Depression

Question 1

What is mood disorder?

Answer 1

-When your general emotional state or mood is distorted or inconsistent with your circumstances and interferes with your ability to function.

• e.g SAD, Bipolar Disorder, etc…

Question 2

What is major depressive disorder(MDD)?

Answer 2

• Most common disorder
• Individuals experience persistent feelings of sadness and hopelessness and lose interest in activities they once enjoyed(can have physical symptoms such as chronic pain or digestive issues)

Question 3

What are some symptoms of major depressive disorder(MDD)?

Answer 3

• Five or more of these following symptoms must be present during the same 2 week period to be diagnosed.
• Diminished interest or pleasure in all activities.
  -Significant weight loss when not dieting or weight gain.
  -Insomnia or hypersomnia nearly everyday.
  -Fatigue or loss of energy.
• Diminished ability to concentrate or indecisiveness
  -Recurrent thoughts of death or suicide

Question 4

Why is there sex differences in depression?

Answer 4

• May reflect patterns for seeking help
  -Social discrimination
  -May have to do with sex difference in endocrine physiology(HPA axis or estrogens are influenced by cortisol)

Question 5

What is the prevalence for genetic links to depression?

Answer 5

-First degree relatives(e.g parents, siblings) of individuals have 2-3 time greater to have depression.
-If there is identical twins the, one identical twin has depression then the other twin has 45.6 % chance of having it as well.
- If there are fraternal twins, it is 20.2 % chance for other twin to get it.

Question 6

What was the originally thought way of getting depression?

Answer 6

• is thought to be strictly due to deficit in a monamine signalling.

Question 7

What is monoamine?

Answer 7

Neurotransmitters that contain one amino group connected to an aromatic ring by a two-carbon chain(e.g CH2-CH2)

Question 8

What does it mean by deficit in signalling?

Answer 8

• The limited release of NTs, deficits in ability to clear Nts in the synapse, limited receptors to bind to.

Question 9

What is the glucocorticoid hypothesis of depression?

Answer 9

• The glucocorticoid hypothesis suggests that dysfunctional regulation of the HPA axis stress response contributes to depression.

Question 10

What is the evidence for glucocorticoid hypothesis of depression?

Answer 10

• The most clinical findings
• Hypercortisolemia: Elevated levels of cortisol in the blood, even during non-stressful times. And chronic stress can lead to over secretion of cortisol.
• Impaired negative feedback of HPA axis: The brain is not able to respond to elevated blood cortisol by shutting down CRH, ACTH, and cortisol secretion.

Question 11

What happens to glucocorticoid receptors in Hippocampus?

Answer 11

-In the hippocampus it activates the negative feedback system and shut down the stress response. meaning people with depression cannot shut down their response easily, meaning theres is more damage to hippocampus.

Question 12

How does SSRIs work in the synapse?

Answer 12

-When released, excess serotonin is broken down by enzyme monoamine oxidase(MAO) and is cleared by serotonin reuptake transporters.
- SSRIs drugs like Prozac work by blocking serotonin reuptake transporters leading to an increase in the synapse.

Question 13

Why is estrogen protective against stress and depression?

Answer 13

• The negative feedback system is more efficient during the follicular phase, when estrogen is high.
  -Women show lower cortisol levels in response to social stress during follicular phase.
  -SSRIs antidepressants work better when combined with estrogen.

Only possible t understand stress response in females because of their different cycles

Question 14

What is psilocybin?

Answer 14

-Compound found in various species of fungi(e.g mushrooms)
-Inactive, but when ingested or absorbed it is immediately turned into psilocin which has hallucinogenic effects.

Question 15

What does psilocybin do?

Answer 15

-Suggests this compound(alongside other psychedelic) may reduce symptoms of depression.

Question 16

What do antidepressants do in the hippocampus?

Answer 16

Antidepressants in the hippocampus help increase the rate of neurogenesis in the hippocampus

Question 17

What is shown in the hippocampal region of those with depression?

Answer 17

Reductions in hippocampal volume in those with depression, a long term decrease in neurogenesis can explain this

Question 18

What is neurogenesis?

Answer 18

Neurogenesis is the growth of new neurons, this process is blocked by cortisol and cytokines like IL-1

Question 19

What are SSRIs and SNRIs and what do they do?

Answer 19

• SSRIs: Selective Serotonin Reuptake Inhibitors are antidepressants that block serotonin uptake at synapses
• SNRIs: Selective Noradrenigic Reuptake inhibitors are antidepressants that block the reuptake of noradrenaline at the synapses.

Question 20

What is the follicular phase characterized by?

Answer 20

High estrogen and low progesterone