FFinalistSouthampton · 2027
Psychiatry
AKT · Psychiatry/Mood

Depression

Overview

Persistent low mood and/or anhedonia ≥2 weeks with cognitive, somatic and functional change. NICE 2022 grades it less severe (PHQ-9 <16) vs more severe (≥16) rather than mild/moderate/severe.

Recognise

  • Core: low mood, anhedonia, low energy
  • Cognitive: guilt, worthlessness, poor concentration, hopelessness
  • Somatic: early-morning waking, diurnal variation (worse mornings), appetite/weight change, psychomotor change
  • Suicidal ideation — always ask

Red flags

  • Active suicidal intent/plan, psychotic features, severe self-neglect → urgent specialist/crisis referral

Differentials & how to tell them apart

Bipolar depressionask about past mania/hypomania — antidepressant monotherapy can trigger a switch
Hypothyroidismcheck TFTs; cold intolerance, bradycardia
Adjustment disorderclear stressor, milder, time-limited
Dementia (pseudodementia)depressed elderly may mimic cognitive decline — improves with mood treatment

Investigations

Clinical diagnosis. PHQ-9 to grade severity and track response. Screen: TFTs, FBC, glucose/HbA1c, U&E, calcium, B12/folate to exclude organic mimics. Risk assessment essential.

Management

  1. 1Less severe (PHQ-9 <16): do NOT routinely offer an antidepressant first-line. Offer guided self-help, CBT, behavioural activation, group exercise, or counselling by preference.
  2. 1More severe (≥16): offer a menu — individual CBT, an antidepressant (SSRI/SNRI), behavioural activation, or combined.
  3. 2If an antidepressant is chosen: SSRI first-line. Review within 2 weeks (1 week if <30 yrs — suicide-risk).Gate: Switch/augment only after ~4 weeks at therapeutic dose with no response
  4. 3Inadequate response: optimise dose, switch antidepressant (same or different class), add psychological therapy, then specialist augmentation.
Sertraline / citalopram (SSRI) — first-line drug if one is chosen
Mirtazapine — sedating, ↑appetite — useful with insomnia/poor appetite
Venlafaxine (SNRI) — second-line; ↑BP, discontinuation effects

Key points

<30 yrs: review within 1 week (SSRI suicidality signal). Pregnancy/breastfeeding: sertraline preferred. Continue antidepressant ≥6 months after remission to prevent relapse. Seasonal affective disorder (SAD) = recurrent depression with a seasonal (usually winter) pattern — treat as depression. ECT is reserved for life-threatening/refractory severe depression (or severe catatonia) — its main side-effect is retrograde/anterograde amnesia.

Monitor & prognosis

PHQ-9 response; suicide risk; SSRI early adverse effects (anxiety, GI, hyponatraemia esp. elderly); discontinuation symptoms on stopping (taper).

Most recover; recurrence common — risk rises with each episode.

Source: NICE CKS Depression (2025) / NG222