Is it normal to feel tired and down while taking sertraline (selective serotonin reuptake inhibitor)?

Is It Normal to Feel Tired and Down While Taking Sertraline?

Yes, fatigue and feeling down are recognized side effects of sertraline, particularly during the initial weeks of treatment, but persistent or worsening symptoms warrant immediate clinical reassessment to distinguish between normal adjustment, inadequate treatment response, or emerging adverse effects. 1, 2, 3

Common Side Effects During Sertraline Treatment

• Fatigue is explicitly listed as a common adverse effect in the FDA prescribing information for sertraline, along with feeling tired or fatigued 3
• The American Family Physician guidelines confirm that fatigue, along with dizziness, headache, and other symptoms, are commonly reported with SSRIs including sertraline 2
• These side effects are typically "mild and short-lived" according to clinical guidelines, though they cause 10-20% of patients to discontinue treatment 2

Critical Distinction: Side Effect vs. Treatment Failure

• If you're experiencing persistent low mood ("feeling down") while on sertraline, this may indicate inadequate treatment response rather than a side effect 1
• The American Academy of Child and Adolescent Psychiatry notes that initial adverse effects of SSRIs can include anxiety or agitation, which may be confused with worsening depression 1
• Behavioral activation symptoms—including motor restlessness, insomnia, impulsiveness, and agitation—can occur, especially early in treatment 4

When to Be Concerned: Red Flags

• Feeling anxious or having trouble sleeping are specifically listed as serious side effects requiring medical attention 3
• If fatigue is accompanied by mental status changes, confusion, or loss of consciousness, seek immediate medical help as these may indicate serotonin syndrome 3
• Worsening depression or emergence of suicidal thoughts requires urgent evaluation, as SSRIs carry a boxed warning for increased suicidal thinking in patients under 24 years 4

Timeline and Management Expectations

• Most side effects, including fatigue, are transient and decrease with continued treatment 5, 6
• The American Academy of Child and Adolescent Psychiatry recommends dose adjustments at 1-2 week intervals for shorter half-life SSRIs like sertraline when optimizing treatment 1
• If symptoms persist beyond 2-4 weeks or worsen, contact your prescriber to assess whether dose adjustment, medication change, or additional evaluation is needed 1

Practical Considerations

• Do not abruptly discontinue sertraline, as this can cause withdrawal symptoms including dizziness, fatigue, irritability, and confusion 3
• Sertraline can cause sleepiness or affect your ability to make decisions and react quickly, so avoid driving or operating heavy machinery until you know how it affects you 3
• Document the pattern of your symptoms: Are they constant or intermittent? Worse at certain times of day? This information helps your provider determine if this represents normal adjustment, inadequate dosing, or an adverse reaction 1