Affective Disorders Flashcards
How common is depression?
Prevalence 2-5%
1/5 will suffer at some point in their lives
Is depression more common in F or M?
2:1 F:M
What is the pathophysiology of depression?
Monoamine (MA) theory - depression associated with reduced noradrenaline or serotonin in brain
Antidepressants inhibit breakdown of MA rapidly but clinical improvements can take weeks
List the monoamine neurotransmitters
Imadazoleamines - histamines
Catecholamines - adrenaline, noradrenaline, dopamine
Indolamines - serotonin, melatonine
What are the core symptoms of depression?
1) Depressed mood for most of the day, every day
- Little variation in mood despite changes in time, circumstances or activity
- Possible diurnal variation (worse in morning and improving throughout day)
2) Anhedonia
3) Fatigue
What are the typical symptoms of depression?
Biological:
1) Poor appetite with marked unintentional weight loss
- >5% in past month
(Rarely inc appetite and weight gain)
2) Disrupted sleep
- Initial insomnia with early waking (3+ hrs)
3) Psychomotor retardation eg sluggish thought processes, limited spontaneous movement or restlessness
4) Decreased libido
5) Inability to concentrate
Plus:
6) Feelings of worthlessness or inappropriate guilt
7) Recurrent thoughts of death, suicidal ideation or suicide attempts
What is needed to diagnose depression?
At least 2 core symptoms + 2/more typical symptoms
Symptoms present every or nearly every day without significant changes throughout the day for over 2 weeks
Must represent a change from normal personality without alcohol/drugs, medical disorders or bereavement
List the ICD-10 categories for mild, moderate, severe depression
When should this be used?
Mild = 2 x core + 2 x typical Moderate = 2 x core + 3(+) typical Severe = 3 x core + 4(+) typical
First episode (further depressive episodes classified as recurrent depressive disorder)
List some ddx for depression
Psych - dysthymia, bipolar disorder, schizophrenia, anorexia nervosa, anxiety
Neuro - dementia, PD, HD, MS, stroke
Metabolic - hypoglycaemia, hypercalcaemia
Haem - anaemia
Inflammatory - SLE
Infections - syphilis, Lyme disease, HIV encephalopathy
Medications - anti-HTN, steroids, H2 blockers, sedatives, antipsychotics
Substance misuse - alcohol, BDZ, opiates
Sleep disorders
What psychotic symptoms may someone with depression suffer from?
Delusions eg poverty, guilt over things which could not be their fault, punishment, nihilism
Hallucinations eg auditory (accusatory, cries for help), olfactory (rotten food, faeces), visual (demons, corpses etc)
What investigations should be done for depression?
Bloods
- FBC: anaemia
- ESR
- B12/ filate
- TFTs
- Glucose
- Calcium
Urine toxicity Syphilis serology HIV Dexamethasone suppression test ACTH stimulation
What is the dexamethasone suppression test?
Dexamethasone reduces ACTH release in normal people
Thus taking dexamethasone should reduce ACTH and lead to decreased cortisol
Cortisol is measured either overnight (more common) or standard (3 days) after administration of dexamethasone
Why may pt with depression present with an abnormal dexamethasone suppression test?
NA inhibits corticotropin releasing factor, thus decreasing ACTH secretion by the pituitary, and in turn, cortisol secretion by the adrenal glands
Deficiency of brain NA can lead to both depressive symptoms and increased cortisol production
Episodes fo cortisol secretion are longer and more frequent in depressed patients, and the circadian rhythm of cortisol release is altered
Dexamethasone does not suppress plasma cortsol levels in pts cvs normal subjects
What is ACTH stimulation?
aka cosyntropin test / syncathen test
Measures the response of adrenal glands to ACTH (should release cortisol)
List some biological causes of depression (7)
1) Genetic serotonin transporter gene (FH++)
2) Abnormal concentrations of serotonin and other NTs
3) Disregulation of the HPA axis
- Inc cortisol in 50%
- Linked to adrenal hypertrophy and failed dexamethosone suppression test
4) Hypothyroidism
5) Postnatal
6) Chronic pain
7) Medications
List some psychological causes of depression (7)
1) Childhood trauma
2) PTSD
3) Low self esteem
4) Stress, lack of coping, lack of resilience
5) Attitudes and beliefs
6) Anxiety and guilt
7) Burden of chronic disease / comorbities
List some social causes of depression (8)
1) Isolation
2) Bereavement
3) Stress
4) Abuse
5) Relationships
6) SES
7) Homelessness
8) Education
List antidepressants which may be used in the management of depression
SSRIs = first line
SNRI - Serotonin noradrenaline re-uptake inhibitors
NARI - Noradrenaline re-uptake inhibitor
TCA - Tricyclics
MAOIs - Monoamine oxidase inhibitors
NASSA - Nonadreneric and specific serotonergic antidepressants
Give some examples of SSRIS
Fluoxetine Citalopram Escitalopram Sertraline Fluvoxamine Paroxetine
In which populations are SSRIs more commonly used?
Elderly
Anxiety
OCD
What are some side effects of SSRIs?
Nausea and vomiting common
Agitation
Sexual dysfunction - 70% affected and difficult to treat
Also dizziness, dry mouth, blurred vision
Which SSRIs prolong the QT interval?
Citalopram
Escitalopram
What is serotonin syndrome?
Acute toxic syndrome due to increased 5HT activity
How does serotonin syndrome present?
Confusion Myoclonic jerks and hyperreflexia Pyrexia and sweating GI symptoms Mood changes and mania Convulsions Death