Overview

Making Diagnosis

Clinical Features

• For Diagnosis → symptoms must be present for ≥2 weeks and must cause clinically significant distress and/or impairment.
• Core Symptoms → low mood, low energy (anergia), loss of interest in previously pleasurable activities (anhedonia).
  • Biological Symptoms → changes in appetite, changes in sleep, changes in memory/concentration.
• Classifying Severity
  • Mild → 2 core symptoms + 2 other symptoms.
  • Moderate → 2 core symptoms + 3 other symptoms.
  • Severe → 3 core symptoms + 4 other symptoms.
  • Severe Depression with Psychosis → above + psychotic symptoms (delusions +/- hallucinations).

Investigations

• PHQ-9 → used in primary care to monitor the severity of depression and the response to treatment.
• Rule out Organic Causes → Full Blood Count (FBC), Thyroid Function Test (TFT), Urea and Electrolytes (U&E), Liver Function Test (LFT), Glucose, B12/folate levels, cortisol levels, toxicology screen, and imaging of the Central Nervous System (CNS).
• Always check for concurrent mood elevation → BPAD.

Management Plan

• ‘Less Severe’ Depression (PHQ-9 <16) → guided self-help > group CBT > individual CBT (in order of NICE preference).
  • Step 1: watchful waiting for 2 weeks (dependent on patient preference and clinical judgement). Educate on sleep hygeine, exercise, self-help and information/support.
  • Mild (if still sx after 2 weeks watchful waiting - persistent subthreshold depression sx) → low-intensity pscyhosocial interventions (group CBT, computerised CBT, guided self-help).
• ‘More Severe’ Depression (PHQ-9 ≥16) → combination of CBT + SSRI.
  • Moderate → high-intensity psychosocial interventions (individual CBT, interpersonal therapy [IPT>CBT if due to death]) and medications.
    • Medications
      1. First Line → SSRI.
         • Sertraline → stepped increase from 50mg to 200mg (50mg increase every 2 weeks) over 6 weeks.
         • 2 trials of SSRIs before moving onto second line.
      2. Second Line → taper down SSRI, switch to SNRI.
         • Venlafaxine → stepped increase from 37.5mg BD → 75mg BD → 75mg morning / 150mg evening.
• SSRI’s → follow-up 2 weeks after starting (1 week if <25yo or increased suicide risk). Continue for at least 6 months after remission of symptoms to decrease risk of relapse. When stopping, reduce dose over a 4 week period.
  • Post-MI → sertraline. Children and adolescents → fluoxetine.
  • Adverse Effects → GI symptoms (most common), increased risk of GI bleeding (take PPI if prescribed an NSAID), hyponatraemia, restlessness, insomnia, increased fracture risk, sexual dysfunction.
  • Discontinuation Symptoms → flu-like symptoms, GI symptoms (pain, cramping, diarrhoea, vomiting), sweating, restlessness, paraesthesia, ataxia.
    • Paroxetine has highest incidence of discontinuation syndrome.
  • Interactions/Contraindications → NSAIDs (co-prescribe PPI), warfarin/heparin, aspirin, triptans (serotonin syndrome), MAOIs (serotonin syndrome).
    • Serotonin Syndrome → abrupt onset of fever, hypertension, tachycardia, confusion, agitation, hyperreflexia. Supportive treatment (active cooling), alongisde benzodiazepines which can help reduce agitation and muscle hyperactivity.
  • Switching SSRIs
    • Fluoxetine to another SSRI → fluoxetine has a long half-life. Must withdraw fluoxetine completely (wean - reduce dose over 2 weeks) with a wash-out period of 4-7 days until new SSRI is started.
    • When switching between other SSRIs (non-fluoxetine), the SSRI should be withdrawn completely (wean) before the alternative is started (immediately at low-dose).
    • Cross-taper if switching from SSRI (non-fluoxetine) to a TCA or SNRI.
  • Pregnancy
    • Weigh up risks and benefits when deciding to use SSRIs during pregnancy. 1st trimester: increased risk of congenital heart defects (particulary paroxetine). 3rd trimester: increased risk of persistant pulmonary hypertension of the newborn.
    • Breastfeeding → give sertraline or paroxetine.
• ECT → indications include severe depression (that is life-threatening), catatonia, or prolonged/severe manic episode.
  • Involves attaching electrodes to the scalp and passing an electrical current through them to induce a seizure. This is performed under general anaesthesia. It is thought to cause a neurotransmitter release, which improves symptoms. Full course comprises 12 sessions.
  • Reduce antidepressant medication prior to ECT.
  • Side-effects → memory impairment (retrograde [memories before ECT] > anterograde [problems forming new memories]), headache, confusion, cardiac arrhythmia and muscle aches.
  • Absolute Contraindications → raised ICP.