Next Lesson - Psychosis
Core
This article will focus on disorders of mood, including depression, mania, hypomania, and bipolar disorder.
Depression is a condition of low mood that affects 5% of adults worldwide (source).
For a diagnosis of depression there must be at least 2 of the core symptoms of depression present for 2 or more weeks, usually alongside additional psychological or physical symptoms. There are 3 core symptoms of depression namely:
- Low mood
- Lack of energy
- Lack of enjoyment or interest in things the patient would usually enjoy (also known as anhedonia)
Depression is also associated with a number of ‘biological’ or ‘somatic’ symptoms:
- Reduced sleep or insomnia, usually characterised by early morning waking
- Hypersomnia - increased sleep
- Reduced appetite
- Psychomotor retardation
- Reduced libido (sex drive)
Unfortunately, the precise causes of most mental illnesses have not been identified at this time. However, a collection of risk factors has been identified, and if multiple are present simultaneously, this can increase the risk of mental illness. These can be categorised into predisposing factors (things the patient cannot change), perpetuating or maintaining factors (things in the patient’s life now that encourage mental illness), and precipitating factors (an event that ‘pushes’ the patient into mental illness).
Predisposing Factors:
- Genetics - a family history of depression makes it more likely
- Childhood experiences - abuse, loss of a parent, bullying
Perpetuating Factors:
- Stressful job or unemployment
- Financial strain
- Substance misuse
- Relationship difficulties
- Housing uncertainty
Precipitating Factors:
- Life events often related to loss - death of a loved one, end of a relationship, declining physical health
Adjustment Reactions vs Depression
It is important to differentiate between a normal response to a distressing event and clinical depression, especially because the traumatic event may be the precipitating factor for depression AND result in a normal adjustment reaction.
An adjustment reaction follows a traumatic event, with fluctuating symptoms including feelings of anger and frustration. There are no particular disturbances to sleep, appetite or energy levels.
Clinical depression is a condition of low mood, lack of energy and lack of enjoyment that comes on more gradually and must last for a period of 2 weeks or more. Lack of sleep (insomnia), poor appetite and lack of libido are common.
If an adjustment reaction persists and there are symptoms of depression present the reaction may have triggered the development of depression.
The table below describes the symptoms of both, to show the differences between these two conditions.
Table - The differences between adjustment reaction and clinical depression
There are many physical illnesses that can present similarly to depression, and it is therefore important to investigate for and treat these before diagnosing a patient with depression:
- Hormone disturbances such as thyroid dysfunction
- Deficiency of vitamins such as vitamin B12
- Kidney disease
- Alcohol and drug misuse
Mania and hypomania are conditions which both involve elevated mood. Mania must be present for at least 1 week (or any duration if hospitalisation is required), whereas hypomania must be present for at least 4 days. About 16 in 1000 people will experience mania at some point in their life (source).
Other than elevated mood symptoms include:
- Increased energy
- Pressure of speech (fast rate of speech)
- Reduced sleep
- Flight of ideas - a thought disorder in which thoughts change topic very quickly
- Loss of social inhibitions
- Inflated or grandiose self-esteem
Hypomania is considered to be a less severe version of mania. The main differentiating features are that mania causes marked functional impairment and may include psychotic symptoms such as hallucinations or delusions, whereas hypomania does not cause severe impairment and does not include psychotic symptoms.
Bipolar disorders involve episodes of mania or hypomania, with the depressive history helping distinguish the subtypes. Under the DSM-5-TR framework, bipolar I and bipolar II have different episode requirements; a universal two-episode rule is inappropriate.
Bipolar I requires at least one manic episode; major depression is common but is not required. Bipolar II requires at least one hypomanic episode and at least one major depressive episode, with no history of mania. Episodes must meet diagnostic criteria and not be better explained by substances or another medical condition.
Bipolar disorder is relatively common in the UK, with 1 in 100 people being diagnosed with bipolar disorder at some point throughout their life (source).
The DSM-5-TR subtype requirements can be summarised as follows:
- Bipolar I - At least one manic episode; a depressive episode is not required
- Bipolar II - At least one hypomanic episode and one major depressive episode, with no manic episode
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