Mental Health

Depression: UK Online Doctor Diagnosis & Treatment Guide

8 min readLast reviewed 24 April 2026

Educational information — not medical advice.

This article was prepared by the OnlineDoctor24 editorial team and reviewed for factual accuracy against UK clinical guidance (NHS and NICE). It is not written by a doctor and does not replace personal medical advice. For symptoms specific to you, book an online doctor consultation.

Key points

  • Depression is more than feeling sad — it's persistent low mood lasting weeks, with loss of interest, sleep changes and low energy.
  • First-line: lifestyle measures, CBT and (if moderate or worse) an SSRI antidepressant.
  • PHQ-9 is the standard UK assessment tool.
  • Most antidepressants take 4–6 weeks for full effect.
  • An online doctor can assess, prescribe and refer to therapy.

Symptoms

  • Persistent low mood for 2+ weeks
  • Loss of interest or pleasure (anhedonia)
  • Fatigue, reduced energy
  • Sleep changes (insomnia or oversleeping)
  • Appetite/weight changes
  • Feelings of guilt, worthlessness, hopelessness
  • Difficulty concentrating
  • Thoughts of self-harm

Self-care

  • Behavioural activation — small daily activities, even when motivation is low.
  • Regular movement and sleep.
  • Limit alcohol — it worsens depression.
  • Connect with one trusted person.

Talking therapies

NHS Talking Therapies offers free CBT. Self-refer online via your local service. Private CBT and counselling provide faster access.

Antidepressants

  • First line: sertraline 50 mg, citalopram 20 mg, escitalopram 10 mg.
  • Alternative: mirtazapine if sleep/appetite poor; venlafaxine for severe cases.
  • Continue for at least 6 months after recovery; longer if recurrent.
  • Taper slowly — never stop abruptly.

Red flags — when to seek urgent help

Call 999 or go to A&E if you experience any of the following:

  • Active thoughts of suicide or self-harm — call 999 or Samaritans 116 123
  • Plans to end your life — go to A&E
  • Severe agitation or psychotic symptoms

Frequently asked questions

Common questions UK patients ask about depression.

How an online doctor can help

This article is for general information only and does not replace personal medical advice from a qualified doctor. Content is reviewed against UK NHS and NICE guidance by the OnlineDoctor24 editorial team and is not authored by a medical doctor. If your symptoms worsen or you are unsure, please book a consultation with a GMC-registered GP.

See a UK GP about this today

Same-day video or phone consultations with GMC-registered GPs. Prescriptions, sick notes and referrals when clinically appropriate.