Eligibility requirements

• Age: 18-70
• Sex:
• BMI: 17.5-38
• Medication: Inclusion Criteria: – Taking a stable dose of a first-line or second-line antidepressant approved for the treatment of depression (excluding TCAs, MAOIs & vortioxetine) Exclusion Criteria: – Type I or Type II diabetes requiring insulin – Treatment with stimulant drugs for ADHD – Regular use of benzodiazepines or similar sedative drugs in the daytime. Nocturnal use, if stable and provided the use is at least 12 hours prior to a trial visit, is allowed – Chronic opioid therapy using a Schedule 8 drug – Sedative antihistamines (taken in the daytime) – Current use of cannabis/marijuana, or THC-containing medications
• Medical History: Inclusion Criteria: – Positive MDD primary diagnosis (confirmed at screening visit) with self-reported subjective cognitive dysfuntion Exclusion Criteria: – Active suicidal ideation – History of clinically diagnosed dementia – History of severe depression treated with electroconvulsive therapy – Treatment with transcranial magnetic stimulation within 3 months prior to enrolment – History of liver disease requiring medical intervention or persisitent liver function test elevations (unless due to Gilbert’s Syndrome) – History of significant hypoglycaemia in the past 5 years – History of disease related to the hypothalamus, the pituitary and/or the adrenal glands – History of medically diagnosed peripheral neuropathy – Active malignancy (excluding local BCC or SCC) – Known allergy to trial drug or any excipients of the formulation (including lactose, talc, magnesium stearate, croscarmellose sodium)
• Smoking History: Eligible if: – ≤5 cigarettes a day or equivalent nicotine/tobacco products (including vaping) – Willing to abstain from nicotine/tobacco products on cognitive testing days