14th February 2025

A 42-year-old man has recently returned from a stressful business trip to Singapore feeling low and lethargic.

A 42-year-old man has recently returned from a stressful business trip to Singapore feeling low and lethargic. He is struggling to concentrate during business meetings and feels hopeless about the future. He has noticed that he wakes up a few hours earlier than normal and has been losing weight. As this has been going on for 3 weeks, he decides to see his GP.

His GP organises some blood tests to rule out an organic cause of his symptoms:

Haemoglobin 126 g/L (130-180)

White Cell Count 5.9 x10⁹/L (3.6-11)

Neutrophils 2.2 x10⁹/L (1.8-7.5)

Platelet Count 340 x10⁹/L (140-400)

Sodium 143 mmol/L (135-145)

Potassium 4.1 mmol/L (3.5-5.3)

Urea 5.4 mmol/L (2.5-7.8)

Creatinine 99 micromol/L (59-104)

eGFR 70

TSH 3.2 mU/L² (0.4-4)

Free T4 18 pmol/L (9-24)

Vitamin B12 600 pg/ml (180-1000)

Folate 13 ng/ml (>4)

Which of the following is a core symptom of a depressive episode?

Select the SINGLE most appropriate option from the list below. Select ONE option only.