TG and treatment resistant depression: The types of medications studied for use in augmentation therapy of TRD include mood stabilizers (e.g., lithium, lamotrigine), monoamine oxidase inhibitors, tricyclic antidepressants, thyroid hormones (e.g., T3), vitamin supplements (e.g., zinc), antipsychotics (e.g., quetiapine, olanzapine, risperidone), nicotinic antagonists, antibiotics (e.g., D-cycloserine), psychostimulants (e.g., methylphenidate), opiates (e.g., buprenorphine), and anaesthetics (e.g., ketamine).