Exploring the different types of mood disorder

There are a variety of mental health conditions that can lead to mood abnormalities, and it's extremely important to diagnose them correctly, as that informs the appropriate treatment, and impacts on a person’s recovery. In this article, we discuss the significant overlap between different mood disorders, which adds to the complexity of diagnosis and treatment.

Mood disorders are the most common type of mental health problem, with a prevalence of about 19.7% in adults, according to the UK Mental Health Foundation, with a higher rate in women than men. In the UK, about 13.7% of adults screen positively for a personality disorder and 2% for bipolar disorder.

The different types of mood disorder defined

Diagnosis of a depressive disorder requires two of the three core symptoms, with an addition of two of the four other symptoms that would distinguish between mild, moderate and severe. The duration of symptoms should be at least 2 weeks, but in some cases, can last much longer.

Some of the different types of mood disorder include:

Dysthymia

The difference between depressive disorder and dysthymia is that the symptoms in dysthymia never, or very rarely, reach the criteria to diagnose depression. However, the duration is chronic and long-standing. Dysthymia therefore, can also be known as a ‘depressive personality disorder’.

Pseudodementia

This is a depressive illness that's commonly mistaken for dementia, and occurs mainly in the elderly population. This is because the symptoms of depression mimic dementia, with increasing forgetfulness, becoming withdrawn, and other executive function deficits. The differentiation becomes clearer with MRI scans, and other clinical features and history, but it's worth noting that depression and dementia can commonly co-exist.

Bipolar disorder

To diagnose bipolar disorder, a person has to have at least one episode of mania or hypomania, and at least another episode of a mood disorder. If someone has only had hypomanic episodes, that never reached full blown mania, then this is classed as a bipolar type 2. For example, a person who's had several depressive episodes, and several hypomanic episodes, would be diagnosed as bipolar type 2, and someone who's had one depressive episode and one manic episode, would be bipolar type 1. So it's not the length of illness, or the frequency of episodes, but the severity of the manic symptoms that determine the type of bipolar disorder.

Hypomania

To diagnose a manic episode, manic symptoms should have been present for at least 1 week, and have caused significant disruption to the person’s life. Hypomania differs from mania in that the duration of symptoms are less than a week, and the severity is less. Also, psychotic symptoms like grandiose delusions will only be experienced in mania and not hypomania.

Pre-menstrual dysphoric disorder (PMDD)

This is a mood disorder related to the menstrual cycle, and therefore is only experienced 1 or 2 weeks before periods. It has symptoms of depression and anxiety and sometimes suicidal feelings. The only difference from others, is the woman starts feeling better once the period starts and by the time period is finished, the symptoms have disappeared.

Mixed affective episode

This is a very interesting, although confusing, picture of bipolar disorder. A person will show symptoms of both depression and mania or hypomania at the same time. For example, they have a predominantly depressed mood, but they will also have co-existing pressured speech, flight of ideas and over-activity. On the other hand, they may have an elated mood and grandiosity, but might have low energy and a lack of libido, for example. In order to diagnose a mixed affective episode of bipolar disorder, these mixed symptoms have to last 2 weeks.

Schizoaffective disorder

This is another category of mental illness in which the symptoms of depression or mania co-exist with at least one or two symptoms of schizophrenia, in at least one episode of their illness.

Cyclothymia

Cyclothymia is more prevalent within the general population, and often goes undiagnosed, or perhaps incorrectly diagnosed for a personality disorder, or another type of mood disorder, due to the nature of its symptoms. It's characterised by mild elevation or depression of mood, which doesn't satisfy the diagnostic criteria for depression or mania/hypomania. Some people find the high episodes within cyclothymia very enjoyable and productive, as it doesn't impact on their day-to-day wellbeing.

What can be done in a GP consultation?

It's really important to tease out the appropriate diagnosis, by taking a good history, and asking patients to keep a mood diary. Treatment varies depending on diagnosis, with certain mood disorders needing longer term medication and psychological therapies, compared to others.

If it's deemed necessary, the patient may benefit from an inpatient stay at a specialist hospital, where a full diagnostic service can be provided, followed up with the appropriate care plan.

Certain therapies which are known to help in the treatment of mood disorders can also be discussed. They include:

• Cognitive behavioural therapy (CBT)
• Dialectical behaviour therapy (DBT)
• Cognitive analytic therapy (CAT)

These therapies are directed towards specific mood disorders, which are discussed in more detail in this article. If these approaches are matched with the appropriate medical treatment, they can significantly improve quality of life and prognosis of your patient.

The symptoms to look out for when diagnosing mood disorders are as follows:

Depressive symptoms

Core

• Depressed mood
• Anhedonia (inability to feel pleasure in normally pleasurable activities)
• Reduced energy, increased fatigue

Other

• Reduced concentration and attention
• Reduced self-esteem and confidence
• Ideas of guilt and unworthiness
• Bleak and pessimistic views of the future
• Ideas or acts of self-harm or suicide
• Disturbed sleep
• Early morning awakening
• Diurnal variation of mood
• Diminished appetite
• Weight loss
• Loss of libido
• Psychomotor retardation or agitation

Manic symptoms

• Elevated mood
• Elation
• Increased energy and activity
• Increased sociability, disinhibition and over-familiarity
• Poor attention and concentration
• Pressured (rapid) speech
• Reduced need for sleep
• Grandiose ideas
• Overspending

The various types of mental health problems that could result in disturbances of mood are as follows:

• Depressive disorder
• Mania
• Bipolar disorder (type 1 and 2)
• Cyclothymia
• Personality disorders
• Dysthymia
• Substance misuse
• Pseudodementia
• Schizoaffective disorder

Potential causes of a mood disorder

Various genetic, biological, environmental, and other factors have been associated with mood disorders.

It's interesting to mention that there might be a family history associated with the development of mood disorders, and some people can go on to develop bipolar disorder in later life due to trauma, major life changes or experiencing severe physical illness.

Another potential cause of a mood disorder is substance misuse. Alcohol is a depressant, and while it causes temporary elevation of mood for a lot of us, chronic and excessive use can result in depression. Similarly, certain drugs, mostly stimulants, like amphetamines or cocaine, can mimic features of a manic episode. Long-term use of cannabis can cause cannabis a-motivational syndrome, which also mimics depression.