DEPRESSION Flashcards
What is depression
A state of low mood and aversion to activity that can affect a person’s thoughts and behaviour
Depressed people feel sad, anxious, empty, hopeless, helpless, worthless, guilty, irritable and
angry
note people with depression can also experience cognitive deficits
depression can be normal (reactive depression ) as long as it does not persist for a long or cause significant functional impairment
anhedonia
loss of ability to feel pleasure and is a common symptom of depressive disorders and substance use disorder.
the four main forms of depression and their descriptions
major or unipolar depression: involves at least five symptoms for a two-week period, and interferes with funtionality(eating, sleeping..etc)
reactive depression : depression occurs in response (as a way to cope) to an averse event.
persistent depressive disorder(dysthmia): presents with the same symptoms as major depression but it is less severe
bipolar disorder(manic depression) : mood cycle that shifts from severe highs (mania) or mild highs (hypomania) to severe lows (depression)
note there are 2 forms of bipolar disorder (I and II)
major depressive disorder is more prevalent in men than in women, true or false
false, it is more prevalent in women
median age at onset is about 32.5
mania refers to severe highs in mood
does bipolar disorder II ever develop into mania
no
rapid cycling bipolar disorder
is a type of bipolar disorder that involves having at least four mood episodes in a year. These episodes can be depressive, hypomanic, manic, or mixed.
in long lasting depression which parts of the brain are there decreased activities in
the prefrontal cortex
hippocampus
in long lasting depression which parts of the brain are there increased activity
amygdala
hypothalamus
neurogenesis
the process of creating new neurons in the brain
stress triggers both anxiety and depression , true or false
true
how does stress reduce neurogenesis
remeber the fact that stress triggers anxiety and depression, meaning those 2 can have the same effects on neurogenesis
it raises the cortisol levels, reducing Brain-derived neurotrophic factor (BDNF). This leads to reduction in neurogenesis
BDNF is a protein that plays a major role in depression. people presenting with depression has reduced levels of BDNF.
catatonia
a state in which someone is awake but does not seem to respond to other people and their environment. Catatonia can affect someone’s movement, speech and behaviour in many different ways.
sleep is speicifically affected if someone is depressed, true or false
true
describe the relationship between depression and inflammation
dont need to know this excessively but know it still just in case
Depression is associated with a chronic, low-grade inflammatory response and activation of cell-
mediated immunity, as well as activation of the compensatory anti-inflammatory reflex system.
It is similarly accompanied by increased oxidative and nitrosative stress (O&NS), which contribute
to neuro-progression of depression, which causes activation of cyclo-oxygenase-2 (COX-2) and inducible NO synthase (iNOS)
The activation of the COX-2 enzyme (a key player in inflammation) and inducible nitric oxide synthase (iNOS) contributes to increased production of ROS and RNS, which exacerbates oxidative and nitrosative stress, creating a vicious cycle of neuroinflammation and cellular damage in the brain
the immune cells of the brain are called?
microglia
describe the dopamine pathway and functions involved
Originates from the Ventral Tegmental Area (VTA)
Connects to areas like the Nucleus Accumbens, Frontal Cortex, and Substantia Nigra.
functions include;
being released during Reward and motivation
being released during Pleasure and euphoria
Motor function (fine-tuning movements)
Compulsion
describe the serotonin pathway and functions involved
Originates from the Raphe Nucleus.
Connects to areas like the Hippocampus and Frontal Cortex.
functions include being released during;
Mood regulation
Memory processing
Sleep
Cognition
name the brains monoaminergic neurotransmitters
what does the monoamine hypothesis in depression state
Serotonin (5-HT)
* Noradrenalin (NE)
* And/or dopamine (DA)
that Depression is due to functional deficiency of brain monoaminergic transmitters
note there are shortcomings with the monoamine hypothesis , many of them
do ampthetamine or cocaine have antidepressant actions?
no both do not
the precursor to serotonin is ?
the amino acid L-tryptophan ((Trp)). The body converts tryptophan into 5-hydroxytryptophan ((5-HTP)), which is then converted into serotonin.
the enzyme responsible for converting tryptophan to 5HT (serotonin) is called tryptophan hydroxylase (TPH); it catalyzes the first step in the serotonin synthesis pathway by hydroxylating tryptophan to 5-hydroxytryptophan (5-HTP) which is then further converted to serotonin by aromatic amino acid decarboxylase.
the role of serotonin in depression, and how this is corrected?
depression is linked to insufficient 5-HT neurotransmission in some brain regions
this is partially corrected by increasing the availabilty of L-tryptophan or by drugs acting at different sites of the synaptic machinery to either;
inhibit serotonin reuptake(SSRIs) or inhibit monoamine breakdown
how do we increase L-tryptophan levels in the body
consuming more Carbohydrate-rich food
leads to Increased secretion of insulin
leads to Facilitated uptake of most amino acids into peripheral tissues (muscle), but not of tryptophan
that leads to Increased proportion of tryptophan in the blood relative to other amino acids
therefore there is Less competition for large neutral-amino acid transporter → favored transport of tryptophan across the blood-brain barrier (BBB)
More tryptophan available to cells for serotonin synthesis
name some categories of food rich in tryptophan
meat like elk, pork, turkey…etc
seafood like lobster, king and queen crab, crayfish
vegetables like spinach…etc
treatment options for depression
Cognitive and Behavioural Therapy
Pharmacological treatments
Alternative treatments
