Diagnosis of Depression
Updated: 6 February 2019
In ordinary, everyday discourse, nearly any mood with some element of sadness may be called ‘depressed’. However, for depression to be termed Clinical Depression, it must reach criteria which are generally accepted by clinicians; it is more than just a temporary state of sadness. Generally, when symptoms last 2 weeks or more and are so severe that they interfere with daily living (failure to function adequately), someone can be said to be suffering from Clinical Depression.
Clinical Depression affects about 16% of the population at one time or another in their lives. The mean age of onset from a number of studies is in the late 20s. There a gender difference in incidence as roughly twice as many women as men report or receive treatment for Clinical Depression, though the gap is shrinking and this difference disappears after menopause. Up to 25% of females will be diagnosed at some point in their life and up to 12% of men. At any one point in time it is estimated 9% of women and 3% of men are clinically depressed. According to the World Health Organisation (2018): “Depression is the leading cause of disability worldwide, and is a major contributor to the overall global burden of disease.”
There are, however, issues around the diagnosis and classification of Depression.
The DSM view
The Diagnostic & Statistical Manual of Mental Disorders (DSM) of the American Psychiatric Association is one of the 2 leading psychiatric classification systems in the world. Using its terminology, someone with a major depressive disorder can, by definition, be said to be suffering from Clinical Depression.
Just to be clear what we mean by Clinical Depression, it is pertinent to refer to the symptoms described in the DSM-5 (2015). It lists the following:-
- Depressed mood most of the day, nearly every day, as indicated by either subjective report (eg: feels sad, empty, hopeless) or observation made by others (eg: appears tearful). (Note: In children and adolescents, can be irritable mood.)
- Markedly diminished interest or pleasure in all, or almost all, activities most of the day, nearly every day (as indicated by either subjective account or observation.)
- Significant weight loss when not dieting or weight gain (eg: a change of more than 5% of body weight in a month), or decrease or increase in appetite nearly every day. (Note: In children, consider failure to make expected weight gain.)
- Insomnia or hypersomnia nearly every day
- Psychomotor agitation or retardation nearly every day (observable by others, not merely subjective feelings of restlessness or being slowed down)
- Fatigue or loss of energy nearly every day
- Feelings of worthlessness or excessive or inappropriate guilt (which may be delusional) nearly every day (not merely self-reproach or guilt about being sick)
- Diminished ability to think or concentrate, or indecisiveness, nearly every day (either by subjective account or as observed by others)
- Recurrent thoughts of death (not just fear of dying), recurrent suicidal ideation without a specific plan, or a suicide attempt or a specific plan for committing suicide
5 or more of the above symptoms must be persistent for at least 2 weeks and the symptoms causing clinically significant distress or impairment in social, occupational, or other important areas of functioning for diagnosis to be made. Additionally, the symptoms must not be attributable to any kind of substance abuse or better explained by any other medical or psychiatric condition.
DSM-5 represents a shift from the previous edition, DSM-IV-TR (2000). This required the sufferer to have a depressed mood and/or loss of interest or pleasure. For a diagnosis it was sufficient to have either of these symptoms in conjunction with 4 of a list of other symptoms that included:-
- Feelings of overwhelming sadness or fear, or seeming inability to feel emotion
- Marked decrease of interest in pleasurable activities
- Changing appetite and marked weight gain or weight loss
- Disturbed sleep patterns, either insomnia or sleeping more than normal
- Changes in activity levels, restless or moving significantly slower than normal
- Fatigue, both mental and physical
- Feelings of guilt, helplessness, anxiety, and/or fear
- Lowered self-esteem
- Decreased ability to concentrate or make decisions
- Thinking about death or suicide
The diagnosis did not require “loss of interest in life, anhedonia“. Likewise, “lack of energy and motivation” was not at all a required symptom of a major depressive episode. There were reported numerous problems with diagnosis under DSM-IV-TR, as there still to some degree under DSM-5. Guilt, irritability, aches and pains and, in women, changes in menstrual patterns can be seen as symptomatic or not symptomatic of Depression by different clinicians. Andrew Solomon in his book ‘The Noonday Demon’ (2001, p20) was scathing about the DSM-IV list of symptoms, saying it was: “entirely arbitrary [and] having slight versions of all the symptoms may be more of a problem than having severe versions of two symptoms”. The latest revision of DSM seeks, in part at least, to address concerns such as those of Solomon.
Several variations or subtypes of Major Depression are classified, eg::-
- Atypical Depression is characterised by mood reactivity (‘paradoxical anhedonia’) and positivity, significant weight gain or increased appetite (‘comfort eating’), excessive sleep or somnolence (hypersomnia), a sensation of heaviness in limbs known as ‘leaden paralysis’, and significant social impairment as a consequence of hypersensitivity to perceived interpersonal rejection. (Difficulties in measuring this subtype have led to questions of its validity and prevalence.)
- Melancholic Depression is characterised by a loss of pleasure (anhedonia) in many activities, a failure of reactivity to pleasurable stimuli, a quality of depressed mood more pronounced than that of grief or loss, a worsening of symptoms in the morning hours, early-morning waking, psychomotor retardation, excessive weight loss (not to be confused with anorexia nervosa), or excessive guilt
- Psychotic Major Depression, or simply ‘Psychotic Depression’, is the term for a major depressive episode, in particular of melancholic nature, wherein the patient experiences psychotic symptoms such as delusions or, less commonly, hallucinations. These are most commonly mood-congruent (content coincident with depressive themes)
- Catatonic Depression is a rare and severe form of major depression involving disturbances of motor behaviour and other symptoms. Here, the person is mute and almost stuporose, and either is immobile or exhibits purposeless or even bizarre movements. Catatonic symptoms can also occur in Schizophrenia or a manic episode or can be due to Neuroleptic Malignant Syndrome
- Postpartum Depression refers to the intense, sustained and sometimes disabling depression experienced by women after giving birth. Postpartum Depression, which affects 10–15% of women, typically sets in within 3 months of giving birth and can last as long as 3 months. It is quite common for women to experience a short-term feeling of tiredness and sadness in the first few weeks after giving birth; however, Postpartum Depression is different because it can cause significant hardship and impaired functioning at home, work or school, as well as, possibly, difficulty in relationships with family members, spouses or friends, or even problems bonding with the newborn child. Women with personal or family histories of mood disorders are at particularly high risk of developing postpartum depression.
- Premenstrual Dysphoric Disorder (PMDD) is a severe and disabling form of Premenstrual Syndrome affecting 3–8% of menstruating women. The disorder consists of a “cluster of affective, behavioural and somatic symptoms” that recur monthly during the luteal phase of the menstrual cycle. PMDD was added to the list of depressive disorders in the DSM in 2013. The exact pathogenesis of the disorder is still unclear and is an active research topic.
- Seasonal Affective Disorder (SAD), also known as ‘winter depression or winter blues, is a specifier. Some people have a seasonal pattern, with depressive episodes coming on in the autumn or winter, and resolving in spring. The diagnosis is made if at least 2 episodes have occurred in colder months with none at other times over a two-year period or longer. It is commonly hypothesised that people who live at higher latitudes tend to have less sunlight exposure in the winter and therefore experience higher rates of SAD, but the epidemiological support for this proposition is not strong (and latitude is not the only determinant of the amount of sunlight reaching the eyes in winter). SAD is also more prevalent in people who are younger and typically affects more females than males.
- Dysthymia is a condition related to Major Depression, where the same physical and cognitive problems are evident, but they are not as severe and tend to last longer (usually at least 2 years).
The ICD view
The International Classification of Diseases of the World Health Organisation is the other major classification system – though it attempts to log all illnesses worldwide, both mental and physical. Diagnostic criteria for Depression in ICD-10 (1996) uses a list of 10 depressive symptoms.
Firstly, the 3 ‘key symptoms’ are:-
- persistent sadness or low mood
- loss of interests or pleasure
- fatigue or low energy
At least one of these, most days, most of the time for at least 2 weeks.
There is a list of secondary symptoms…
- disturbed sleep
- poor concentration or indecisiveness
- low self-confidence
- poor or increased appetite
- suicidal thoughts or acts
- agitation or slowing of movements
- guilt or self-blame
Where ICD-10 differs significantly from DSM is that it uses the lists to estimate the degree of Depression – as per
- not depressed (fewer than 4 symptoms)
- mild depression (4 symptoms, including up to 2 of the key symptoms)
This person may be able to carry on with most of their daily functions.
- moderate depression (5-6 symptoms, including at least 2 of the key symptoms)
This person will have difficulty carrying out their daily functions.
- severe depression (7 or more symptoms, including all 3 key symptoms – with or without psychotic symptoms)
Symptoms should be present for a month or more and every symptom should be present for most of every day.
People with this level of Depression have symptoms that are marked and distressing, mainly the loss of self-esteem and feelings of guilt and worthlessness. Suicidal thoughts and actions are common. Psychotic symptoms such as delusions and, less commonly, hallucinations may occur – though they may not be mood dependent.
There are similar subtypes to those found in DSM.
At the time of writing ICD-11 has been completed and is to be put to the membership of the World Health Organisation for official adoption in May 2019.
Changes to the criteria for Depression include the omission of ‘fatigue or low energy’ from the key symptoms and their inclusion in a ‘neurovegetative’ cluster. Although this is in line with definitions of depressive episodes in DSM-5, the idea of specific clusters of depressive symptoms is unique to the ICD-11 revision. However, requirements for a threshold of 5 symptoms, one of which is from the ‘affective cluster’, are similar to DSM-5 and thus different to ICD-10. In addition, ‘impairment of role-function’ has been added as an essential feature. In the ICD-10, functional impairment was not included in the definition of depression because of concerns about cultural factors confounding social performance. However, the ICD-11 Mood Disorders Working Group chose to include impaired role-function as an essential feature because of the evidence linking severity of depression with functional decline and the well-known fallacies of relying solely on symptom counts to diagnose Depression
Impaired cognitive function
Poor cognitive function is a recognised feature of Depression and is a diagnostic criteria for both DSM and ICD.
One study which demonstrates impaired cogntive function is that of Myriam Gallardo Perez et al (1999) who compared selective attention in depressed persons with non-depressed participants in whom a sad mood had been induced by playing miserable music and recalling unhappy memories. Participants were given a Stroop Task involving unhappy stimuli. This involved naming the ink colour in which each of a sequence of words was written. The task required the participants to pay attention to the ink colour rather than the words. (Most people find this difficult and the words they pay attention to can reveal much about their state of mind.) The major depressive group, but not the sad mood-induced participants, paid significantly more attention to unhappy words in the Stroop Task. This indicates that attention works differently in Depression.
Depression in children
This is not as obvious as it is in adults; symptoms children demonstrate include:-
- sadness or a low mood that doesn’t go away
- being irritable or grumpy all the time
- not being interested in things they used to enjoy
- feeling tired and exhausted a lot of the time
The child may also:-
- have trouble sleeping or sleep more than usual, sometimes with nightmares
- not be able to concentrate
- interact less with friends and family
- be indecisive
- not have much confidence
- eat less than usual or overeat
- have big changes in weight
- seem unable to relax or be more lethargic than usual
- talk about feeling guilty or worthless
- feel empty or unable to feel emotions (numb)
- problems with behaviour or grades at school where none existed befo
- have thoughts about suicide or self-harming
- actually self-harm, for example, cutting their skin or taking on overdose
In older children and adolescents, an additional indicator may be the use of drugs or alcohol. Moreover, depressed adolescents are at risk for further destructive behaviours, such as eating disorders and self-harm.
Facing up to Depression
It is hard for people who have not experienced Clinical Depression, either personally or by regular exposure to people suffering it, to understand its emotional impact and severity. It’s easy to meta-state it instead as being similar to “having the blues” or “feeling down”. As the DSM and ICD symptoms above indicate, Clinical Depression is a syndrome of interlocking symptoms which goes far beyond sad or painful feelings. A variety of biological indicators, including measurement of neurotransmitter levels, have shown that there are significant changes in brain chemistry and an overall reduction in brain activity.
Some of the key factors which may interlock to produce the symptoms of Depression are considered in Can vMEMES cause Clinical Depression..?
One consequence of a lack of understanding of its nature is that depressed individuals are often criticised by themselves and others for not making an effort to help themselves. However, the very nature of Depression alters the way people think and react to situations to the point where they may become so pessimistic that they can do little or nothing about their condition.
Due to this profound and often overwhelmingly negative outlook, it is imperative that the depressed individual seek professional help. Untreated Depression is typically characterised by progressively worsening episodes separated by plateaus of temporary stability or remission. If left untreated it will generally resolve within 6 months to 2 years although occasionally Depression becomes chronic and lasts for many years or indefinitely. In many cases (but not all) treatment can shorten the period of distress to a matter of weeks. While depressed, the person may damage themselves socially (eg: the break up of relationships), occupationally (eg: loss of a job), financially and physically. Treatment of Depression can significantly reduce the incidence of this damage, including reducing the risk of suicide which is otherwise a common and tragic outcome. For all of these reasons, treatment of Clinical Depression is seen by many as very useful and at times life saving.
Matthew Johnstone’s video below (copyright © 2005 World Health Organisation) provides an insight into what having Depression is like and how professional help can assist with reducing Depression.