Weed has been shown to interact poorly with antidepressant medications, such as monoamine oxidase inhibitors (MAOIs), selective serotonin reuptake inhibitors (SSRIs), tricyclic antidepressants (TAs), and serotonin-norepinephrine reuptake inhibitors (SNRIs). Adverse effects when combining antidepressants with weed can range from reduced effectiveness of the medication to mood swings, hypertension, and even hallucinations and serotonin syndrome–which can be deadly.