Is Depression a Known Side Effect of Omeprazole, and How Common Is It?

Yes, depression is listed among the possible nervous system and psychiatric adverse reactions of omeprazole (a proton pump inhibitor). ^[1] Multiple official product labels include “psychiatric and sleep disturbances including depression” alongside agitation, anxiety, confusion, hallucinations, and insomnia. ^[2] This recognition comes from postmarketing experience and labeling rather than from a consistent signal in pre‑approval clinical trials. ^[3]

What Official Labels Say

Omeprazole’s U.S. labeling groups depression under “Nervous System/Psychiatric” adverse reactions, within a broader list of psychiatric and sleep disturbances. ^[4] The labels do not assign a precise frequency to depression; instead, they describe these effects as postmarketing observations where reliable incidence cannot be estimated. ^[5] This means depression is acknowledged as a potential effect, but how often it happens is not quantified in the official label. ^[6]

How Common Is It?

• In pre‑approval and early clinical trial summaries, omeprazole was generally well tolerated, and a distinct depression signal was not identified. ^[7] Historical pharmacovigilance summaries from early postmarketing periods focused more on confusion in older adults or those with liver disease, rather than quantifying depression specifically. ^[8] Because most psychiatric effects on the label are derived from spontaneous reports after approval, exact rates (like “common,” “uncommon,” or “rare”) are not provided for depression in official labeling. ^[5]
• Practically, this means depression appears to be uncommon and not clearly quantified in trials, with recognition based on case reports and postmarketing surveillance. ^[9]

What Research Beyond Labels Suggests

Beyond labeling, some observational studies have explored associations between proton pump inhibitor (PPI) use and mood disorders. ^[10] For example, a large Swedish cohort study in children found higher hazards of incident depression and anxiety after starting PPIs, with risk appearing greatest in the early months and persisting over time. ^[10] However, such observational findings show an association, not proof of causation, and they are not specific to omeprazole alone. ^[10]

Practical Takeaways for Users

• Depression is a recognized but not well‑quantified potential side effect of omeprazole. ^[11] If mood changes such as persistent sadness, loss of interest, or anxiety occur after starting omeprazole, consider medical review to discuss whether the medicine could be contributing and whether alternatives or dose adjustments are appropriate. ^[12]
• Because formal incidence is not established in labeling, decisions should be individualized, balancing symptom severity, timing relative to treatment, and the benefits of controlling acid‑related conditions. ^[13]

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Summary Table: What We Know About Depression with Omeprazole

Aspect	What the evidence shows
Recognition on official labels	Depression is listed among psychiatric and sleep disturbances in omeprazole labeling. [1] [2]
Frequency on labels	Not quantified; listed as postmarketing adverse reactions with unknown incidence. [5]
Clinical trials	Early summaries did not identify a consistent depression signal; omeprazole generally well tolerated. [7]
Pharmacovigilance	Postmarketing reports include psychiatric effects; early reports emphasized confusion in certain populations. [8]
Observational studies	Some cohort data (in PPIs overall) suggest an association with depression/anxiety; not proof of causation and not omeprazole‑specific. [10]

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Bottom Line

Depression is acknowledged on omeprazole’s official labeling as a potential psychiatric adverse reaction, but its true frequency is not defined and appears to be uncommon based on trial summaries and the nature of postmarketing reports. ^{[4] [7]} If depressive symptoms arise during omeprazole therapy, it is reasonable to seek medical advice about continued use and possible alternatives. ^[14]