4. Mood Disorders Flashcards
Etiology of Depression
- Genetics
- 40-70% chance of developing depressive episode if 1st degree relative suffer from depressive episode - Organic
- Cushing syndrome, Addison disease, Parkinson disease, stroke, epilepsy, coronary artery disease, thyroid
- Medications - Psychosocial Factors
- Adversity in childhood
— Maternal loss, disruption of bonding
— Poor parental care
— Physical / sexual abuse
- Adversity in adulthood
— Women: absence of a confiding relationship
— Men: unemployment, divorce
- Recent life events
— Loss of a child
— Death of a spouse
— Divorce
— Marital separation
— Imprisonment
— Recent death of a close family member
— Unemployment - Presence of cognitive errors
- Magnification: tendency to magnify the magnitude of a failure and dismiss all previous successes
- Overgeneralisation: generalisation of failure in one area of life to other areas of life
- Personalisation: feeling that one is entirely responsible for failure and discounting the role of other individuals in responsibility for failure
- Selective abstraction: choose to focus on negative aspects, forget positive aspects
DSM-5 Diagnostic Criteria for Depressive Disorder
At least __ of the following symptoms for a minimum duration of __ weeks
At least 5 of the following symptoms for a minimum duration of 2 weeks:
MSIGECAPS
1. Low mood for most of the days (core feature)
2. Anhedonia: Diminished interest (no derived pleasure) in almost all activities (core feature)
3. Weight loss, loss of appetite
4. Sleep difficulties
5. Psychomotor changes (agitation or retardation)
6. Low energy
7. Feeling worthless, or excessive guilt
8. Attention and concentration difficulties
9. Recurrent passive or active ideations of self-harm and suicide
+ Symptoms must cause marked impairments in terms of premorbid functioning
More serious depressive subtypes
With psychotic features (mood congruent/incongruent)
With catatonia
Recurrent Depressive Disorder
At least 2 MDD episodes with intervals of at least 2 consecutive months (in which criteria are not met for a major depressive episode)
Cyclothymia
Numerous episodes with hypomanic symptoms and depressive symptoms over a duration of at least 2 years
*episodes do not meet the full diagnostic criteria for hypomania or depression
*must not be free from symptoms for more than 2 months in duration each time
Dysthymia (persistent depressive disorder)
Pervasive depressed mood for most part of the days for a total duration of at least 2 years
For dysthymia, apart from depressed mood, patient should have at least 2 of the following symptoms:
HE’S 2 SAD
Hopelessness
Energy loss or fatigue
Self-esteem is low
2 years minimum of depressed mood most of the day, for more days than not
Sleep is increased or decreased
Appetite is increased or decreased
Decision-making or concentration is impaired
Premenstrual Dysphoric Disorder
Onset of symptoms should be at least in the week prior to the onset of menstruation, and symptoms should improve a few days after the onset of menstruation
Intensity of symptoms should be minimal or resolved post-menstruation
Features of Atypical Depression
Reactive Mood
Appetite increase
Increase sleep
Leaden paralysis (heavy sensations in limbs)
Sensitivity to interpersonal rejection
Differential diagnosis for depressive disorder
Adjustment disorder
Bipolar disorder
Schizoaffective disorder
Schizophrenia with predominant negative symptoms
Dementia
Parkinson’s disease
Post-stroke depression
Organic causes
Substance misuse
Medication-induced
Questionnaires used in depression
- Beck Depression Inventory
- Hamilton Depression Scale
- Montgomery-Asberg Depression Rating Scale
“Psychosocial” management of patients with depression
Cognitive Behavioural Therapy
Interpersonal Therapy
Psychoeducation
Supportive therapy
Counselling
Sleep hygiene advice
“Bio” management of depression
- Selective serotonin reuptake inhibitors (1st line)
- Serotonin noradrenaline reuptake inhibitors (2nd line)
- Noradrenaline Specific Serotonin Antidepressant (NaSSAs)
- Noradrenaline Dopamine Reuptake Inhibitor (NDRI)
- Tricyclic Antidepressants (NEVER 1st line)
- Monoamine Oxidase Inhibitors (MAOi)
Indications of SSRIs
- Depressive disorder
- Anxiety disorder
- Obsessive compulsive disorder
- Bulimia nervosa (fluoxetine)
Absolute contraindication to SSRIs
Mania
MOA of SSRIs
- Selectively block reuptake of serotonin at presynaptic nerve terminals
- Increase serotonin concentration at synapses
Examples of SSRIs
Fluoxetine, fluvoxamine, sertraline, paroxetine, escitalopram
General S/E of SSRIs
- GI (most common): nausea, abdo pain, diarrhoea, constipation
- Autonomic: agitation, tremor, insomnia
- Sexual dysfunction (loss of libido, delayed ejaculation)
- Discontinuation symptoms (flu-like sx upon stopping anti-Ds abruptly)
— depends on half life - [Black box warning] Increased suicidal ideation (in <24yo in first 1-2 weeks of initiation)
- Serotonin syndrome
- Maniac episode if underlying bipolar
- Cardio-toxicity in overdose (very low risk)
- Hyponatremia 2’ SIADH
Discontinuation symptoms
FINISH
- Flu-like symptoms
- Insomnia
- Nausea
- Imbalance
- Sensory disturbances
- Hyperarousal
How does discontinuation symptoms occur?
Increased serotonin due to SSRIs -> upregulation of receptors
When SSRI is withdrawn
-> receptors don’t down-regulate immediately
How long does it take for the anti-Ds to take effect?
2-4 weeks for initial effects
4-6 weeks for good effects
Pros of Fluoxetine
Longest half life
-> lowers risk of discontinuation sx
-> therapeutic effects last longer than 5 days as fluoxetine breaks down into active metabolite which lasts ~1 week
=> requires 5 weeks washout if starting MAOi
Safe in overdose
Duration of washout for fluoxetine if starting MAOi
5 weeks
Cons of Fluoxetine
- Significant P450 interactions -> reduce use in patient with multiple medical co-morbids
- Initial activation -> increase anxiety and insomnia
- Do not give patients with bipolar depression due to long half life -> can lead to mania
Pros of Fluvoxamine
- Possess analgesic properties
- Sedating (give @ night)
- Less initial activation compared to other SSRIs
Cons of Fluvoxamine
- Short half life -> higher risk of discontinuation sx
- Causes weakness
- Significant P450 interactions -> reduce use in patient with multiple medical co-morbids
Pros of Sertraline
- Good in prolonged QTc -> safe for cardiac patient
- Less sedating than paroxetine
- Very weak P450 interactions
- Sleep wake neutral
- Safe for those with recent AMI
- Safest antiD in pregnancy
Cons of Sertraline
- Full absorption requires a full stomach
- Increased number of GI effects especially diarrhoea -> colitis
Pros of Paroxetine
Short half life with no active metabolite -> no build up
Cons of Paroxetine
- Short half life -> discontinuation sx
- Significant CYP206 inhibition
- Sedating
- Weight gain
- Anticholinergic sx
- Avoid in pregnancy (teratogenic)
Pros of Escitalopram
Lesser drug-drug interaction
Sleep wake neutral
Cons of Escitalopram
Not safe to combine with other drugs, causing QTc prolongation
Nausea, headache
Expensive
Examples of Serotonin Noradrenaline Reuptake Inhibitors
Venlafaxine
Duloxetine
MOA of SNRIs
Blocks serotonin and noradrenaline reuptake
Indications for SNRIs
MDD
Anxiety disorders
Good for low energy symptoms
Neuropathic pain (has analgesic properties)
C/I for SNRIs
Hypertension
S/E of SNRIs
Hypertension
Sexual dysfunction
Headache, nausea
Palpitations
Pros of Venlafaxine
Minimal DDI, no P450 activity
Short half life and fast renal clearance
Cons of Venlafaxine
Increase 10-15mmHg diastolic bp
Sexual S/E
QTc prolongation
Examples of Noradrenaline Specific Serotonin Antidepressant (NaSSAs)
Mirtazepine
MOA of NaSSA
5HT2 and 5HT3 antagonist
*effect on 5HT3 receptor is less likely to cause nausea side effect
Indications of NaSSA
MDD
Good for insomnia sx -> very sedating at lower doses
Good for low appetite (increases appetite and weight gain)
S/E of NaSSA
Weight gain (increase serum cholesterol and triglycerides) due to increased appetite
Sedation
Agranulocytosis
Example of Noradrenaline Dopamine Reuptake Inhibitor (NDRI)
Bupropion
Pros of NDRI
Good as augmenting agent
Weight loss effect
Nil sexual dysfunction
Nil sedation
Nil cardiac s/e
Second line ADHD agent
S/E of NDRI
Insomnia
AVOID if risk of seizure (lowers seizure threshold)
Abuse potential
Agitation, anxiety
Examples of Tricyclic Antidepressants
Amitriptyline
Nortriptyline
Desipramine
Imipramine
MOA of TCAs
Inhibit uptake of serotonin (mainly) and noradrenaline
S/E of TCAs
- Lethal in overdose (avoid in suicidal patients)
- Cardiotoxic -> QT prolongation even at therapeutic serum level
- Lower seizure threshold
- Hyponatremia
- Anticholinergic (dry eyes, dry mouth, constipation, urinary retention, blurred vision)
- Anti-histaminic (sedation and weight gain)
- Anti-adrenergic (orthostatic hypotension, sedation, sexual dysfunction)
Examples of Monoamine Oxidase Inhibitors (MAOi)
Moclobemide
MOA of MAOi
Binds irreversibly (but moclobemide binds irreversibly) to monoamine oxidase -> increases noradrenaline, serotonin, dopamine
S/E of MAOi
Serotonin syndrome (if combined with other antiDs)
Tyramine HTN crisis
- > avoid wines, cheese, fermented beancurd, cheese, cured meats, sympathomimetics
(Tyramine will increase release of noradrenaline hence if patient is on MAOi and eats tyramine, it will increase noradrenaline)
What is the washout period before starting MAOi for other drugs?
2 weeks washout period except fluoxetine - 5 weeks
Treatment mx for 1st episode of depression
Continue tx for 6-9 months after resolution of sx
If stopped immediately upon recovery, 50% can have relapse
Treatment mx for repeated episodes of depression
Continue tx for longer eg 2 years after resolution of sx
What is tx resistant depression?
MDD that fails to respond to 2 different antiDs (given as monotherapy at optimum doses)
Mx for tx resistant depression
- Change antiD
- Combine antiD (beware serotonin syndrome esp MAOi)
- Augmentation (combine antiD with mood stabilisers/anti-psychotics or neurostimulation)
- ECT (actively suicidal, refusing food, catatonic, refractory to meds)