Citalopram: Independent Evidence on Depression, Panic, Side Effects & Withdrawal

Table of contents

• Evidence summary
• What citalopram is
• How it works
• What it is prescribed for
• What works and what does not
• Benefits by claim
• Risks and all side effects
• All interactions
• Who should avoid citalopram
• Dosage and how to take it
• Follow the money: who makes it and who funded the evidence
• Related research
• Frequently asked questions
• Sources and funding notes

Evidence summary

Independent evidence and credibility scorecard

Independence tiers: 1 = government regulator or public health body; 2 = publicly funded academic or Cochrane research; 3 = professional society, or academic work with notable author–industry ties; 4 = manufacturer-funded or manufacturer-authored. Credibility runs from A (highest) to D.

What citalopram is

Citalopram is a selective serotonin reuptake inhibitor (SSRI) antidepressant (NHS). Chemically it is a racemic mixture of R- and S-citalopram. Its S-enantiomer is sold separately as escitalopram (MHRA).

• Brand names: Cipramil in the UK (Lundbeck Ltd) and Celexa in the US (distributed by AbbVie under licence from H. Lundbeck A/S, which owns the trademark) (Cipramil SmPC, FDA label).
• Originator: H. Lundbeck A/S, headquartered in Valby, Copenhagen, Denmark. The molecule was first synthesised by Lundbeck in 1972 (University of Bristol Molecule of the Month) and launched as Cipramil in 1989 (Lundbeck history).
• US approval: 1998 (FDA label, "Initial U.S. Approval: 1998").
• Generic status: widely available as a generic. The FDA describes it as "also available in generic form" (FDA 2012), and the UK electronic Medicines Compendium lists generic citalopram from several licence holders, for example Milpharm Ltd (emc).
• Prescription status: prescription-only (POM) in the UK (SmPC, NHS). It is a prescription drug in the US and is not a controlled substance (FDA label, section 9.1).
• Forms: tablets (10, 20 and 40 mg) and oral drops. In the UK, Cipramil drops are 40 mg/ml and have about 25% higher bioavailability than tablets, so drop doses are not the same numbers as tablet doses (Cipramil Drops SmPC).

How it works

Citalopram blocks serotonin (5-HT) reuptake and has minimal effect on noradrenaline and dopamine reuptake. It has no or very low affinity for histamine, muscarinic, adrenergic, dopamine and benzodiazepine receptors (FDA label, section 12.2). This is why it tends to cause fewer anticholinergic effects (dry mouth, constipation, confusion) than older tricyclic antidepressants, which fits the lower adverse-event dropout seen against tricyclics in the Cochrane review. The NHS explains the effect as increasing serotonin, "a chemical in the brain linked to mood" (NHS). The full biological reason why antidepressants relieve depression is still not settled, and no source reviewed here claims it is.

What the body does with it

Peak blood levels occur about 4 hours after a tablet dose, and oral bioavailability is about 80%. The mean half-life is about 35 hours, so steady state is reached in about a week (FDA label, section 12.3). The liver breaks it down through CYP2C19 (about 38%), CYP3A4 (about 31%) and CYP2D6 (about 31%) (SmPC, section 4.5). This is why reduced CYP2C19 activity, liver disease and age all raise blood levels. In people aged 60 and over, exposure (AUC) was 23% and 30% higher in two studies, and the half-life was 30% and 50% longer (FDA label, section 8.5). Higher blood levels mean a larger QT effect, and that link is the basis of the dose caps.

Why the heart warning exists

The QT interval on an ECG measures how long the heart's ventricles take to reset electrically between beats. When it is prolonged, the risk of a dangerous rhythm called torsade de pointes rises, and this rhythm can be fatal. Citalopram lengthens the QT interval in proportion to dose. The FDA's analysis of a randomised, placebo-controlled crossover study in 119 adults found maximum mean increases of 8.5 ms at 20 mg and 18.5 ms at 60 mg. It estimated 12.6 ms at 40 mg from the blood-level relationship (FDA 2011). The MHRA reported a similar pattern using a different correction: 7.5 ms at 20 mg/day and 16.7 ms at 60 mg/day (MHRA).

What it is prescribed for

What works and what does not

Benefits by claim

Adult depression: real, but modest

The most independent, most complete estimate comes from the Cipriani et al. 2018 network meta-analysis in The Lancet. It pooled 522 double-blind randomised trials (116,477 participants, done between 1979 and 2016), and unpublished data were retrieved for 274 (52%) of the trials. Citalopram's response odds ratio against placebo was 1.52 (95% credible interval 1.33–1.74). That places it in the lower-middle of the pack: amitriptyline was highest at 2.13 and reboxetine lowest at 1.37. Across all 21 antidepressants, the pooled standardised mean difference on symptom scales was 0.30 (95% CrI 0.26–0.34). By convention, that is a small-to-moderate effect.

What this means in practice: an odds ratio of 1.52 describes the odds of reaching "response" (usually at least a 50% symptom reduction) and does not mean everyone improves by 52%. Many people on placebo also improve in trials. The authors note that the summary effect sizes "were mostly modest" and that the certainty of evidence was moderate to very low. They also found a "novelty effect": drugs looked better when they were the new experimental drug than when they were the older comparator (Cipriani 2018). Citalopram was usually the older comparator in later trials.

The FDA label shows how mixed the original registration trials were. Efficacy was established in two placebo-controlled studies. In the fixed-dose study, 40 mg and 60 mg worked, 10 mg and 20 mg showed "no clear effect", and 60 mg was no better than 40 mg. The label also states that in "three additional placebo-controlled trials", the difference from placebo "was not statistically significant" (FDA label, section 14). This openness is useful. Failed trials are common for antidepressants and do not by themselves show a drug is ineffective, but they explain why pooled effects are modest.

Tolerability: among the better-tolerated antidepressants

Dropouts for any reason on citalopram did not differ from placebo (OR 0.94, 0.80–1.09). In head-to-head trials, citalopram was among the more acceptable antidepressants, alongside agomelatine, escitalopram, fluoxetine, sertraline and vortioxetine (Cipriani 2018). The 2012 Cochrane review found significantly fewer dropouts due to adverse events than with tricyclics (OR 0.54, 95% CI 0.38–0.78). Fewer people reported at least one side effect with citalopram than with reboxetine or venlafaxine (Cochrane 2012). However, in the label's short-term US trials, 16% of people on citalopram stopped because of an adverse reaction, against 8% on placebo (FDA label, section 6.1).

Against other antidepressants

In the Cochrane review, citalopram was less effective than escitalopram but more effective than paroxetine and reboxetine (figures in the evidence summary). The authors warned of "the potential for overestimation of treatment effect due to sponsorship bias and publication bias" (Cochrane 2012). All 7 citalopram-versus-escitalopram trials were funded by the company that makes both drugs.

Panic disorder

In an 8-week trial of 475 people with panic disorder, citalopram 20–30 mg and 40–60 mg daily, and clomipramine, were all significantly better than placebo on the number of people free of panic attacks. All rating scales suggested that 20–30 mg worked better than 40–60 mg, and the authors concluded that 20–30 mg had the best benefit/risk ratio (Wade et al., 1997). Across antidepressants as a class, an independent Cochrane review found low-quality evidence of benefit (RR for failure to respond 0.72, 95% CI 0.66–0.79). That equals a number needed to treat of 7: seven people treated for one extra to benefit (Bighelli et al., Cochrane 2018).

Risks and all side effects

The FDA boxed warning covers suicidal thoughts and behaviours: antidepressants increased their risk in paediatric and young adult patients in short-term studies. All antidepressant-treated patients should be monitored closely for clinical worsening and for emerging suicidal thoughts and behaviours. Citalopram is not approved for paediatric patients (FDA label). In pooled trials, the drug–placebo difference per 1,000 patients was 14 additional cases under age 18, 5 additional cases at age 18–24, 1 fewer at age 25–64 and 6 fewer at 65 and over (FDA label, Table 1).

Common side effects

In the label's short-term placebo-controlled trials (1,063 on citalopram and 446 on placebo), the most frequent effects were nausea (21% vs 14%), dry mouth (20% vs 14%), somnolence (18% vs 10%), insomnia (15% vs 14%), increased sweating (11% vs 9%), diarrhoea (8% vs 5%) and tremor (8% vs 6%). Ejaculation disorder affected 6% of men, against 1% on placebo (FDA label, Table 3). The NHS lists headaches, nausea and vomiting, sweating, dry mouth, diarrhoea or constipation, sleep problems, palpitations and sexual problems. It notes that most side effects ease after a couple of weeks (NHS). The UK SmPC reports a dose-response for sweating, dry mouth, insomnia, somnolence, diarrhoea, nausea and fatigue (SmPC, section 4.8).

The QT story: what the regulators did, and the dissent

August 2011 (FDA): The FDA said citalopram "should no longer be used at doses greater than 40 mg per day". Studies "did not show a benefit" above 40 mg, and the label had previously said some patients may need 60 mg. A 20 mg/day maximum was set for people over 60, people with liver impairment, CYP2C19 poor metabolisers and people taking cimetidine (FDA 2011).

December 2011 (MHRA, after a Europe-wide review): The UK set new maximum daily doses of 40 mg for adults and 20 mg for adults over 65 and for people with liver impairment. It made citalopram contraindicated in congenital long QT syndrome or known QT prolongation, and in combination with other QT-prolonging medicines. It advised an ECG review before treatment in people with heart disease and correction of low potassium or magnesium. Yellow Card reports of QT prolongation and torsade de pointes came "mainly in women, those with hypokalaemia, or in those with pre-existing QT prolongation or other cardiac diseases" (MHRA Drug Safety Update).

March 2012 (FDA revision): The FDA changed congenital long QT syndrome from "contraindicated" to "not recommended". It recognised that some patients "could benefit from a low dose of citalopram and who lack viable alternatives", and recommended ECG and electrolyte monitoring when citalopram must be used in such patients (FDA 2012). The UK is therefore stricter on contraindications and uses age 65 for the lower cap, while the US uses 60.

Independent confirmation and dissent: An NIH-funded study of 38,397 patients' ECGs in electronic health records confirmed "a modest prolongation of QT interval with citalopram". The QTc rose by 7.8 ms going from 10 to 20 mg and by 10.3 ms going from 20 to 40 mg (Castro et al., BMJ 2013). In older people with Alzheimer's disease, 30 mg/day raised QTc by 18.1 ms (95% CI 6.1–30.1) against placebo, and no cardiovascular deaths occurred (Drye et al., 2014). A Veterans Affairs cohort went the other way. Doses above 40 mg were associated with lower ventricular arrhythmia risk (adjusted HR 0.68, 95% CI 0.61–0.76) and lower all-cause mortality (adjusted HR 0.94) than 1–20 mg, and the authors said this raises "questions regarding the continued merit of the FDA warning" (Zivin et al., 2013). Our reading: the QT effect is well established by randomised data. How often it turns into real arrhythmias at 40–60 mg is less certain, because observational data can be skewed by who gets prescribed high doses. Regulators have not reversed the caps.

All interactions

Food does not affect absorption. Always tell your prescriber and pharmacist about every medicine, herbal remedy and supplement you take (NHS).

Who should avoid citalopram

Contraindications (do not use)

• A known allergy to citalopram or any ingredient (SmPC).
• Taking an MAOI, or within the washout period; taking pimozide (FDA label).
• UK: known QT prolongation or congenital long QT syndrome, or use with other QT-prolonging medicines (SmPC). In the US these are "not recommended" rather than formally contraindicated (FDA 2012).

Use only with specialist caution

• Heart conditions: significant bradycardia, recent heart attack, uncompensated heart failure, and low potassium or magnesium (MHRA).
• Bipolar disorder or a history of mania, epilepsy, diabetes, glaucoma, bleeding disorders (especially gastrointestinal bleeding), and liver or kidney disease (NHS).
• Under 18s: not recommended (NHS). Young adults aged 18–25 need closer early monitoring, and NICE advises a review 1 week after starting (NICE NG222).

Older adults

Maximum 20 mg a day over 65 in the UK (SmPC) and over 60 in the US (FDA label). The reason is higher blood levels and a longer half-life with age (see How it works). The American Geriatrics Society's 2023 Beers Criteria lists SSRIs as drugs to avoid in people with a history of falls or fractures, unless safer alternatives are unavailable, while noting that the evidence on falls and fractures for antidepressants is mixed. It also says to use them with caution because they "may exacerbate or cause SIADH or hyponatremia", and to monitor sodium closely when starting or changing doses (AGS Beers Criteria 2023). NICE similarly advises alertness to falls, fractures and hyponatraemia in older people (NICE NG222).

Liver and kidney

Mild to moderate liver impairment: the UK SmPC recommends 10 mg daily for the first two weeks, then a maximum of 20 mg, with extra caution in severe impairment. No adjustment is needed for mild or moderate kidney impairment, and there is no information for severe impairment (creatinine clearance below 20 mL/min) (SmPC).

CYP2C19 poor metabolisers

Some people inherit slow CYP2C19 enzymes. The NIH-funded CPIC guideline gives a strong recommendation for these "poor metabolisers": consider an antidepressant that is not mainly broken down by CYP2C19. If citalopram is still appropriate, it recommends a lower starting dose, slower titration and a 50% reduction of the standard maintenance dose (Bousman et al., CPIC 2023). The US label caps poor metabolisers at 20 mg/day (FDA label).

Pregnancy and breastfeeding

Pregnancy: The NHS says citalopram can be used in pregnancy if needed, at the lowest effective dose (NHS). Published data on more than 2,500 exposed pregnancies showed no malformative toxicity. SSRI use late in pregnancy may increase persistent pulmonary hypertension of the newborn: about 5 cases per 1,000 pregnancies, against 1–2 per 1,000 in the general population. Newborns may show poor-adaptation symptoms such as breathing difficulty, jitteriness and feeding problems. Abrupt stopping during pregnancy should be avoided (SmPC 4.6). The US label notes that women who stop antidepressants in pregnancy are more likely to relapse (FDA label 8.1).

Breastfeeding: Citalopram passes into breast milk. Relative infant doses have ranged from 0.7% to 9.4% of the maternal weight-adjusted dose. There are reports of irritability, excessive sleepiness, decreased feeding and weight loss in breastfed infants (FDA label 8.2). The NHS says it can be used while breastfeeding when the benefits outweigh the risks (NHS). The UK SmPC is more cautious and says discontinuing breastfeeding "should be considered" (SmPC). This is a decision to make with your prescriber and health visitor.

Dosage and how to take it

Your prescriber sets and adjusts your dose. The table below shows only the official licensed adult ranges from the UK SmPC and the FDA label, for reference. It is not a dosing guide.

Sources: Cipramil tablets SmPC, Cipramil Drops SmPC, FDA Celexa label, MHRA.

How to take it

Take it once a day, morning or evening, with or without food. Swallow tablets whole with water. Drops are mixed into water, orange juice or apple juice. If you miss a dose, take it when you remember unless it is nearly time for the next one, and never take a double dose (NHS).

How long before it works

According to the SmPC, improvement "in general" starts after one week but may only become evident from the second week. The dose should be reviewed within 3 to 4 weeks (SmPC). The NHS says it may take "a few weeks" (NHS). For panic disorder, NICE advises changing approach if there is no improvement after a 12-week course (NICE CG113).

How long to take it

The NHS says usually at least 6 months (NHS). The SmPC says depression should be treated for at least 6 months to ensure people are free from symptoms (SmPC). For panic disorder, NICE advises continuing for at least 6 months after the optimal dose is reached before tapering (NICE CG113).

How to stop: taper under supervision

Do not stop suddenly. The NHS says the doctor will reduce the dose gradually over a few weeks (NHS). The SmPC gives a minimum of 1–2 weeks and advises tapering "over a period of several weeks or months, according to the patient's needs". If symptoms become intolerable, the prescriber may go back to the previous dose and then reduce more slowly (SmPC). NICE NG222 says the speed of withdrawal should be agreed with the person. Each reduction should wait until withdrawal symptoms have settled, and completing withdrawal "may take weeks or months" (NICE NG222).

Follow the money: who makes it and who funded the evidence

The originator: H. Lundbeck A/S (Denmark)

• Lundbeck was founded in Copenhagen in 1915 and has its headquarters in Valby, Copenhagen. It has about 5,300 employees, and its products are registered in more than 80 countries (Lundbeck at a glance).
• Ownership: the Lundbeck Foundation owns about 70% of Lundbeck's shares, and the rest trade on Nasdaq Copenhagen. The Foundation grants about DKK 500 million a year to medical research and education (Lundbeck ownership, at a glance). Any foundation-funded research on Lundbeck products is therefore not fully independent of the company's commercial interests.
• Lundbeck says the company "expanded rapidly in the 1990s, due to the success of Cipramil", which was registered in more than 70 countries. Its successor, escitalopram (Cipralex/Lexapro), was launched in 2002 and grew to account for the major share of Lundbeck's business (Lundbeck history). We did not find a primary source for citalopram's current annual revenue, so none is given here.

Current marketers and generics

• UK: Lundbeck Ltd holds the Cipramil licence (SmPC). Many generic makers also hold UK licences, such as Milpharm Ltd (part of Aurobindo) (emc).
• US: The Celexa label is published under Allergan, Inc. and states "Distributed by: AbbVie Inc." and "Licensed from H. Lundbeck A/S" (FDA label). Before this, Celexa was promoted in the US by Forest Pharmaceuticals, a subsidiary of New York-based Forest Laboratories (DOJ 2010).

Who funded the evidence

• Registration and head-to-head trials (industry): The Cochrane reviewers found that "most of the included studies were funded by industry and only one study was clearly not funded by industry sponsor". Nine of 11 trials against tricyclics and 11 of 16 against other SSRIs were sponsored by, or had an author linked to, the citalopram manufacturer. All 7 trials against escitalopram were sponsored by the company that makes both drugs (Cochrane 2012).
• Independent syntheses (public money): The Cipriani 2018 network meta-analysis was funded by the UK NIHR and the Japan Society for the Promotion of Science, and the funder had no role. In that dataset, "funding by industry was not associated with substantial differences in terms of response or dropout rates". The authors add that "non-industry funded trials were few" (Cipriani 2018).
• Heart-safety evidence (mixed, mostly public): The QT signal came from a thorough QT study reviewed by the FDA, and was confirmed by NIH-funded work (Castro 2013, CitAD). Several CitAD and Castro investigators declared personal ties to companies including Forest and Lundbeck. The funding was public, but some individuals were not free of conflicts.

Documented integrity events

• 2010 US criminal plea and civil settlement: Forest Pharmaceuticals agreed to plead guilty to charges including "the illegal promotion of Celexa for use in treating children and adolescents suffering from depression". Forest agreed to pay more than $313 million in total, including a $150 million criminal fine and $14 million in forfeited assets, for matters involving Levothroid, Celexa and Lexapro. The government alleged that Forest circulated the positive results of its own adolescent Celexa study while failing to discuss a contemporaneous negative European adolescent study. The civil complaint also alleged kickbacks to prescribers. These civil allegations were settled rather than proved at trial (US Department of Justice, 15 September 2010).
• Ghostwriting of a paediatric trial: An analysis of about 750 litigation documents concluded that manuscript drafts of the paediatric CIT-MD-18 trial "were prepared by company employees and outside ghostwriters", and that "protocol-specified outcome measures showed no statistically significant difference between citalopram and placebo" (Jureidini, Amsterdam & McHenry, 2016). Citalopram remains unapproved for under-18s (FDA label).

Bottom line on money: Most of the raw trial data on citalopram came from the companies that sold it, and documented misconduct around its use in children is part of the record. However, the adult efficacy and tolerability conclusions in this article rest mainly on publicly funded syntheses that included unpublished data, and the safety limits come from regulators and publicly funded studies. That combination is why we grade adult-depression efficacy as strong but modest, and treat the QT and paediatric concerns as real.

Related research

• Stress, anxiety and depression: evidence-based prevention guide
• Supplements for stress, anxiety and depression: independent evidence
• St John's wort: evidence and interactions (do not combine with citalopram)
• Saffron for depression: evidence review
• Ashwagandha: evidence and safety
• L-theanine · Magnesium
• Sleep prevention guide · Sleep supplements evidence · Melatonin
• Sibling medicine reviews: Escitalopram · Sertraline · Fluoxetine · Paroxetine · Mirtazapine · Venlafaxine · Duloxetine

Frequently asked questions

Sources and funding notes

• NHS: Citalopram, an antidepressant medicine (reviewed 26 June 2026) — UK government public-health information; no commercial funder.
• FDA-approved Celexa (citalopram) prescribing information, DailyMed (SPL version published August 2026) — manufacturer-drafted (AbbVie, under licence from Lundbeck, Denmark), FDA-approved.
• FDA Drug Safety Communication, 24 August 2011: Abnormal heart rhythms associated with high doses of Celexa (archived copy) — US regulator; tier 1.
• FDA Drug Safety Communication, 28 March 2012: Revised recommendations for Celexa (archived copy) — US regulator; tier 1.
• MHRA Drug Safety Update, Vol 5 Issue 5, December 2011: Citalopram and escitalopram, QT interval prolongation — UK regulator, following a Europe-wide review; tier 1.
• Cipramil 20 mg film-coated tablets SmPC (revised 11/2023) — Lundbeck Ltd (UK); regulator-approved.
• Cipramil Drops 40 mg/ml SmPC — Lundbeck Ltd; regulator-approved.
• Citalopram 10 mg tablets SmPC (Milpharm Ltd) — generic licence holder; used for generic availability only.
• NICE NG222: Depression in adults, treatment and management (2022) — UK public body; committee members declare interests.
• NICE CG113: Generalised anxiety disorder and panic disorder in adults (amended 2020) — UK public body.
• Cipriani et al., Lancet 2018: Comparative efficacy and acceptability of 21 antidepressant drugs — NIHR (UK) and JSPS (Japan) funded; funder had no role; some author industry fees.
• Cipriani et al., Cochrane Database Syst Rev 2012: Citalopram versus other anti-depressive agents for depression — University of Verona (Italy), internal support; underlying trials mostly industry-funded.
• Bighelli et al., Cochrane 2018: Antidepressants versus placebo for panic disorder in adults — Cochrane group whose largest funder is the UK NIHR; one author declared industry lecture fees.
• Wade et al., Br J Psychiatry 1997: The effect of citalopram in panic disorder — UK-led multinational RCT; sponsor not stated in the PubMed record we accessed.
• Castro et al., BMJ 2013: QT interval and antidepressant use — funded by US NIH/NLM and NIMH; one author declared extensive industry ties, including Lundbeck and Forest.
• Drye et al., PLoS One 2014: Changes in QTc interval in the CitAD trial — funded by US NIA and NIMH (R01AG031348); several investigators declared industry ties.
• Zivin et al., Am J Psychiatry 2013: Evaluation of the FDA warning against prescribing citalopram at doses exceeding 40 mg — US Veterans Affairs data and VA-affiliated authors; we could not verify the funding statement.
• Bousman et al., CPIC guideline 2023: CYP2D6, CYP2C19 and serotonin reuptake inhibitor antidepressants — funded by the US NIH; two authors hold equity in pharmacogenetic companies.
• American Geriatrics Society 2023 updated Beers Criteria — US professional society; panel conflicts disclosed and conflicted members recused.
• Jureidini, Amsterdam & McHenry, Int J Risk Saf Med 2016: The citalopram CIT-MD-18 paediatric depression trial — academic analysis of litigation documents (Australia/USA); we could not access the authors' full conflict statement.
• US Department of Justice press release, 15 September 2010: Forest pleads guilty; to pay more than $313 million (archived copy) — US government legal record.
• Lundbeck: Our history, At a glance and Organization and ownership — manufacturer (Denmark); corporate facts only.
• University of Bristol School of Chemistry, Molecule of the Month: Citalopram (2009) — academic educational page (UK); used only for the 1972 synthesis date.

Last reviewed: 26 September 2026. Educational information from Pure City Research, not medical advice. Medicine decisions belong with a qualified prescriber.