Prefrontal cortex stimulation prevents stress-induced HPA axis reactivity in people at familial risk of schizophrenia

Schizophrenia is a multifactorial disorder with a range of risk factors. Dysregulation in the systems involved in the stress response is a key component of its pathophysiology. Individuals at risk of developing schizophrenia exhibit hyperreactivity to stress and altered cognitive performance, both known as vulnerability markers. This study aims to determine whether stimulation of the prefrontal cortex can reduce reactivity to stress in unaffected siblings of patients with schizophrenia.

In a randomized, sham-controlled trial, 27 participants were assigned to receive either active (n = 14) or sham (n = 13) transcranial direct current stimulation (tDCS) over the prefrontal cortex for 30 min during exposure to an acute stressor. The stress response was measured biologically, via salivary cortisol levels, and cognitively, through a reality monitoring task, which serves as an intermediate cognitive vulnerability marker.

In contrast to the sham condition, active stimulation significantly reduced cortisol release in response to stress (F_(9,216) = 1.972; p = 0.04) and prevented stress-induced impairment in reality monitoring (F_(1,23) = 9.954; p = 0.004).

These findings suggest that tDCS should be a promising tool for reducing stress-induced biological and cognitive reactivity in a population at risk of schizophrenia.