Clinical depression in the ICD
- Unipolar depression, also called clinical depression, is a recognised mental health condition with a defined set of symptoms.
- A doctor diagnoses it using the International Classification of Diseases (ICD), now in its eleventh edition, ICD-11.
- The judgement rests on which symptoms are there, how severe they are and how long they have lasted.
Key Idea
- Clinical depression is diagnosed when at least five of the listed symptoms have been present nearly every day for two weeks, with at least one of them a change in mood.
- The symptoms cover feeling, thinking and the body, so broken sleep and a lost appetite count towards the total just as low mood does.
- The symptoms also have to make everyday functioning genuinely harder, at school, at work or in relationships.
The three clusters of symptoms
Definition
Unipolar depression
A mental health condition, also called clinical depression, in which a person has a persistent low mood and loss of interest, without the periods of high mood seen in bipolar depression.
- Affective symptoms
- Depressed mood is present for most of the day, on most days, and does not lift for long even when something good happens.
- Loss of interest or pleasure: the things that used to matter, such as football, music or seeing friends, stop feeling worth doing.
- Cognitive and behavioural symptoms
- Reduced concentration makes following a lesson or holding a conversation take far more effort than it used to.
- Beliefs of low self-worth often come with heavy guilt about things that were never the person's fault.
- Hopelessness about the future means nothing ahead seems likely to get better.
- Recurrent thoughts of death or of suicide are on the ICD list, and a person reporting them needs prompt support.
- Neurovegetative symptoms
- Disrupted sleep can mean broken nights and waking early, or sleeping far more than usual.
- Appetite or weight change counts in either direction, up or down from what is normal for that person.
- Reduced energy and fatigue make ordinary tasks such as getting up or replying to a message feel exhausting.
- Psychomotor change shows either as restless agitation or as noticeably slowed movement and speech.
Example
- Picture someone booking a GP appointment because for six weeks they have woken at four every morning, stopped watching the football they loved and cannot get through a page of revision.
- That is low mood, loss of interest, disrupted sleep and reduced concentration, so four symptoms are already on the ICD list.
- Most people who reach that appointment do get better with support and treatment.
Unipolar depression, bipolar depression and everyday sadness
- Unipolar depression involves low mood only, with no episodes of unusually high mood.
- Bipolar depression differs because low periods alternate with manic periods of very elevated mood, energy and activity.
- Everyday sadness is milder, usually has a clear cause and passes within days.
- Everyday sadness also lifts when something good happens.
Common Mistake
- Clinical depression is not the same as feeling sad, because a diagnosis rests on the ICD characteristics.
- Unipolar and bipolar are easily muddled, and only bipolar includes the swings up into high mood.
Reaching a diagnosis
Definition
ICD
The International Classification of Diseases, a manual published by the World Health Organization that lists the symptoms doctors check when they diagnose a condition such as depression or addiction.
- Number: ICD-11 asks for at least five of the symptoms above, at least one of them from the affective cluster.
- Duration: those symptoms have to be present nearly every day for at least two weeks.
- Impact: they must cause real difficulty with everyday functioning, such as school, work or relationships.
- Severity: more symptoms and greater severity move the diagnosis from mild towards moderate and then severe.
- A single episode is recorded differently from recurrent depressive disorder, where a person has had earlier episodes and recovered in between.
- The ICD is published by the World Health Organization and is the manual used in the UK.
Note
- The ICD is the manual used in the UK and the DSM is the American equivalent, so a threshold quoted from one may not match the other.
- Recurrent depressive disorder describes a pattern of episodes with recovery in between, so recovery is built into the way the condition is recorded.
- Anyone with recurrent thoughts of death or suicide should be encouraged to speak to a GP or a helpline straight away.
Turning this into marks
- When two symptoms are asked for, make them genuinely separate rather than one symptom rephrased.
- Name the ICD, because a description that could have come from any manual does not secure the knowledge mark, and the DSM is the American manual rather than the UK one.
- Give the threshold of at least five symptoms nearly every day for at least two weeks whenever a question asks how depression is diagnosed.
- The mark most often lost is describing bipolar depression when the question named unipolar depression.
Self review
- Name the two affective symptoms in ICD-11.
- Give three neurovegetative symptoms of clinical depression.
- How many symptoms, and over how long, does ICD-11 require?
- How does unipolar depression differ from bipolar depression?
- Give two ways clinical depression differs from everyday sadness.
