L4/L5 Major depressive disorder Flashcards
What is the difference between Incidence and Prevalence when we try to talk about the epidemiology of a disease?
Incidence: newly diagnosed cases of the disease
Prevalence: actual number of cases alive with the disease
What factor is a strong determinant of the likelihood of recovery for MDD?
Recency of onset
Many individuals who have been depressed only for several months can be expected to recover spontaneously, correct or not?
Corrct
Recovery likelihood is poor in the presence of late age of onset, true or false?
False; Recovery likelihood is poor in the presence of advanced age of onset
What are the diagnostic criteria now based on
Diagnostic and statistical manual of mental disorders 5th edition (DSM-5)
Five or more symptoms during the same 2-week period and at least one of the symptoms should be either of which two subtype?
(1) depressed mood
(2) loss of interest or pleasure
List the symptoms of the depressed mood subtype
(1) Depressed mood most of the day, nearly every day
(2) Significant weight loss when not dieting or decrease in appetite nearly every day (A change of more than 5% of body weight in a month)
(3) Hypersomnia nearly every day
(4) Psychomotor agitation or retardation nearly every day (observable by others, not merely subjective feelings of restlessness or being slowed down)
(5) Fatigue or loss of energy nearly every day
List the symptoms of the loss of interest or pleasure subtype
(1) Markedly diminished interest or pleasure in all, or almost all, activities most of the day, nearly every day
(2) Significant weight gain when not dieting or increase in appetite nearly every day. (A change of more than 5% of body weight in a month)
(3) Insomnia nearly every day
(4) Feelings of worthlessness or excessive or inappropriate guilt nearly every day
(5) Diminished ability to think or concentrate, or indecisiveness, nearly every day
(6) Recurrent thoughts of death, recurrent suicidal ideation without a specific plan, or a suicide attempt or a specific plan for committing suicide
What are the purposes of subtyping?
(1) Differentiating large group of patients
(2) Predicting treatment effectiveness
From different perspectives, what subtype models can we generate?
(1) Symptom-based subtypes
(2) Aetiologically-based subtypes
(3) Time of onset-based subtypes
(4) Gender-based subtypes
Biotypes of MDD overlapped with which mental disorder but not with which mental disorder?
Overlap with general anxiety disorder (GAD) but not schizophrenia
The heritability of MDD is really high, true or false?
False
The heritability is moderate (0.3-0.5)
By using which technique can we get the conclusion that MDD is highly polygenic?
genome-wide association studies (GWAS)
What does the monoamine theory proposes?
Serotonin, norepinephrine and dopamine deficiencies are responsible for the occurrence of depressive symptoms
In MDD, serotonin level is higher or lower?
Lower
In MDD, serotonin receptor activity is higher or lower?
Lower
In MDD, serotonin transporter activity is higher or lower?
Higher
Here the transporter means reuptake transporter
Briefly introduce the neuroplasticity hypothesis of MDD.
Stress and other negative stimuli induce changes in neural plasticity plays a significant role in the onset and development of depression
The evidence of animal model studies demonstrating that depressive-like behaviors are associated with alterations in cortical glutamate support which hypothesis of MDD?
The neuroplasticity hypothesis of MDD
Psychological Factor for MDD
(1) Neuroticism
(2) Adverse childhood experience
(3) Stressful life event
Genetic Factor for MDD
(1) 30-50% heritability from twins & adoption study
(2) polygenic
Serotonin Hypothesis:
How does serotonin work as a neurotransmitter? Describe the steps.
(1) Tryptophan obtained from daily diet
(2) Tryptophan → Serotonin (=5HT)
(3) Serotonin Stored in the vesicle
(4) When pre-synaptic neuron reaches activation potential, serotonin is released to postsynaptic neuron
Serotonin Hypothesis:
Based on this mechanism, what are the evidence on MDD patients that support this theory?
(1) tryptophan depletion
(2) low serotonin & its metabolite 5-HIAA level
(3) lower activity receptor on post-synaptic neuron
(4) higher activity & gene (relate to stress) for reuptake transporter → so there is less successful synaptic communication
Predominantly limbic connectivity features are correlated with what MDD symptoms?
Anxiety and insomnia
What are the two dimensions when subtyping patients to different clusters?
Anhedonia-related connectivity and Anxiety-related connectivity
According to studies related to neuroplasticity hypothesis, what metabolites in the medial frontal cortex are linked with depression?
Glutamatergic metabolites
According to neuroplasticity hypothesis, only single region and single pathway is involved or are there many of them?
Many of them are involved
Brain regions: hippocampus, prefrontal cortex, amygdala
Pathways: glutamate and glucocorticoid signaling pathways
According to neuroplasticity hypothesis, disruption of hippocampal function (including its capacity for neuroplasticity) lead to what?
(1) Anhedonia (because hippocampus regulates nucleus accumbens and the ventral tegmental area)
(2) Deficits in concentration and memory
(3) Dysregulation of the HPA axis stress response
Give a brief definition for schema
Internally stored representations of stimuli, ideas or experiences
What are the 3 features of depressive schema characterized by negative self-referential beliefs?
Unlovability
Hopelessness
Worthlessness
What is Beck’s cognitive traid for faulty information processing?
negative views about self, world and future
According to cognitive model of depression, three process are biased, what are they?
Biased attention, biased processing and biased memory
The biased memory is restricted to which kind of memory?
Explicit memory
What is the test used for testing biased attention?
eye-tracking
What is early attentional engagement?
latency/location/duration of inital fixation
What is the feature for MDD patients in eye-tracking tasks compared with controlled group?
(1) no differences in early attentional engagement
(2) longer maintenance in negative stimuli
(3) moderate decrease on positive stimuli
(4) attentional disengagement
For biased memory, is there any memory bias if the participants are asked to count letters in emotional words (encoding) and complete word stem/fragments (recall)?
no
What is interpretation bias for MDD?
create more negative, fewer positive meaning to explain ambiguous information
What is the test used for testing interpretation bias?
Scrambled sentence test (SST)
What is the test used for testing self-referential processing bias?
Self-referential encoding task
If a person stuck in rumination, is he/she going to take action?
No
Which part of Anterior cingulate cortex (ACC) is cognitive and which part is affective?
Dorsal ACC = cognitive
Ventral ACC = affective
What does valence identification mean?
Identification of positive/ neutral/ negative words
Give examples of dorsal ACC’s cognitive functions
(1) Conflict-monitoring
(2) Response-selection and execution
Give examples of ventral ACC’s affective functions
(1) Emotion assessment
(2) Emotion related learning
(3) Autonomic regulation (related to autonomical nervous system)
Dorsal ACC relays which type of cognitive inputs, top-down or bottom-up?
Top-down
Which part of ACC integrates emotional feedback from the limbic system (e.g. amygdala) and projects to higher-order cognitive structures (e.g. dlPFC)?
Subgenual ACC (sgACC)
Resting state sgACC functional connectivity with which brain network was significantly greater in the depressed subjects compared to the control group?
Default-mode network (DMN)
Dorsolateral prefrontal cortex (DLPFC) tends to be hypoactive or hyperactive in depression?
hypoactive
Name a task that can assess executive-control/ working memory
Digit sorting task
Depression is associated with increased or decreased amygdala activity in response to emotional information processing?
Increased
Depression is associated with increased or decreased Dorsal Lateral prefrontal cortex (DLPFC) activity in response to cognitive tasks?
Decreased
Depressed individuals display decreased or increased relationships between amygdala and DLPFC activity?
Decreased
Hyperactive sgACC is associated with which mental disorder and anticorrelated with activity in which brain region?
Hyperactive sgACC is associated with MDD and anticorrelated with activity in dlPFC
Give a brief definition of psychotherapy
Identify, evaluate, challenge and modify dysfunctional beliefs and alter maladaptive behaviors
Give some examples of symptom-based subtypes of MDD
Melancholia, psychotic depression, atypical depression, anxious depression
Give some examples of aetiologically-based subtypes of MDD
Adjustment disorders, early trauma depression, reproductive depression, perinatal depression, organic depression and drug-induced depression
Give some examples of time of onset-based subtypes of MDD
early and late onset depression, seasonal affective disorder
