Depression Flashcards
1
Q
What is Psychiatry?
A
- Branch of medicine, diagnosis & treatment of disorders that affect the mind or psyche
- Disorder of thought, moods and fears considered outside the reach of neuroscience
- Now hope that neuroscience will help identify causes and treatment of mental illnesses (Anxiety, scz, depression)
2
Q
What do you think of mental illness and the brain?
A
- Human behaviour is the product of the brains activity
- The brain is the product of genetics and environment
- Experience
- Genetic make-up and experience can interact, making a person more or less susceptible to future experience
3
Q
Give some facts about mental illnesses
A
- In 2020, estimated about 971 mil ppl living with mental or behavioural disorders
- 1 in 4 British adults experience at least one diagnosable mental health problem in any year
- Depression affects 1 in 5 older people living in the community
- More than 70% of prison population has two or more mental health disorders
4
Q
Describe the characteristics of affective disoders
A
- Disorders of mood rather than thought/cognition
- Most common is depression
- Major cause of premature death and disability
5
Q
List the 2 different types of depression
A
- Unipolar Depression
- Bipolar depression
6
Q
Describe unipolar depression
A
- Mood swings in one direction
- Most common depressive illness
- 75% cases REACTIVE (induced by environmental factors)
- 25% cases are ENDOGENOUS (genes)
7
Q
Describe Bipolar depression
A
- Oscillation between depression and mania
- Mania: Excessive exuberance, enthusiasm, self confidence
- Type 1: More mania episodes with or without depression
- Type 2: Hypomania and always episodes of major depression (0.6%)
- Onset usually in adult life
- Strong hereditary tendency (no genes found yet)
8
Q
What is the criteria for being diagnosed with depression?
A
- Depressed mood most of the day, nearly everyday
- Markedly diminished interest or pleasure in all, or almost all activities most of the day
- Significant weight loss when not dieting or weight gain or decrease/increase in appetite nearly everyday
- A slowing down of thought and a reduction of physical movement
- Fatigue or loss of energy nearly everyday
- Feelings of worthlessness or excessive or inappropriate guilt nearly everyday
- Dimished ability to think or concentrate or indecisiveness
9
Q
What is required in order to be diagnosed with depression?
A
- 5 or more of the following symptoms have to be present during the same 2 week period and represent a change from the previous functioning
- Atleast one of the symptoms being a depressive mood or loss of interest
10
Q
What can the symptoms of depression be split into?
A
- Emotional symptoms
- Biological symptoms
11
Q
List some biological symptoms of depression
A
- Loss of appetite
- Loss of sleep
- Loss of libido
- Reduced activity
12
Q
List some Emotional symptoms of depression
A
- Apathy, Negativity
- Low self esteem, feeling guilty
- Loss of motivation
- Indecisiveness
13
Q
What are the other medical conditions that can coincide with depression (Co-morbidity)?
A
- Terminal illness
- Chronic illness
- Thyroid dysfunction
- Stroke
- Drug abuse
- Parkinson’s disease
- Anxiety
14
Q
What is the monoamine theory of depression?
Discuss evidences for the theory
A
Evidence for
- Overall reduced activity of central noradrenergic and/or serotonergic systems
- Reserpine depletes brain of NA and 5 HT induces depression
- Main antidepressants drugs (amines) in brain
15
Q
What is the monoamine theory of depression?
Discuss evidences against the theory
A
- Difficult to show deficits in the brain (NA) & (5-HT) and functioning results from CSF, plasma in depressed individuals respond better to one AD than another
- Most antidepressant drugs take several weeks for therapeutic effect but ã in amines acute
- Some antidepressants weak/no effect on amine uptake/ no increase in 5HT or NA but antidepressants
- Cocaine blocks amine uptake but has no antidepressant effect
- Decrease in 5HT in dipolar linked to aggression rather than depression
16
Q
What is the neuron doctrine theory of depression?
A
- NAergic & 5HT neurons input to hypothalamus
- Hypothalamus releases corticotropin releasing hormone
- CRH acts on pituitary, release of adrenocorticotrophic hormone
- Cortisol release from adrenal cortex in response to ACTH in blood
17
Q
What is the evidence for the neuron doctrine theory of depression?*
A
- There is evidence of hyperactivity of HPA in depressed patients
- Corticol plasma in depressed patients
- [CRH] I’m the cerebrospinal fluid
- There is clear evidence that genes and environment can contribute to this hyperactivity and as such could offer an explanation for how genes x environment interaction can predispose ppl to mental health conditions
18
Q
Describe the neuroendocrine in more detail
A
- ‘d hippocampal feedback in depression
- ’d glucocorticoid receptors (cortisol receptors) in hippocampus
- Glucocorticoid receptor gene expression regulated by early experience
- Tactile stimulation just after birth activates 5-HT pathways to hippocampus
- 5-HT triggers long-lasting in expression of glucocorticoid receptor gene
- in glucocorticoid receptors in hippocampus
- SSRIs glucocorticoid receptors in the hippocampus
19
Q
Describe the neuroplasticity & neurogenesis theory of depression
A
- Evidence of neuronal loss and neuronal activity in hippocampus and prefrontal cortex (decision making centres)
- Antidepressants and electroconvulsive therapy (ECT) promote neurogenesis in these regions
- 5-HT promotes neurogenesis during development (BDNF)
- Increase in Glutamate in Cx of depressed people (NMDA antagonists potential for depression treatment e.g. ketamine)
20
Q
Describe the brain activity in depressed patients
A
Depressed patients tend to have lower levels of activity’s in all areas of the brain
21
Q
List and describe the different types of treatments for Depression
A
- Cognitive behavioural therapy (CBT): Based on helping depressed individuals to recognise and change their negative cognitive processes and thus improve their mood & their counterproductive behaviours
- Pharmacotherapy: Assumes that depression is multi factorial but that interpersonal difficulties play a central role in maintaining depressive symptoms
22
Q
List some pharmacological treatment
A
- Tricyclic antidepressants
- Monoamine oxidase inhibitors
- Selective serotonin reuptake inhibitors
23
Q
Describe the use of SSRI’s
A
- NICE recommends SSRI’s for the pharmacological treatment of depression
- Selectively inhibit the reuptake of serotonin in the synapse
- Because they’re more selective in the molecules to which they bind, they do not bind to receptors on other classes of neurons
24
Q
List some long term neurochemical antidepressants
A
- Monoamine Oxidase inhibitors (MAOIs)
- Tricyclic Antidepressant Drugs (TCAs)
- Selective Serotonin Re-uptake Inhibitors (SSRIs)
- Other mixed 5HT/NA reuptake inhibitors (SNRIs)
- NA reuptake inhibitors
- Monoamine receptor antagonists
- Downregulation a2, 5HT1A, b1, b2, 5HT2A, 5HT3
25
Q
Describe the mechanism of action of MAOI’s
A
- Inhibition of MAO A correlates with anti depressive activity
- MAO-A 5-HT > Na
- MAOIs rapidly increase [5HT] > [Na] > [DA]
- Increase in Na -> increased Euphoria -> increase motor activity
26
Q
Describe MAO I
A
- Associated with food and drug interactions
- Tyramine acts as indirect sympathomimetic and increase Na release
- Excess Na destroyed by MAO, if blocked then Na will accumulate
- Na accumulation increases headaches, intracranial haemorrhage-> elevation in BP -> severe hypertension
- MAOI’s not specific, reduce metabolism of opioid analgesics and alcohol
27
Q
Describe Reversible MAOI’s (RIMA)
A
- One example is moclobemide
- Accumulation of NA displaces the RIMA allowing degradation of excess NA
- RIMAs sager and selective RIMAs better tolerated
28
Q
What is a side effect of MAOI’s?
A
- MAO is inhibited in the gut
- Dietry amines such as tyramine can get into the circulation
- Foods include cheese,yoghurt,meat,wine,yeast products
- All contain high concentrations of tyramine
- Tyramine acts as an indirect sympathomimetic displacing noradrenaline from vesicles
29
Q
Describe the mechanism of action of Tricyclic antidepressants
A
- Main therapeutic affects are: Na reuptake inhibitor, 5HT reuptake inhibitor
- Initially increase [NA] & [5HT] in synaptic cleft
- Chronic treatment down regulation of (B1) & 5HT2
- ⍺2, 5-HT1A/1D (autoR)
- Also affect mACh, HR, 5HTR
