A postoperative complication was linked to new mental health disorders within a year

Design

Population-based retrospective cohort (Ontario health administrative data)

Population

1,165,711 adults undergoing one of 25 common operations, 2007–2019

Primary outcome

New or worsening mental health disorder within 1 year

Effect

6.2% vs 4.9%; aOR 1.28 (95% CI 1.24–1.32) at 1 year; aOR 1.77 (1.65–1.90) at 30 days

This Ontario population study linked health records for 1,165,711 adults who had one of 25 common operations between 2007 and 2019, and asked whether a complication within 30 days was followed by new or worsening mental health disorders over the next year.

Overall, 5.0% had a new or worsening disorder. The rate was 6.2% after a complication and 4.9% without one; after adjustment for patient, surgeon and procedure factors, the odds were 28% higher at one year and 77% higher at 30 days. The association appeared in patients with no prior psychiatric history and not in those who already had one. New psychiatrist consultations doubled after a complication (3.2% vs 1.5%), and new psychotropic prescriptions were more common.

This is observational and cannot show that the complication caused the disorder; sicker patients have more complications and more distress. But the absolute gap is consistent and the timing fits. The practical change is small and cheap: at follow-up after a complicated course, ask about mood, sleep and anxiety, and know where to refer. That matters as much in Indian surgical wards, where psychiatric follow-up is rarely built into surgical pathways. It was published on 28 September 2026.

• After a complicated postoperative course, ask about mood, sleep and anxiety at the follow-up visit.
• Pay particular attention to patients with no previous psychiatric history; this is where the association appeared.
• The highest-risk window was the first month after surgery.
• Know your local referral pathway for liaison psychiatry or counselling before you need it.
• Include a line on emotional recovery in discharge information after a complication.

Why it matters

Surgical follow-up that checks only the wound misses distress that was more common after a complication than after an uneventful operation.

Don't overread it

This is an association in administrative data; it does not show that complications cause mental illness.

The statistics, in plain English

An adjusted odds ratio of 1.28 (95% CI 1.24–1.32) means about 28% higher odds of a new or worse mental health disorder after a complication. In absolute terms that is 6.2% versus 4.9%, about 13 extra people per 1,000 with a complication. The large sample makes the estimate precise, but unmeasured differences between patients could explain part of it.

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