Depressive disorder Flashcards
Define depression.
Depressive disorders are typically characterised by
- persistent low mood,
- loss of interest and enjoyment,
- neurovegetative disturbance,
- and reduced energy,
causing varying levels of social and occupational dysfunction.
How common is depression?
- WHO estimates that 300million affected worldwide
- 3rd most common reason for GP consultation in UK
- Anually 5% of adults have a depressive episode
- Chronic illness is linked to depression
Describe the aetiology of depression.
Probably some gene-environmental susceptibility
Pathophysiology
Abnormal concentrations of neurotransmitter - monoaminergic theories of depression; dopamine may be related to impaired motivation and concentration; low noradrenaline and dopamine may cause fatigue and hypersomnia; impaired noradrenaline and serotonergic regulation may contribute to physical symptoms.
Dysregulation of HPA axis - depressed individuals, when given a bedtime bolus dose of glucocorticoid dexamethasone, fail to inhibit normal, circadian surge in cortisol the next morning (dexamethasone supression test)
Abnormalities of second messenger systems
What are the risk factors for depression?
- Personal or family history of depression
- Age >65
- Postnatal status
- Personal or family history of depressive disorder or suicide
- Corticosteroid
- Interferon
- Propanolol
- Oral contraceptives
- Co-existing medical conditions
Uncommon:
- Isotertinoin
- Comorbid substance use
- Personality disorder
- Gene-environment interaction
What are the symptoms of depression?
- Depressed mood
- Anhedonia
- Functional impairment e.g. social/occupational
- Weight change
- Libido changes
- Sleep disturbance
- Psychomotor problems
- Low energy
- Excessive guilt
- Poor concentration
- Suicidal ideation
- *
Define anhedonia.
According to DSM-5, major criterion for diagnosis: diminished interest or pleasure in all or almost all activities most of the day, nearly every day, for a period of 2 weeks along with 4 other symptoms of depression
People will also have a CONSTANT low mood - almost feeling numb.
What must you exclude when diagnosing depression?
- Bipolar disorder
- Substance abuse/medication side effects
- Medical illness (somatic)
- Schizophrenia (psychotic)
SO the symptoms should not be due to a physical/organic factor or illness (like substance abuse and medical illness respectively, although the latter can co-exist)
What is the criteria for diagnosing major depression?
Criteria for major depression: according to DSM-5, is five or more depressive symptoms, including depressed mood or anhedonia, for at least 2 weeks.
What are psychotic symptoms?
Processing reality less well
Hearing voices etc.
What is the classification of depression?
The DSM-5 divides depression into:
- Major depressive disorder
- Persistent depressive disorder (dysthymia)
- Premenstrual dysphoric disorder
- Other depressive disorders (due to substance abuse, medication side effects, medical conditions, or other specified or unspecified causes).
Distinguished based on length and number of symptoms in addition to sad mood and/or anhedonia. Degree of functional impairment and severity of symptoms also considered.
What are the levels of severity of depression?
Subthreshold - <5 symptoms.
Mild depression - few, if any, symptoms ove the 5 required for diagnosis, –> only minor functional impairment.
Moderate depression - symptoms or functional impairment are between ‘mild’ and ‘severe’.
Severe depression - most symptoms present and the symptoms markedly interfere with normal function. It can occur with or without psychotic symptoms.
What is the most important cause of missed diagnosis of depression?
Somatisation - pt can present with somatic symptoms or a pre-existing illness which can divert attention away from mental state. Can also present as pseudodementia with memory and behavioural problems.
- Sensitivity 50%*
- Specificity 81%*
- Risk of misidentification outweighs risk of missed cases*
What questions does NICE recommend asking at-risk groups? What assessments exist?
During the past month have you:
- felt low, depressed or hopeless?
- had little interest or pleasure in doing things?
Self report symptom scales include:
- PHQ-09
- HAD scale
- Beck’s depression inventory II
Outline a full clinical assessment of depression in a consultation.
- Full hx and exam, including MSE. Inquire into suicidal ideas, delusions, hallucinations. Consider organis causes and establish length of episode.
- Social - review functional/interpersonal difficulties. Involve family members. Note for evidence of sel-neglect, psychosis sor agitation.
- PMH - Past psychiatric history, previous episodes, previous treatment and other PMH.
- Patient safety and risk to others - suicidal intent should be assessed regularly. Directly ask about this
https://patient.info/doctor/suicide-risk-assessment-and-threats-of-suicide
What investigations should you do for depression?
Exclude an organic cause for depression.Not mandatory and done according to clinicl judgement.
Bloods - glucose, U&E, LFTs, TFTs, calcium levels, FBC, inflammatory markers
Other - magnesium levels, HIV, syphilis, drug screen
Imaging - MRI/CT if presentation is atypical or suspicion of intracranial lesion e.g. in headache
