Last reviewed 2026-04-22 · How we verify

citalopram (SSRI)

Citalopram selectively inhibits the reuptake of serotonin at the neuronal synapse, increasing serotonin availability in the brain.

Citalopram selectively inhibits the reuptake of serotonin at the neuronal synapse, increasing serotonin availability in the brain. Used for Major depressive disorder, Panic disorder, Obsessive-compulsive disorder (off-label).

At a glance

Mechanism of action

Citalopram blocks the serotonin transporter (SERT), preventing the reabsorption of serotonin from the synaptic cleft back into presynaptic neurons. This increases serotonin concentration in the synapse, enhancing neurotransmission and improving mood regulation. It has minimal effects on other neurotransmitter systems compared to older antidepressants.

Approved indications

• Major depressive disorder
• Panic disorder
• Obsessive-compulsive disorder (off-label)

Common side effects

• Nausea
• Headache
• Insomnia
• Somnolence
• Sexual dysfunction
• Dry mouth
• Diarrhea
• Tremor

Key clinical trials

• TDM-Guided Treatment With SSRIs in Hospitalized Adults and Children (PHASE4)
• Citalopram as a Posterior Cortical Protective Therapy in Parkinson Disease (PHASE2)
• Pattern Separation in Major Depressive Disorder (PHASE1)
• Treatment of Psoriasis With Depression and/or Anxiety With Methotrexate vs Combined Methotrexate and Antidepressant (PHASE4)
• A Study Following Women in Menopause Treated With a Non-hormonal Therapy for Hot Flashes and Night Sweats
• Citalopram and the Risk of Serious Adverse Events
• Escitalopram and the Risk of Serious Adverse Events
• Escitalopram in Asthma Patients With Frequent Exacerbation (PHASE2)

Primary sources

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