Depressed Mood Improvement Through Nicotine Dosing 3

Eligibility Criteria

• 1. Age ≥ 60 years;
• 2. diagnosis of major depressive disorder, single or recurrent episode (DSM5);
• 3. On a stable therapeutic dose of an allowed SSRI or SNRI for at least 6 weeks;
• 4. severity: at least mild active depression symptoms, defined as MADRS ≥ 15;
• 5. cognition: MMSE ≥ 24;
• 6. fluent in English
• 1. Other Axis I psychiatric disorders, except for generalized anxiety disorder (GAD) or social phobia symptoms occurring in a depressive episode or diagnosis of an attentional disorder, such as Attention Deficit Hyperactivity Disorder (ADHD);
• 2. Use of other augmentation medication treatments for depression or ADHD e.g., stimulant medications (e.g., adjunctive bupropion or other augmenting agents) that the participant does not want to stop, although short-acting sedatives are allowed;
• 3. Any use of tobacco or nicotine in the last year.
• 4. Living with a smoker or regular exposure to secondhand smoke.
• 5. History of alcohol use disorder or substance use disorder of moderate or greater severity (endorsing 4 or more of the 12 criteria) in the last 12 months.
• 6. Acute suicidality.
• 7. Acute grief (\<1 month);
• 8. Current or past psychosis.
• 9. Primary central nervous system neurological disorder, including dementia, stroke, epilepsy, etc.;
• 10. Presence of unstable medical illness requiring urgent treatment or intervention;
• 11. MRI contraindication.
• 12. Electroconvulsive therapy or transcranial magnetic stimulation in last 2 months;
• 13. Current or planned psychotherapy where the potential participant does not want to pause therapy for the duration of the study;
• 14. Allergy or hypersensitivity to nicotine patches;
• 15. In the last 4 weeks, regular use of drugs with central cholinergic or anticholinergic properties or moderate / severe CYP2A6 inhibitors /inducers