glands
How do antidepressants work on the HPA axis?
They enhance negative feedback to dec HPA axis hyperactivity
(Correct the overactivity in HPA - not so much cortisol being produced)
How does hippocampal volume change in depression patients?
Hippocampal volume dec by ~10% in depression
What are the 2 explanations of dec hippocampal volume in depression patients?
- Neuroplasticity hypothesis
- Neurogenesis hypothesis
What is the neuroplasticity hypothesis?
Atrophy of mature neurons (shortened dendrites, dec spine density)
Neuronal connectivity decreases
What is the neurogenesis hypothesis?
Dec adult neurogenesis leads to dec new neurons & neural precursors
(No atrophy, formation of new neurons inhibited)
What supports the neuroplasticity & neurogenesis hypotheses?
Both are supported by pharmacological evidence:
Ketamine (rapid onset antidepressant)
–> inc no. & fucntion of spines in PFC
–> Many antidepressants inc adult neurogenesis
Why are ketmaine studies good support fromt eh neurplasticity & neurogenesis hypothesis?
Ketmaine acts on glutamate receptors - not MAOs
What are examples inflammatory markers?
Cytokines, chemokines & acute-phase proteinsW
What are inflammatory marker levels like in depression?
Patients w depression have inc inflammatory markers