A nosological review of depressive disorders based on observations in clinical practice,Part 1: terminology and phenomenology

Linguistic aspects of ‘depression’

‘Depression’ seems often to be thought of as an elemental, irreducible phenomenon such as would, for example, apply to ‘thirst’ when in fact it is a collective term more comparable to ‘pain’ in that it comprises a collection of superficially similar but actually diverse entities. So, we find inevitable diagnostic ambiguity whenever clinicians use the term ‘depression’ without qualification, as is so very frequently the case.

Further, it is often difficult to ascertain whether, in a clinical discussion around any given case, the term ‘depression’ has been used as (a) a symptom reported by the patient, (b) an informal descriptive reference to the patient’s mental state, or (c) a diagnosis. To illustrate the impact of this by way of an analogy: in a medical setting, it would be unexceptionable for a patient to present complaining of ‘pain’ and for subsequent conversations referencing the patient’s ‘pain’, but ‘pain’ (or ‘major pain’) would never be an acceptable medical diagnosis.

It is therefore incumbent on all clinicians to be specific about just what they mean when they use the term ‘depression’ or the equally uninformative ‘clinical depression’. And it is salutary and proper for them to be challenged when they aren’t.

There are unfortunate consequences of the loose use of the term ‘depression’. First, it obscures rather than illuminates clinical work. Fortunately, the English language has been endowed with a rich variety of nuanced, non-technical descriptive terms ⁷ that offer a more precise and meaningful indication of a person’s psychological experience than the stock, nondescript ‘depression’. Such descriptive terms enhance case formulation and lead to more accurate diagnosis. As an illustration, many cases of so called ‘depression’ would be more informatively described in terms of ‘demoralisation’ or ‘grief’.

Second, because the terms ‘depression’ and ‘dysthymia’ carry a formal psychiatric connotation, they may lead to undue medicalisation of patients’ life experiences such as the various forms of loss or adjustment inherent in the human condition. ⁸ With this medicalisation comes the likelihood of medical, viz. pharmacological, interventions which may be, at best, unnecessary.

On another front, we should be wary of taking patients’ reports of feeling ‘depressed’ at face value as the term is sometimes used as a euphemism for another, less engaging sentiment such as discontentment. Conversely, people may deny feeling ‘depressed’ because of a perceived connotation of characterological inadequacy.

For the reasons mentioned above, it is better to use a simple descriptive term such ‘feeling low’ instead of ‘depression’ when initially talking with, or about, a patient. This may later be revised to a more specific descriptive term – such as demoralisation, sense of loss, sadness, disappointment, regret, inner emptiness, aloneness, meaninglessness etc. – when constructing a case formulation, diagnosis and treatment plan. Compared to ‘depression’, the term ‘feeling low’ is probably also less ethnocentric and therefore more appropriate when speaking with a patient from another cultural background or generation.

The term ‘dysphoria’ is particularly apt in conversation between clinicians about patients with melancholic depression because (i) it doesn’t carry any immaterial contextual connotations and (ii) its Greek etymology correctly alludes to the ‘medical’ nature of the illness.

Finally, one needs to differentiate the lay term ‘melancholy’ which is more or less synonymous with ‘sadness’, from the clinical term ‘melancholia’ or ‘melancholic depression’ indicating a pathophysiological illness in which sadness is not usually a primary feature.

Clinical antecedents, contextual aspects and consequent experiences superimposed over the core features of a depressive condition

The total clinical complexion of a mood disorder is influenced by a number of overlapping psychosocial aspects, each of which needs to be teased out when conducting a diagnostic evaluation. The first of these aspects is the patient’s premorbid personality, comprising intrinsic temperament, affective tendencies and characterological traits. So, for example, a person with an introverted nature might be more prone to internalisation of distress and social withdrawal with the onset of a depressive syndrome, whereas someone with an extravert nature might show more conspicuously emoted distress. Personality makeup may also help explain why any given patient’s depressive condition takes on a particular quality such as dispiritedness or apprehension or regression or irritability or behavioural change.

The second aspect relates to the circumstances within which the patient currently finds himself. For instance, one person might be socially isolated and feeling lonely, and therefore inclined to seeking companionship, whereas someone in a crowded environment might be drawn to solitude.

The third – and central – component of the clinical presentation is the specific set of symptoms corresponding to the particular type of ‘depression’ from which the person is suffering. This will be discussed later under the headings of melancholic depression and the various non-melancholic forms.

The fourth, and underappreciated, aspect is the downstream impact of the depression on the person’s overall situation and resultant secondary sentiments. This could, for example, take the form of an anxious reaction to the perceived threat of personal incapacity or rejection by familiars. Another type of reaction might be sadness related to the sense of loss of their previously happy, carefree life. Yet another manifestation might be exasperation about life being so much harder when depressed. So, such feelings of apprehension or irritability or, indeed, sadness sometimes constitute secondary sentiments rather than core symptoms of ‘depression’.

It is the author’s view that sadness is not usually a core symptom of ‘depression’ but instead either (a) a marker of some form of loss, i.e. grief, which has been misrepresented through the use of the nondescript, stock term ‘depression’; or (b) a secondary sentiment as described above.

The poor correlation between distress intensity and biologicality of ‘depression’

An important but rarely mentioned issue is the relationship between intensity of psychological distress and its diagnostic implications. It would appear that some – and this includes patients and clinicians – construe high emotional distress or suicidal ideation as being symptomatic of a biological form of depression and/or requiring pharmacological intervention. Conversely, less emotive depressive presentations tend to be considered as less biological in nature. This is not necessarily so, ⁹ and experienced psychiatrists would have seen highly distressed or suicidal patients who were going through a transient social crisis ¹⁰ or, conversely, patients with a melancholic illness with comparatively unobtrusive features such as social withdrawal.

We might also consider how the clinician’s subjective position could have a bearing on how the case is evaluated. So, from a psychodynamic perspective, a patient’s emotional distress can be subliminally conveyed through the process of projective identification to the clinician who may then respond with an overly vigorous rescuing response in the tradition of the ‘medical model’ to contain his or her own countertransference anxiety (or frustration) about the patient’s condition or associated risks such as suicide.

The phenomenological relationship between ‘depression’ and ‘anxiety’

One of the enduring conundrums in psychiatry has been the highly prevalent so-called ‘co-morbidity’ between ‘depression’ and ‘anxiety’. Not only does this purported ‘co-morbidity’ confound clinicians’ thinking, it is also by way of Ockham’s Razor suggestive of a substantially flawed nosology.

There are two main reasons why feelings of apprehension and low mood are so frequently found together. The first set of reasons relates to those outlined in a preceding section on antecedents, contextual aspects and secondary sentiments. They are conceptually straightforward and don’t need reiteration.

The second, reason for the co-occurrence of ‘anxiety’ with ‘depression’ relates to the core psychopathology of melancholic depression, namely the loss of self-confidence. The phenomenology of confidence is most interesting in that it involves a duality of temporal aspects. So, in melancholia the patient’s lack of confidence is experienced as a current lowness of mood with a simultaneous, future orientated, sense of apprehensive foreboding. The latter would generally be referred to as ‘anxiety’. Hence, the feeling of ‘anxiety’ is not actually a ‘co-morbidity’ of melancholic depression but rather a key marker of the underlying loss of self-confidence. Indeed, ‘anxiety’ is often the most striking feature of a melancholic ‘depression’.

It is noted incidentally that an increase in confidence is cited in both the 4^th edition of the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) and the 10^th edition of the World Health Organization’s International Classification of Diseases (ICD-10) as a clinical feature of mania, whereas the lowering of confidence is mentioned as a symptom of depression in ICD-10 but not so in DSM-IV.

To re-state this: the loss of confidence, incorporating an integral component of anxious apprehension, is a core feature – and perhaps the most reliable clinical marker – of melancholic depression. One might therefore reasonably further contend that melancholia (and for that matter also mania, albeit of the opposite valency) actually constitutes a disorder of confidence rather than of mood. This may seem a semantic point, but it is an important one if we are to advance to a better conceptual understanding of melancholia.

And so, to round off this discussion: can evolutionary psychology shed any light onto the sociobiological underpinning of melancholia? It probably does. The notion of melancholia as a dysregulated state of ‘confidence’ with interpersonal behavioural concomitants, such as a submissive disposition, would seem to have greater explanatory power in the Darwinian sense – for example, in maintaining an orderly social pecking order, favouring species survival ¹¹ – than does the more self-enveloped phenomenon of ‘mood’ viz. experience of happiness or unhappiness.

Conclusion

The concept of ‘depression’ has been shrouded in layers of epistemological confusion stemming from (a) linguistic cross contamination between lay and professional vocabularies; (b) a simplistic, unitary notion of ‘depression’ and (c) a poor phenomenological conceptualisation of melancholia; resulting in (d) nosologically inadequate discrimination between melancholia and the various non-melancholic forms of depression; and perpetuated through (e) superficial and substantially flawed diagnostic classification systems.

The situation is remediable, however, if as a profession comprising both clinicians and academics we first acknowledge the above difficulties and then (a) promote and use nuanced, plain language descriptive terms in patient interviews and clinical case formulation; (b) reject unhelpful, nondescript or counterfeit diagnostic terms such as ‘depression’, ‘clinical depression’ ‘major depressive disorder’ and ‘dysthymic disorder’; and (c) unreservedly categorise ‘depression’ into melancholic and non-melancholic types so as to lead to conceptual clarity and coherent treatment.