Mood disorders Flashcards Preview

6P > Mood disorders > Flashcards

Flashcards in Mood disorders Deck (36):
1

Unipolar depression epidemiology

Avg age of onset 29
ave # of lifetime episodes: 4
Prevalence: 12 month - 7%
lifetime - 17%
all depression life-time prevalence: 21

2

Unipolar depression risk factors

female sex - 1.5-3x starting in early adolescence
divorce
age
non-black&nonhispanic,
non-white
non-studying adolescent

3

Major depression diagnosis

MDD = major depressive disorder; (MDE: episode)
Neurovegetative/vegetative symptoms
DSIGECAPS:
>=5 of the following for >= 2 weeks, one of criteria must be either depressed mood or anhedonia:
Depressed mood
Sleep disturbance
loss of Interest in pleasurable activities
Guilt
low Energy
Concentration difficulties
Appetite disturbance
Psychomotor retardation
Suicidal ideation

4

Major depressive disorder comorbidities

borderline personality disorder
anxiety disorders
OCD
eating disorders
substance misuse

5

BAD-I diagnosis

>=1 manic episode +/- MDEs
Expansive/irritable mood nad persistently increased goal-directed activity or energy plus >=3 (or >=4 if mood is only irritable) of the following, lasting >=1 week:
DIGFAST
Distractiliby
Increase in goal-directed activity
Grandiosity
Flight of ideas
Activities with high potential for painful consequences
Sleep decreased
Talkative/pressure of speech

Marked FUNCTIONAL IMPAIRMENT

6

BAD-II diagnosis

Abnormally/persistently elevated, expansive, or irritable mood plus abnormally & persistently increased activity/energy lasting >-4 days, during which >=3 of following occur:
DIGFAST

Unequivocal change in functioning observable by OTHERS
Episode is not severe enough to cause marked impairment in function/require hospitalization

7

Bipolar affective disorder comorbidities

ADHD
substance misuse
anxiety disorders

8

Bipolar I overview

>=1 manic episode +/- depressive episodes

9

Bipolar II overview

>=1 hypomanic episode +/- >=1 depressive episodes
never had full mania

10

Cyclothymic disorder diagnosis

>=2 y (1 in children/adolescents), numerous periods with hypomanic symptoms that do not meet criteria for hypomanic episode + numerous periods with depressive diagnoses that do not meet criteria for MDE
No symptom-free period >=2 mo at a time
during 2 y period, hypomanic/depressive symptoms have been present for at least half of the time
Have never met criteria for MDE, manic episode or hypomanic episode
Symptoms cause clinically significant distress or impairment

11

GMC rule out

general medical condition!
TSH, Na, B12, UTI
Liver disease, renal disease, cardiac disease, dementia, neurological disease

12

Dysthymia diagnosis

persistent depressive disorder
Depressed mood for most of day, for more days than not, for >=2 years (1 in children/adolescents)
While depressed, >=2 of :
- vegetative symptoms: appetite/sleep/energy changes
- psychological symptoms: low self-esteem, poor concentration/indecisiveness, feeling of hoplelessness

No symptom free period >=2 months at a time
clinically significant distress or impairment

13

Biogenic amine hypothesis

changes in neurotransmitter levels and regulation
deficiencies in dopamine, serotonin, norepinephrine
leading to receptor upregulation

14

Neurobiology of mood disorders

Biogenic amine hypothesis
post-synaptic receptor changes
neuropeptide, neuroendocrine and hormonal changes (cortisol, TSH)
regional brain dysfunction (blood flow, regional metabolism alterations)
Signal transduction abnormalities

15

Norepinephrine role in mood

energy
interest
motivation
anxiety, irritability

16

Serotonin role in mood

impulsivity
sex
appetite
aggression
anxiety
irritability

17

Dopamine role in mood

motivation
drive
sex
appetite
aggression

18

Signal transduction abnormalities in depression

Brain Derived Neuropathic factor (BDNF)
sustains viability of neurons
Repressed under stress, potentially leading to atrophy of hippocampus
5HT/NE can help regulate BDNF
Imaging studies confirm reduced volume of hippocampus in depression and anxiety

19

Pathophysiology of bipolar disorders

not well understood!
NT theories
Changes in GABA, ACh
Sensitization/kindling theories
Hormones (cortisol, thyroid)
changes in electrolyte balance
alterations in membrane/secondary messenger systems
Circadian rhythm theories
genetics

20

Risk factors for bipolar disorder

Family history - 75% concordance in twins
Seasonal changes
Environmental stressors
Hx of antidepressant use/electroconvulsive therapy

21

Catecholamine theory

depression related to decreased catecholaminergic NT caused by NE deficiency
Depletion studies showed relapse in previously controlled depression
Animal models of altered catecholamine metabolism show abnormal exploratory behaviour, conditioned avoidance and reward-seeking behaviour

22

Serotonin production metabolism

Tryptophan --> 5-hydroxy tryptophan --> serotonin

23

Serotonin in depression

low levels of 5HT metabolite 5HIAA reported in CSF in depressed patients
Relapse in patients previously well-controlled with SSRIs

24

Consequences of interference with serotonin metabolism

irritability
insomnia
hyperactivity
hypersexual behaviours

25

Monoamine hypothesis of depression

Depression caused by decreased levels of centrally available monoamines (NE, 5HT)
Cause unknown
Evidence: antidepressants increase monoamine levels
Reserpine: depletion of monoamines by irreversibly blocking vesicular monoamine transporter may precipitate depression in some patients
Biochemical effect of antidepressants immediate, but clinical effect takes a while (antidepressants lead to compensatory adaptive changes in receptors - desensitization)
5HT/NE/DA depletion does not induce depression in healthy subjects
Antidepressants are not effective in all patients

26

Newer theories of depression

Anti-depressants produce secondary transcriptional and translational changes --> mediate molecular/cellular plasticity --> normalize limbic/cortical circuits

27

Neuroanatomy in depression

Dysfunctional connectivity between regions of frontal cortical and limbic system
Decreased size of frontal/cingulate cortices, amygdala
Activity of amygdala increased
Hippocampal volume reduced (associated with greater lifetime depression, stressful life events)
Hippocampus is the major site of neurogenesis in adult brain

28

Prefrontal cortex symptoms in depression

guilt, suicidality, worthlessness
mood
psychomotor fatigue (mental)
concentration, interest, pleasure

29

Amygdala symptoms in depression

guilt
suicidality
worthlessness
mood

30

HPA axis in mood disorders

Dysfunction of HPA axis established in depression --> excess secretion of cortisol
Dexamethasone non-suppression more common in depression (impaired feedback regulation)
Changes in HPA axis only present in ~50% of patients
Chronic secretion of cortisol can alter cognitive function, decrease hippocampal volume
Brain changes likely take place after first episode
Amygdala stimulates hypothalamus to produce CRF, Hippocampal inhibits hypothalamus

31

Cortisol --> hippocampal volume

Direct toxic effects / neurotrophic factors
Chronic stress suppresses BDNF

32

Genetics of depression

twin concordance 35-50% for major depression (lower than bipolar)
No specific genes
Carriers of short form of serotonin transporter --> higher risk for depression if they also experience stressful life experiences
- associated with increased activation of amygdala in response to fearful faces

33

Depression and immune system

Viral/bacterial infection --> sickness behaviour
Overlap significantly with symptoms of depression
Inflammatory disease/taking interferons --> increased risk of psychiatric disorders

34

Pathophysiology of bipolar disorder

Less known
Manic: increased catecholamines
Likely due to dysfunction of same circuits as depression (GABA/glutamate, HPA axis)
Abnormalities in cellular signal transduction cascades, second messenger systems, oxidative stress, dysregulation of energy metabolism, myelination
Highly heritable, genetic overlap with schizophrenia

35

SAD PERSONS scale

for suicide risk
Sex (male)
Age (15-24, >65)
Depression
Prior history
Ethanol abuse
Rational thinking loss (psychosis)
Support system loss
Organized plan
No SO
Sickness

36

IS PATH WARM

dynamic factors of suicide risk to determine need for further assessment
Ideation
Substance abuse
Purposelessness
Anxiety
Trapped
HOpelessness
Withdrawal
Anger
Recklessness
Mood change