Dados do Trabalho

Título

Psychic Map of the Effect of Ketamine Treatment in a Schizophrenic Patient: A Perspective from Computational Psychiatry

Introdução

Confirmation of the rapid and robust antidepressant and anti-suicidal effect of ketamine positions it as a strong psychopharmacological alternative in mood disorders; studies have also explored its effect for negative symptoms of schizophrenia, and it may come to be a psychiatric arsenal in these symptoms.
In addition, the advancement of language computational analysis techniques opens a new field in Psychiatry, conferring objectivity and comparability to medical evaluation. Speech Graphs (SG) are potential biomarkers for formal thought disorders, allowing phenomenological aspects to be graphic-mathematic mapped linked to the form of thought (it allows loosening of associations quantification).

Objetivo

To evaluate ketamine-induced psychic effects in a super-refractory schizophrenic (SRS) patient by computational technique.

Método

In an intervention study, an SRS patient received subcutaneous ketamine infusion in a subanesthetic dose to reduce negative symptoms and suicidality. Speech reports were collected, and SG attributes were calculated in two periods: pre-infusion (T0) and during the peak effect of the substance (T1). Healthy volunteer without ketamine reports was collected. The graphs were randomized 1000 times, generating a normal distribution bell’s curve; the standard deviation (SD) was calculated.

Resultados

We found an increase in verbosity, lexical variety, and long-recurrent measures, in addition to a reduction of short recurrence measures inpatient after infusion, compared with baseline (T1 vs T0). In contrast to a healthy volunteer, the measurements at T1 are close to the attributes calculated for the healthy control (T1 vs. control), but they are distanced when a comparison of T0 vs. control is established. It is worth highlighting an increase in the SD of the patient's original speech at T1 in relation to T0 for the mean of random speech, with values close to the original graph of the control.

Conclusão

Long-recurrent connectivity measures are anticorrelated with negative symptoms of chronic psychosis, typifying a disconnected speech and, by extension, formal disorganization of thought. Our findings observed an increase in the long recurrence values and reduction in the short recurrence attributes after infusion, possibly reflecting negative symptoms improvement measured by this technique. The result corroborated by the approximation of the SG attributes in T1 vs control. The SD in T0 is closer to random speech in the bell’s curve and distances itself in T1 and control.

Palavras-chave

Schizophrenia; Ketamine; Speech Graph.