Effects of a Single Dose of Amisulpride on Functional Brain Changes

Effects of a Single Dose of Amisulpride on Functional Brain Changes During Reward- and Motivation-related Processing

This study is designed to investigate effects of a single dose of amisulpride on functional brain changes during reward- and motivation-related processing and at rest in healthy volunteers (HV) and in patients with Major Depressive Disorder (MDD).

Double blind, placebo-controlled, randomized, single dose, parallel-group design The study is designed to investigate effects of a single dose of amisulpride on functional brain changes during reward- and motivation-related processing and at rest. Measurement of functional brain changes will occur after a single dose of amisulpride or placebo in HV and patients with MDD. It is hypothesized that functional brain changes previously linked to reward- and motivation-related processing require dopaminergic signaling and are diminished in MDD compared to HV. In MDD, but not in HV, treatment with a single low dose (100 mg) amisulpride should increase brain activation associated with reward- and motivation-related processing. To test these hypotheses, we will implement a randomized, placebo-controlled, parallel- group design with 4 treatment arms (MDD/placebo, MDD/amisulpride, HV/placebo and HV/ amisulpride). All subjects will undergo MRI scanning sessions at Visit 3 and Visit 4. Treatment with amisulpride or matching placebo will occur 3.5 to 4 hours before the start of each scanning session. Time of treatment will be standardized across subjects.

At Visit 3 and Visit 4, blood samples will be taken 30 minutes pre-dose, and 1 hour, 3.5 to 4 hours, and 4.5 to 5 hours after oral drug administration to determine target plasma levels of amisulpride.

The study is composed of 4 outpatient visits: Screening, baseline and 2 scanning sessions.

MDD Patients:

Inclusion:

• Male and female patients with MDD; aged 18 to 45 years
• Montgomery-Åsberg Depression Rating Scale (MADRS) score > 7 and <26 at screening.

Exclusion:

• Meeting diagnostic criteria for any major psychiatric disorder (other than MDD), as determined by DSM-5 at screening.
• Having received prescribed medication (including antidepressants (AD)) within 14 days or fluoxetine within 90 days prior to Visit 3 (apart from the contraceptive pill).
• Having received psychotherapy within 14 days prior to Visit 3.
• Positive severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) test.

Healthy Volunteers:

Inclusion:

• Healthy
• aged 18 to 45 years

Exclusion:

• Meeting diagnostic criteria for any major psychiatric disorder.
• A history of psychiatric or neurologic disorders.
• Having received prescribed medication within 14 days prior to Visit 3 (apart from the contraceptive pill).
• Positive SARS-CoV-2 test.