Diversity in depression was the subject for Koen Demyttenaere (University Hospital Gasthuisberg, Leuven, Belgium). And he started with the astonishing number of ways in which DSM-5 allows depressed patients to be different.

Given that someone can be classed as having major depressive disorder (MDD) based on any five symptoms from a list of nine, there are potentially 227 unique profiles. And two patients, both diagnosed as having depression, can – at least in theory – have only one symptom in common.

Two patients diagnosed as having depression might have only one symptom in common

A striking feature of patients included in the STAR*D study is that 21% had anhedonia but not depressed mood – a phenomenon which is sometimes covered by the paradoxical term of “depression without depression”.

This led Professor Demyttenaere into the second of his themes – the fact that the absence of positive affect plays little part in assessment of outcome. Is it that psychiatrists are too little interested in pleasure? he asked.

Is anhedonia the most specific symptom in depression?

Neither HAM-D nor MADRS assess positive affect; and they assess hedonic function only poorly.

To combat that bias, he favors use of the Center for Epidemiological Studies – Depression (CES-D) scale, since six of the twenty items deal with negative mood and a further four with lack of positive mood.

Anhedonia is arguably the most specific feature of depression, he suggests.

Koen Demyttenaere and colleagues have also developed the Leuven Affect and Pleasure Scale (LAPS) to take better account of positive affect and anhedonia and more adequately reflect the patient’s perspective.

Diversity in symptoms, expectations and beliefs

We are faced with diversity among patients in their depressive symptoms, and with a bewildering diversity of scales used to assess response to treatment. We also have diversity of expectations – between patients themselves, and between patients and clinicians. And this is important since it affects outcome.

The top priorities for patients are having a meaningful life, enjoying life, and being satisfied with themselves. For physicians they are a reduction in negative feelings, a reduction in depressed feelings and anhedonia, and social life and leisure.

The greater the divergence between patient and physician at baseline, the poorer the treatment outcome at six months.

Tailoring treatment

Patients are more likely to perceive a reduction in depressive symptoms with pharmacological treatment if they believe their condition is less influenced by social factors, if they believe their doctor has understood their problem, and if the consultation has lasted longer.

Differences in beliefs about the causes of depression and the doctor-patient relationship affect outcome

Outcome is also influenced by demographic diversity. It is often said that the 47% response to first-line treatment in STAR*D is disappointing, but in certain groups the rate was substantially better. Of patients with 14 years or more of education, no history of trauma or distress, and who were female, 63% responded.

Symptomatic remission not sufficient

These themes were taken up by Malcolm Hopwood (University of Melbourne, Australia) who argued that restoring function is the cornerstone of remission but also questioned whether the physician’s concept of remission aligned with that of patients.

Changes in negative affect at week one predict remission at week six -- but with only half the effect size of changes in positive mood. If we asked about positive affect in a more thoughtful and interested way, we might be able to tailor treatment more effectively to the individual patient and the presence or absence of early response, he suggested.

We have a role in helping patient’s achieve a meaningful life, whatever the therapy

Professor Hopwood and colleagues have developed the CHEER index -- a tool for primary care physicians to use in identifying emotional blunting in patients with depression. At the very least, it acts as a stimulus to start a conversation about what patients most value as the outcome of treatment.

Our judgment is that symptomatic remission is not sufficient. Patients value most the functional benefits, particularly factors such as being able to return to work.

In panel discussion about the role of psychotherapy, Professor Hopwood was asked about patients’ pursuit of a meaningful life. We have a role in helping patients achieve that, whatever the therapeutic route, he suggested. And Stephen Stahl (University of California San Diego, USA), who chaired the session, added that not having depression might be necessary for having a meaningful life, but was not in itself sufficient.