The following document was written by Dr Vipul Rastogi, MBBS; DCP (Ireland); MRCPsych (UK) Speciality Registrar, Hampshire Partnership Trust, UK, March 2008.
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Mood Disorders include a large group of related disorders commonly seen by Psychiatrists. The signs and symptoms are different in different age groups and understanding of socio-cultural backgrounds is very important when looking at treatment options.

Mood Disorders include

I would like to think of mood disorders as lying on a continuum.

mood disorders

Mood Disorders- Major Depression

In past depression was described as anyone experiencing hopelessness, helplessness and worthlessness. Although helpful but it lead to the over use of the word depression and anybody having a bad day would say that they are depressed. Therefore, there are now fixed diagnostic guidelines for depression.

There are two classification systems used currently

1) International Classification of Diseases-10 ( ICD-10) – WHO Classification

2) Diagnostic and Statistical Manual of Mental Disorders (DSM-IV)

Although both classification systems have their merits and drawbacks, Psychiatrists in UK tend to use ICD-10 more commonly and we would be discussing the topic with regards to ICD-10.


Depression is one of the most common problems that people present to their GP with. The Lifetime rates vary between various studies but would appear to be between 4-30% with a true value around 15%. There is almost 2 fold more incidence of major depression in females as compared to males in different cultures.

The mean age of onset is about 27 with higher rates found in divorced and unemployed population.

There is also a very high co morbidity with anxiety and substance misuse disorders. Almost 15% of medical inpatients would have features of a depressive disorder.

Depression is also one of the leading causes of morbidity and loss of work productivity.


There are several theories that try to explain the genesis of depression but what is accepted is that the cause of depression is multi-factorial. Listed below are some major factors that are considered to be the cause of depression. The list below is not exhaustive and readers are advised to read a standard textbook for complete list.

Genetic Causes

Mood Disorders tend to run in families and this has been proved by Twin Studies.

Biological Causes

Biogenic Amines- There are two major amines that have been implicated in causation of depression and other amines are still being investigated. The lack of Serotonin and Noradrenaline availability at receptor sites in the brain leads to depression.

Neuroendocine Regulation- A correlation between the hyper secretion of cortisol and depression is one of the oldest theories of depression. Hypothyroidism is one of the most common disorders found in depression and should always be looked for.

Psychosocial Factors

Adverse life events and environmental factors can trigger depression. Life events that lead to feelings of entrapment and humiliation may be particularly relevant.

Cognitive Theory

According to cognitive theory people with depression tend to form cognitive distortions which include developing negative views about self, environment and future.

Clinical Features of Depression

The central features of depression are having
Features 1-3 are classified as core symptoms and two of these three have to be present for at least two weeks to make a diagnosis of depression.

Other factors to look at are psychomotor activity, symptoms of anxiety, substance misuse and psychosis.

Diagnostic Criteria – ICD 10

Mild Depression- At least 2 out of the three core symptoms for two weeks with at least 2 of the remaining symptoms.

Moderate Depression- At least 2 out of the three core symptoms for 2 weeks with at least 3 of the remaining symptoms.

Severe Depression- At least 2 out of the three core symptoms for two weeks with at least 4 of the remaining symptoms.

Severity of symptoms and degree of functional impairment also guides classification.

Differential Diagnosis

Depression has to be differentiated from normal sadness, as we talked before somebody having a bad day doesn’t necessarily have depression.

Other important differential diagnosis are


Psychiatry is very different from other medical fields and we would divide our investigations in biological, social and psychological investigations.


Basic blood investigation including full blood count, liver function test, urea and electrolytes. These are to exclude any organic causes of low mood. Thyroid function tests and blood sugars are also important as hypothyroidism and diabetes can both predispose and precipitate depression.

Most psychiatrists would also consider CT scan if presentation is following a head injury or the patient has symptoms of confusion and dementia.

ECG is also particularly important because some antidepressants can have effect on QTc intervals.


Social investigations would include looking at their support structure i.e. family, benefits, housing and debts. Also investigating difficulties with children, getting collateral information from partner, parents and other relevant professionals involved in the patients care. All this has to be done with consent from the patient.


This would include looking at their upbringing, bereavement and also completing some mood and anxiety scales for baseline and to judge progress and improvement.

Various treatment modalities would be considered in another section.


Dr Vipul Rastogi, MBBS; DCP (Ireland); MRCPsych (UK)

speciality Registrar, Hampshire Partnership Trust, UK


1) Shorter Oxford Textbook of Psychiatry, Fourth Edition, Michael Gelder et al.

2) Concise Textbook of Psychiatry, Second Edition, Kaplan and Sadock

3) The ICD-10 Classification of Mental and Behavioural Disorders- WHO


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