Neural Basis of Delusions in Schizophrenia: Translational Implications for Therapeutic Neuromodulation

Abstract

Delusions are false, fixed beliefs which are held with incredible
conviction, in spite of being substantiated to the contrary. These are
present in a number of brain disorders, primarily representing one of the
fundamental components of schizophrenia, presenting in about 70% of
the patient population. Responsivity of delusions to antipsychotic medication,
if present, is only partial, with absolutely no response in several
other cases. Limited studies have engaged in exploring the neural substrates
of delusion. The most extensive study conducted in this field has
implicated the right dorsolateral prefrontal cortex (rDLPFC) disruption,
to be clinically associated with the severity of delusions. Using a brain
stimulation technique, high-definition transcranial direct current stimulation
(HD-tDCS), targeting the rDLPFC, has a potential to induce neuroplasticity
changes that are presumed to decrease the delusion score
and severity. Using HD-tDCS, focalized neuromodulation of rDLPFC can
be implemented. Alongside mainstream treatment such as antipsychotic
medications and cognitive behavioral interventions, HD-tDCS to rDLPFC,
holds the potential to be an effective treatment module for addressing
refractory delusions in schizophrenia.