Title: Brain networks reveal the effects of antipsychotic drugs on schizophrenia patients and controls,
Abstract: The study of brain networks, including derived from functional neuroimaging
data, attracts broad interest and represents a rapidly growing
interdisciplinary field. Comparing networks of healthy volunteers with those of
patients can potentially offer new, quantitative diagnostic methods, and a
framework for better understanding brain and mind disorders. We explore resting
state fMRI data through network measures, and demonstrate that not only is
there a distinctive network architecture in the healthy brain that is disrupted
in schizophrenia, but also that both networks respond to medication. We
construct networks representing 15 healthy individuals and 12 schizophrenia
patients (males and females), all of whom are administered three drug
treatments: (i) a placebo; and two antipsychotic medications (ii) aripiprazole
and; (iii) sulpiride. We first reproduce the established finding that brain
networks of schizophrenia patients exhibit increased efficiency and reduced
clustering compared to controls. Our data then reveals that the antipsychotic
medications mitigate this effect, shifting the metrics towards those observed
in healthy volunteers, with a marked difference in efficacy between the two
drugs. Additionally, we find that aripiprazole considerably alters the network
statistics of healthy controls. Using a test of cognitive ability, we establish
that aripiprazole also adversely affects their performance. This provides
evidence that changes to macroscopic brain network architecture result in
measurable behavioural differences. This is the first time different
medications have been assessed in this way. Our results lay the groundwork for
an objective methodology with which to calculate and compare the efficacy of
different treatments of mind and brain disorders.