Lecture 22: Introduction to Psychiatry, Depression, and Anxiety Flashcards
What is a psychiatrist?
a physician who specializes in the diagnosis and treatment of mental disorders
MD (4 years)
residency (5 years)
How do psychiatrists treat people?
psychotherapy
psychopharmacology
somatic therapies
lifestyle modification
What are some conditions that are classified as mental disorders?
depressive disorders
bipolar disorders
schizophrenia
anxiety disorders
post-traumatic stress disorders
obsessive-compulsive disorder
personality disorders
substance use disorders
neurocognitive disorders
What is the DSM-5 definition of a mental disorder?
a mental disorder is a syndrome characterized by clinically significant disturbance by clinically significant disturbance in an individual’s cognition, emotion regulation, or behavior that reflects a dysfunction in the psychological, biological, or developmental processes underlying mental functioning
mental disorders are usually associated with significant distress or disability in social, occupational, or other important activities
What is not a mental disorder according the the DSM-5?
an expected or culturally approved response to a common stressor or loss is not a mental disorder
socially deviant behavior and conflicts that are primarily between the individual and society are not mental disorders unless the deviance results from a dysfunction in the individual
What conditions need to met in order to diagnose a mental disorder?
cause clinically significant distress and/or cause difficulties in function or disability
What are psychotherapies?
involve addressing an individual’s thoughts, behaviors, emotions, and relationships through developing insight, changing conditions and changing behaviors
What are pharmacotherapies?
drugs are often symptom specific, not diagnosis specific
What are somatic therapies?
involve stimulating neural circuits
electroconvulsive therapy
transcranial magnetic stimulation
deep brain stimulation
vagal nerve stimulation
phototherapy
What is DSM-5 criteria major depressive episode (MDE)?
at least five of below must be present in 2-week period, and either 1 or 2 must be included
1. depressed mood
2. diminished interest and pleasure (anhedonia)
3. unintentional weight change (>5% in month) or change in appetite
4. sleep disturbance
5. psychomotor agitation or retardation
6. fatigue, lethargy, lack of energy
7. feelings of guilt or wothlessness
8. trouble concentrating or thinking
9. recurrent thoughts of death or suicidal ideation
What conditions must symptoms meet in order to be diagnosed with a major depressive episode?
be disruptive enough to impair normal function
not occur exclusively in the context of schizophrenia/other psychotic disorder
not be due to the effects of a substance
occur most days over the 2 weeks
What is the course of major depressive disorder (MDD)?
average age of onset = 25-30
onset may be sudden or gradual: stress can be a precursor and act as a predisposition
MDD is a recurrent illness: after one MDE, the likelihood of a second episode is about 50%, after two MDE, the likelihood of a third is about 80%
Is MDD due to nature or nurture?
MDD is 2-3x more prevalent if there is a first-degree biological relative who suffers from it
twin and adoption studies, 20-30% of identical twins are not concordant for MDD
there must be an environmental element in addition to genetic vulnerability
What are adverse childhood experiences (ACES)?
negative events that occur in childhood that are associated with increased rates of heath conditions
focus is on negative events and does not take into account protective factors
ACES include abuse, neglect, and household, familial, and environmental exposures
protective factors may mitigate some of the risk and impact associated with ACES
What is the top protective factor for ACES?
have at least one adult in your life that you trust
What are higher rates of ACES associated with?
higher rates of ACES associated with lower educational and occupational achievement, higher rates of mental health disorders, substance use, suicide, cancer, diabetes
What are the anatomical aspects of major depression?
brain regions most implicated: medial prefrontal cortex, hypothalamus and hypothalamic-pituitary-adrenal axis, and hippocampus
reduced volumes in the brains of individuals with depression likely reflects impaired neurogenesis (high levels of stress hormones)
What is the impact of MDD?
lifetime prevalence for MDD in adults: 17%
10-20% for women and 5-10% for men
estimated to cost the Canadian economy $14.4 billion annually (presenteeism: underperforming at work)
with increasing severity and chronicity of the initial episode, due in some case to a delay in receiving effective treatment, the less likely is a full recovery
What is MDD remission?
your depression score is 20 to begin with, when it drops to half you are in remission
What is MDD recovery?
back to non-impactful
What is the biogenic amine (monoamine) hypothesis of depression?
depression is the result of a functional deficiency of noradrenaline (NA) and/or 5-hydroxytryptamine (5-HT, serotonin) at specific synapses in the central nervous system
What neurotransmitters and pathways are involved in the biology of depression?
neurogenesis
dopamine
acetylcholine
GABA, glutamate
systemic glucocorticoids
inflammation
endocannabinoids
neuroactive steroids
What are characteristics of antidepressants?
double-blind placebo-controlled studies show that all antidepressants are more or less equally effective in treatment, with:
response rates of 60-80%, remission 30-40%
placebo response 30-40%, remission 10-20%
major differences of antidepressant are due to side effects and metabolism
How long does antidepressant treatment last?
initial treatment for at least one year after remission to reduce rates of relapse
higher rates of relapse if medication stopped early
some individuals end up on longer or continuous treatment if they have repeated or severe episodes
increased suicidality after the initiation of an antidepressant may be because the patient has increased energy, but mood remains low
What are MAO inhibitors?
inhibit monoamine oxidase (MAO), allowing the amine neurotransmitters to accumulate within the nerve terminal
it is supposed that this excess neurotransmitter then flows into the synaptic cleft and onto the postsynaptic receptors
i.e. phenelzine, tranylcypramine
What are tricyclic antidepressants?
inhibit the active reuptake of NA and 5-HT back into nerve terminals, resulting in an increased functional availability of these neurotransmitter amines at central receptors
lots of side effects, arrythmia, lethal overdose
i.e. amitriptyline, nortriptyline
What are selective serotonin reuptake inhibitors (SSRIs)?
strong inhibitors of 5_HT reuptake, but unlike the TCAs, they and their metabolites have little effect on NA reuptake into nerve terminals
much safer in overdose
i.e. fluoxetine, paroxetine, citalopram
What are serotonin-norepinephrine reuptake inhibitors?
inhibit the reuptake of 5-HT and NA from the synaptic cleft
i.e. venlafaxine, duloxetine
What is electroconvulsive therapy (ECT)?
an effective treatment for severe depression
muscle relaxant
unknown mode of action (increases neurogenesis)
used for treatment resistant depression, depression with psychotic features
side effect: mold memory loss around time of procedure
ECT can be given in conjunction with antidepressants and antipsychotics
ECT usually raises mood for 4-6 months and medication is often needed for maintenance
some individuals receive ongoing maintenance ECT to prevent relapse
What are other uses of antidepressants?
useful for the treatment of a number of other disorders, including anxiety disorders, eating disorders, some personality disorders, and chronic pain syndromes
What is anxiety?
anxiety itself is a normal adaptive response to perceived threats or danger
anxiety becomes a disorder when it results in significant impairment in function and causes significant personal distress
the 12 month prevalence rate for having an anxiety disorder is around 18%
What is panic disorder?
unpredictable and recurrent attacks of panic characterized by upsetting physical symptoms such as tachycardia, chest pain, sweating, tremor, nausea, and overwhelming sensations of fear or loss of control
recurrent panic attacks without clear cause
might have anxiety before that causes panic attacks
What is social anxiety disorder?
extreme and persistent anxiety about social situations, leading to avoidance of those situations, or pronounced anxiety attacks on exposure or even on anticipation of exposure to the situation
What are specific phobias?
clinically significant anxiety provoked by exposure to a specific feared object or situation, often leading to avoidance behavior
identifiable causes
What is generalized anxiety disorder?
excessive anxiety and worry, occurring most days for more than six months, with symptoms of motor tension, autonomic hyperactivity, apprehensive expectation, vigilance and scanning
What are the neurochemical bases of anxiety disorders?
thought to be due to overactivity of neural circuits involves in fight/flight/freeze
mostly involve serotonergic and noradrenergic synapses
What are the anatomical aspects of anxiety?
limbic system is involved
thalamus, amygdala, hippocampus, locus ceruleus
How is the thalamus involved in anxiety?
the thalamus is a hub for interpreting sight and sounds
it takes input and then send signals to the appropriate part of the cortex
How is the amygdala involved in anxiety?
the amygdala is the trigger for the fear response
it sends signals to the locus ceruleus as well as the hypothalamus and pituitary which activate hormonal responses
How is the hippocampus involved in anxiety?
the hippocampus stores raw information from the senses along with the emotional tone and links memories to emotional states
How is the locus ceruleus involved in anxiety?
the locus ceruleus receives signals from the amygdala and sends signals via noradrenaline to the rest of the body to trigger a classic fear response or flight or fight response
What treatments of anxiety disorders?
combinations of cognitive behavioral therapy (CBT) and medications are often used to treat anxiety disorders
can’t change anxiety so change thoughts
What are medications used to treat anxiety disorders?
antidepressants (5-HT, NA)
benzodiazepines (GABA)
beta-blockers (NA): slow heartrate, drop blood pressure, so they are likely to faint
What is the mechanism of action of the benzodiazepines?
the benzodiazepines interact with binding sites on the GABA-A receptor and potentiate GABA-mediated increases in chloride permeability
What are the characteristics of dependence on benzodiazepines?
psychological dependence does develop to the benzodiazepines in some patients (estimates range up to 25%)
withdrawal effects can occur on cessation of treatment, and these include anxiety and insomnia, but can be as severe as seizures and hallucinations
concerns about these phenomena have been responsible for a significant decline in the use of these agents in recent years, but they are still useful drugs
What is psychological dependence?
this medication makes me feel better so I need to take it or something bad will happen
What is PMD?
depression leading up to a period
What is SAD?
seasonal affective depression
worse as light levels fall
What is PPD?
post-partum depression
