Why don’t we talk about negative psychotic symptoms in affective bipolar disorder?

The classifications of the psychiatric disorders that we manage¹ contemplate the possibility of positive psychotic symptoms being present in bipolar disorder. They describe how these symptoms can appear in both the depressive and the manic and the mixed phases, how they can be congruent or incongruent with patient mood and, lastly, how they can adopt the form of delirium and/or hallucinations. These classifications also add that these symptoms cannot persist more than 2 weeks once the affective episode has been resolved, because we would have to change the diagnosis if they did last longer.

We often notice that symptomatic recovery is not accompanied by functional recovery in the bipolar patient.² Among other factors, this deficiency is attributed to the proven cognitive deterioration³ and to what are called interepisode subsyndromal depressive symptoms⁴ that these patients suffer. In this sense, it would be interesting to try to discriminate (which is sometimes quite complicated) whether these subsyndromal depressive symptoms are really negative psychotic symptoms in some cases. Perhaps we should consider a differential diagnosis of these symptoms that is the «inverse» of what we do with the schizophrenic patient and their negative symptoms.⁵ We feel that, in schizophrenic patients, it is useful to carry out a differential diagnosis of the negative psychotic symptoms with possible depressive symptoms and we also consider this fact to be important in treatment. Bipolar patients sometimes show a type of symptoms that, in a schizophrenic patient, would be called negative psychotic symptoms.⁶ In fact, the clinical presentation is identical and we do not know the aetiopathogenesis.

Our reticence to speak about negative psychotic symptoms in bipolar disorder could be related to our fear of creating even more confusion than what already exists. If these symptoms are found even when the patient is euthymic and the symptoms persist over time, it is possible that the concept of psychosis in bipolar affective disorder needs to be updated.⁷ However, it is important to bear this question in mind when setting up therapeutic planning. Faced with the presence of these symptoms, and having eliminated depressive symptomatology, perhaps we should insist on the use of certain pharmacological measures (such as what are called atypical antipsychotics^8,9) and on neurorehabilitation measures as well.¹⁰

All of the above once again confronts us with the problem of our lack of knowledge about the aetiopathogenesis of psychiatric syndromes and their symptoms. Perhaps the forthcoming incorporation of dimensions to the current diagnostic categories, in this case the dimension of «negative symptoms» to the bipolar category, will help to advance in this sense.¹¹

Funding

Funded by research aid PS09/01760 of the Health Research and FEDER funds.