Class 10: Depression Flashcards
Define Mood Disorder
A disorder in which a person’s general emotional state or mood is distorted or inconsistent with circumstances and interferes with your ability to function
Define Major Depressive Disorder
Persistent feeling of sadness and hopelessness and loss of interest in activities once enjoyed.
What is the most common mood disorder?
Major Depressive Disorder
Does Major Depressive Disorder have physical symptoms? If so what are some examples
Chronic pain or digestive issues
How common is depression?
1 in 6 people are diagnosed with depression
What are the 8 diagnostic criteria for depression in the DSM-5?
- Persistent feelings of sadness
- Diminished ability to think or concentrate, or indecisiveness
- Loss of interests in activities
- Appetite or weight changes (more than 5% in. month)
- Fatigue or decreased energy
- Feeling of worthlessness or excessive inappropriate guilt
- Slowing down of thoughts and physical movement
- Recurrent thoughts of death or suicide
What are the 3 criteria to be diagnosed with major depressive disorder and for how long?
- Must show 5+ symptoms for a period of 2 weeks and one must be depressed mood or loss of interest or pleasure.
2 . Must NOT be due to direct physiological effects of a substance or medical condition - Must NOT be better explained by other psychiatric disorders
In which gender is depression more often diagnosed?
Female
Does depression increase or decrease with age (in adults)?
Decrease
How are the symptoms of MDD between men and women different?
Males have higher rates of irritability, anger and often feel more discouraged.
What are 3 different risk factors for MDD?
- Genetics
- Major life changes, trauma, or stress
- Certain physical illnesses or medications
What can cause increased rate of MDD in women?
Hormonal fluctuations: menstrual cycle, pregnancy, postpartum, miscarriage, pre & post menopause
What is the concordance rate between twins (identical and fraternal) in MDD?
Identical: 45.6%
Fraternal: 20.2%
What can the gene BDNF increase the chance of?
MDD
What chemical is this?
Dopamine
What chemical is this?
Norepinephrine
What chemical is this?
Serotonin(5-HT)
What was depression traditionally strictly thought to be?
A deficit in monoamine signaling
Define Monoamine
A NT that contains one amino group connected to an aromatic ring by a two-carbon chain (such as -CH2-CH2)
Define 4 examples of ‘deficit in signaling’
- Limited release of NTs,
- deficit in ability to clear NTs in synapse,
- limited receptors to bind to,
- low affinity,
- etc
What are three monoamines?
Dopamine, Norepinphrine, Serotonin
What is the monoamine hypothesis?
Depression is caused by alterations in the synaptic activity of 5-HT
What are two pieces of evidence of the monoamine hypothesis states?
- Monoamine oxidase inhibitors are effective antidepressants (in some individuals)
- Selective serotonin reuptake inhibitors (SSRIs) are effective antidepressants (in some individuals)
How do SSRI drugs help treat depression?
Blocking the serotonin reuptake transporters while allows more Serotonin to activate post-synaptic transporters
Do NTs work in isolation?
NO!
Does SSRI’s efficacy prove that the low NTs are responsible for depression?
No. Since lowering NTs in a non depressed person does not lead to depression and while the NTs recover in days, symptoms do not recover as quickly (could be months)
What 4 factors could be at play in MDD?
- NT imbalance
- Abnormal connections between important neuronal circuits (between PFC, hippocampus, etc)
- Dysfunctional neuroplasticity
- Stress/Glucocorticoid
Define the Glucocorticoid Hypothesis
Dysfunctional regulation of the HPA axis stress response contributes to depression
Define Hypercortisolemia
Elevated levels of cortisol in blood, even during non-stressful times.
What can cause hypercortisolemia?
Chronic stress during childhood can lead to oversecretion of cortisol, associated with depression in adulthood (45% of (over 2 year) depressed patients experience abuse or loss in childhood)
What is the effect of continued exposure to high levels of cortisol?
Further damages to hippocampus (meaning the longer you have depression the worse it gets)
What is the visual difference of cell density between a healthy hippocampus and depressed hippocampus?
Healthy hippocampus have a higher cell density.
What is the general relationship between total hippocampus volume by days of untreated depression?
Hippocampus volume decreases the longer depression is untreated.
How do antidepressants reverse damage to hippocampus?
Antidepressants can increase the rate of neurogenesis in the hippocampus
What is neurogenesis blocked by?
By cortisol and certain cytokines (IL-1)
What are the 5 facets of the Multi-faceted disease, depression?
- NTs
- Structural Correlates
- Neuroinflammation
- HPA Axis Dysfunction
- Neurogenesis and Neuroplasticity
Which mental illness could Ketamine potentially help?
Depression
What type of drug is Ketamine?
Dissociative Anesthetic
What are the effects of ketamine at low doses?
subject feels detached from their body, sensation of floating, dreamlike and euphoric state
What are the effects of ketamine at high doses?
Subjects lose all mental contact with their environment, despite eyes open
What does ketamine do for depression?
Inhibits GABA (which inhibits neurons) therefore strengthening of synaptic plasticity
