The effect of SSRIs on threat of shock potentiated neural circuitry

Summary

This is an experimental research study designed to examine the effects of antidepressants on emotional processing and underlying neural circuitry.

This study will use a between-subject double-blind design: participants will be randomly allocated to take 14-21 days of daily escitalopram(10mg) or placebo. The first session will be a screening session lasting around 1.5 hours where participants will be asked to complete standardised structured interviews and complete some self-report questionnaires to determine their cognitive and emotional traits.

We are recruiting two groups of participants: individuals with high anxiety symptoms, and control individuals with no personal or family history of mood and anxiety disorders.

We are requesting access to the GLAD study solely to recruit the former group. If participants meet the inclusion/exclusion criteria of this study and are willing to take part, they will complete two sessions of computerised cognitive tasks in a magnetic resonance imaging scanner(before and after the course of medication).This allows the impact of the intervention on the neural circuitry involved in processing emotional stimuli to be examined.

These sessions will last approximately 2.5hours. Some tasks will have periods of ‘threat of shock’ which serve to induce temporary stress, and matched safe periods.

Shock levels will be individually calibrated to find appropriate levels of shock for each participant. The shocks are rare and harmless, and comparable to a rubber band being snapped against the wrist/ankle–this procedure has been used in multiple previous projects with no consequent adverse events.

Between the two testing sessions, participants will be given either escitalopram or placebo tablets to take home. They will be given an information pack and clinical cover for the duration of the study.