Antidepressant discontinuation syndrome is a condition that can occur following the interruption, dose reduction, or discontinuation of antidepressant drugs, including selective serotonin re-uptake inhibitors (SSRIs) or serotonin–norepinephrine reuptake inhibitors (SNRIs). The symptoms can include flu-like symptoms and disturbances in sleep, senses, movement, mood, and thinking. In some cases, symptoms may be mild, short-lived, and resolve without treatment. More severe cases may only be successfully treated by reintroduction of the drug, provided reintroduction is done in a timely fashion. Symptoms, including tardive akathisia, and Post SSRI Sexual Dysfunction (PSSD) may persist for months to years.