MEDICATION GUIDES · GUIDE 01
SSRIs
Selective serotonin reuptake inhibitors include sertraline, escitalopram, fluoxetine, paroxetine, and citalopram.
These guides describe patterns across a drug class, not a prediction for one person. Benefits, side effects, interactions, and tapering needs vary by medication, dose, health history, and other treatments. Never start, stop, or change a psychiatric medication without the prescribing clinician.
EVIDENCE REVIEW
SEPTEMBER 24, 2026
How they work—and what that does not prove
SSRIs block the serotonin transporter, so serotonin remains available between brain cells longer. That happens quickly; the clinical effect takes longer as receptors and brain networks adapt.
Important distinction: raising serotonin does not establish that depression is caused by “low serotonin.” A 2022 umbrella review found no consistent evidence for that simple theory; critics argue that the theory was already outdated and that serotonin dysregulation may matter for some subgroups. The patient-safe conclusion is narrower: these medicines help many people, while depression remains biologically and socially complex.
SOURCE · STATPEARLS SOURCE · MONCRIEFF REVIEW SUMMARY SOURCE · PUBLISHED RESPONSE
What they are used for
SSRIs are used across depressive and anxiety disorders, including major depression, generalized anxiety, OCD, panic disorder, PTSD, and social anxiety disorder. Particular medications also have labeled uses such as bulimia nervosa or premenstrual dysphoric disorder. A diagnosis alone does not determine which drug is appropriate.
What to expect
- Early: nausea, sleep change, headache, dry mouth, sweating, dizziness, bowel changes, or temporary jitteriness. Many early effects ease over the first few weeks.
- Important to discuss: sexual dysfunction may persist rather than fade. Surveys and studies report a wide range, reflecting differences in methods and medication.
- Often missed: emotional blunting—less access to joy or sadness—has been reported by roughly 40–60% in surveys, but definitions and estimates vary widely.
SOURCE · MAYO CLINIC SOURCE · SEXUAL DYSFUNCTION REVIEW SOURCE · EMOTIONAL BLUNTING REVIEW
Timeline and stopping
Some improvement can appear during weeks 1–4, often first in sleep, appetite, energy, or dread. A fuller response commonly takes 6–8 weeks or longer at a therapeutic dose. Progress is usually gradual and uneven—not a sudden switch.
Abrupt stopping can produce discontinuation symptoms within days: flu-like feelings, insomnia or vivid dreams, nausea, imbalance, sensory disturbances such as “brain zaps,” and hyperarousal. This is not the same as addiction. Paroxetine is generally harder to stop because of its short half-life; fluoxetine’s long half-life usually makes withdrawal less abrupt. Tapering should be individualized with a clinician and may take weeks to months.
SOURCE · ONSET META-ANALYSIS SOURCE · DISCONTINUATION REVIEW SOURCE · HARVARD HEALTH
How individual SSRIs differ
“Activating” and “sedating” are clinical shorthand; either insomnia or sleepiness can occur with any SSRI, and individual response varies.
SOURCE · PSYCHIATRYRX COMPARISON SOURCE · CANADIAN ANTIDEPRESSANT TABLE
