Major Depressive Disorder

DSM V categorise these as seperate disorders

• Depressive disorders
• Bipolar disorders
• Anxiety disorders

Depressive Disorders

• Major depressive disorder
• Other depressive disorder
  • Persistent Depressive Disorder
  • Substance/medication induced depression disorder
  • Depressive disorder due to another medical condition

Overview

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. Depression is the leading cause of disability and premature death in 18-44 yo and is predicated to be the 2^nd leading cause of disability in 2020.  20% of adults will have it at some point in their life, women are twice as likely. Depression will make up ~5-10% of people seen in primary care setting.

Grief	Depression
There is an identifiable loss	A specific loss may or may not be identified
The person’s focus is on the loss	The person’s focus is on self
Fluctuating ability to feel pleasure	Inability to feel pleasure
Fluctuating physical symptoms	Prolonged and marked functional impairment
Closeness of others is usually comforting	Persistent isolation from other and self
Able to feel a wide range of emotions	Fixed emotions and feeling “stuck”
May express guilt over some aspects over loss	Generalised feelings of guilt
Thoughts of death are typically related to wanting to be reunited with the deceased loved one	Thoughts of death related to feeling worthless, undeserving of life or unable to cope with the pain

Aetiology & Risk Factors

Aetiology

Multifactorial

Changes in brain

• No structural abnormalities
• Function abnormalities present:
  • Decreased activity in frontal lobe
  • Increased firing in the limbic system
  • Increase cortisol in blood
  • Altered neurotransmitter pathways
    • Serotonin
    • Dopamine
    • Noradrenaline

Risk Factors

Risk Factors

Age (onset peaks in late 20s)

Family history (3x risk with affected 1° relatives)

Personal history

Lower SES

Substance abuse

Adverse life events

Lack of confiding relationship

Physical illness

Clinical Manifestations

• Sleep changes
• Interest (decreased)
• Guilt (excessive)
• Energy (decreased)
• Concentration (decreased)
• Appetite changes
• Psychomotor agitation or retardation
• Suicidal ideation

Non-specific symptoms of Depression

• Abdominal pain
• Back pain
• Change in weight or appetite
• Constipation
• Fatigue
• Headache
• Insomnia or hypersomnia
• Joint pain
• Neck pain
• Weakness

Differential Diagnosis

• Bipolar Disorder
• Grief reaction
• Anxiety
• Hypothyroidism
• Multiple Sclerosis
• Dementia
• Other depressive disorder
  • Persistent Depressive Disorder
  • Substance/medication induced depression disorder (illicit drug withdrawal, antihypertensives, steroids)
  • Depressive disorder due to another medical condition

Investigations

• FBC (anaemia, infectious diseases)
• ESR
• EUC
• LFT
• Urinalysis – uraemia
• Thyroid function tests – hypothyroidism
• ECG – dysrhythmia -> cerebral infarct

Diagnosis

• 1 core symptom
• At least 4 associated symptoms (SIG-E-CAPS)
  • Sleep changes
  • Interest (decreased)
  • Guilt (excessive)
  • Energy (decreased)
  • Concentration (decreased)
  • Appetite changes
  • Psychomotor agitation or retardation
  • Suicidal ideation

Criteria for symptoms

• Pervasive (all day, most days)
• Persistent (2 weeks)
• Not better explained
• No manic or hypomanic episodes
• New signs and symptoms then normal that impact with daily function

Treatment

Psychological therapy

• Cognitive behavioural therapy
• Interpersonal therapy

Psychosocial treatments are first line treatments for mild depression. Usually psychotherapy is used in conjunction with pharmacotherapy.

Pharmacological therapy 

• SSRI (first line)
  • Certraline
• SNRI
  • Desvanlafaxine
• TCA
  • Amytriptaline
• Other
  • Mertazapine (safe in pregnancy)

None has been shown to be more effective then the other, so the choice depends on the adverse effects the patient can tolerate. SNRI are used first line because they generally have less side effects. When response to treatment is poor the diagnosis and compliance with treatment should be reassessed

Moderate/severe depression:

• Electro Convulsive Therapy
• Transcranial Magnetic Stimulation

Complications & Prognosis

Complications

• Sexual dysfunction and Gastrointestinal disturbance of SSRIs and SNRIs
• Risk of self-injurious behaviour
• Undesired weight gain from antidepressant

Prognosis

• Complete remission of symptoms and return to normal functioning are the therapy goals.
• For patients in their first episode of depression, treatment to remission may take up to several months and should be continued for a minimum of 9 to 12 months after remission.
• For patients who have had recurrent episodes, or in whom relapse or recurrence would likely convey a high risk, evidence supports prolonged antidepressant treatment.

Postpartum Depression

Many experience what is known as postpartum blues, in which there is sadness, strong feelings of dependency, frequent crying spells, and dysphoria. This occurs in up to one in seven women.

Postpartum blues usually last for several days to a week. In rare cases, postpartum depression exceeds in both severity and length that is observed in postpartum blues and is characterized by suicidality and severely depressed feelings.

Risk factors

• History of depression
• Family history
• Mental illness
• Recent stressful life events
• Poor social support
• Discontinuing pharmaceutical treatments
• Exposure to violence

Diagnosis

Management

For first-time mothers, adolescent mothers, and mothers who have experienced a traumatic delivery, home health visits, telephone-based peer support, and psychotherapy may help prevent peripartum depression.

• Mild to moderate depression – psychotherapy or selective serotonin reuptake inhibitors (SSRI’s)
• Moderate to severe depression – combination of psychotherapy and medication (SSRI’s are the safest)

Serotonin Syndrome

Serotonin syndrome is characterized by (in order of appearance) diarrhea, restlessness, extreme agitation, hyperreflexia, autonomic instability, myoclonus, seizures, hyperthermia, rigidity, delirium, coma, and death.