3.3 Diagnosing major depression (MD)
Between ordinary low mood and serious depression lie a range of depressive experiences of varying degrees of severity – that is, there is a continuum. One important issue for diagnostic schemes is whether to draw a line between ‘ordinary sadness’ and serious depression and, if so, where this line should be drawn.
DSM-IV-TR (and ICD-10) diagnostic systems are categorical – that is, they are used to decide whether a particular named disorder is present or not present. In effect, they draw a line through a continuum of experience. It is a bit like deciding that all men over the height of 5 ft 6 in (1.68 m) fall into the category ‘tall’, while all those under this height fall into the category ‘short’.
The DSM-IV-TR criteria for MD are shown in Box 3. Depression that does not meet the criteria is categorised as subclinical depression, while any depression that does meet the criteria is categorised as clinical depression.
As you look at Box 3 below, think back to Lewis Wolpert’s account of his depression (Vignette 1), and consider how the criteria below relate to his experience.
Box 3 Diagnostic criteria for major depressive episode
(Adapted from DSM-IV-TR (APA, 2000))
The American Psychiatric Association suggest a diagnosis of depression if, during the same 2-week period, a person experiences five (or more) of the following symptoms, which must include either or both of the two primary symptoms:
The primary symptoms are:
- persistent feelings of sadness or anxiety
- loss of interest or pleasure in usual activities
The secondary symptoms are:
- changes in appetite that result in weight losses or gains not related to dieting
- insomnia or oversleeping
- loss of energy or increased fatigue
- restlessness or irritability
- feelings of worthlessness or inappropriate guilt
- difficulty thinking, concentrating or making decisions
- thoughts of death or suicide or attempts at suicide
Note: symptoms should not be counted if:
- A.They are the direct physiological effects of a substance (drug of abuse, or medication) or a medical condition (e.g. hypothyroidism)
- B.They would be better accounted for by bereavement (i.e. the loss of a loved one).
Activity 3 Using diagnostic criteria
Considering Lewis Wolpert’s depressive episode, and the criteria in Box 3:
- a.Which of the criteria were clearly or probably met in Wolpert’s account?
- b.Are there any criteria that there might be some uncertainty about?
- c.Were there any experiences in Wolpert’s account that are not mentioned in the criteria?
- a.All of criteria 1–9 appear to have been met.
- b.It is interesting that a change of drug preceded Wolpert’s episode; he also had a medical condition (atrial fibrillation). We don’t have any information about the extent to which these were responsible for any of the symptoms he experienced – so we don’t know if item (A) in the criteria in Box 3 applied or not.
- c.He mentions physical (somatic) symptoms and deteriorating memory (though the latter could perhaps be covered by criterion 8).
In real life, low mood is a continuum – people can be mildly, moderately or seriously depressed. Scales other than the DSM are used to assess the level of depression on a continuum. The Beck Depression Inventory is one such scale.
Can you think of a situation in which it would be useful to have a scale such as the BDI?
In studies where researchers are interested in the efficacy of a particular drug treatment or other intervention, they need to assess the severity of the depression before and after the treatment or intervention. Scoring on a scale such as the BDI would allow such an assessment.
Activity 4 Diagnosing major depression
Jean has lost her beloved husband and consequently has been feeling very low for the last two weeks. Bill has lost his job and is feeling similarly low. Symptoms 1, 2, 3, 4, 5 and 8 in Box 3 definitely apply to both Jean and Bill. Are they equally likely to be diagnosed as suffering major depression (MD)? Explain your answer.
No, they are not. Jean is unlikely to be diagnosed with MD because criterion B in Box 3 specifically excludes those whose symptoms may be linked to the loss of a loved one – which would appear to apply in her case. However, Bill would be diagnosed with MD, as job loss and consequent feelings of bereavement are not allowed for in the DSM-IV-TR criteria for MD.