Psychiatric Risks After Bariatric Surgery

Suicide risk rises after weight-loss surgery, and psychiatric meds need new dosing

STUDY: Sun T, Eurasian J Med 2026

STUDY TYPE: Narrative review

FUNDING: Independent

Background

This review pulls looks at how mood, suicide risk, and medication levels change after bariatric surgery.

Screening Before Surgery

Psychiatrists are often called on to screen patients before surgery, with attention to disorders that could compromise the safety of the operation or follow-up:

In addition to a full psychiatric evaulation, ask about their expectations for the operation, motivation, nutrition and eating habits, social supports, educational level, occupational status. Assess their capacity for adherence and engagement with postoperative follow-up.

Mental Health: Better and Worse

Depression and anxiety usually improve for the first 1 to 2 years (the “honeymoon phase”), as people have improved appearance and better mobility and health. However, symptoms can resurface by year 2 to 3. One 9-year study found the lifetime rate of mood disorder rose 32% afterward.

Causes of worse mood include change in hormones, disappointment in surgery, and removal of “emotional eating.” Another cause is one you can screen for: poor absorption of vitamins and minerals after surgery, particularly vitamin B12, vitamin D, and folate.

Suicide and self-harm are the most serious risk. One large cohort found suicide rates roughly triple the general populations, and a meta-analysis found self-harm and suicide attempts nearly 4 times more common than in matched controls, mostly within the first 2 to 3 years and more often after gastric bypass.

Addictions

Alcohol use disorder rises after weight loss surgery. Some patients may shift from emotional eating to drinking, but physiology also plays a role. Blood alcohol levels increase by nearly 50% in after RYGB surgery.

Outside of alcohol, research is limited, but suggests a relapse into cigarette smoking or a new disorder of opioid use disorder.

Binge Eating

Binge eating disorder generally goes down after surgery, as patients feel more full after eating. However, the problem continues for many (46% in one study), and some develop a new binge eating disorder, characterized by out-of-control eating in small amounts. This is different from post-surgery grazing, where patients eat often in small amounts, without the out-of-control experience. Grazing occurs in 17-47% of cases and may cause weight regain.

Medications: Low Levels for 6-12 Months

Gastric bypass also changes drug absorption, particularly in the first 6-12 months after surgery. SSRI and SNRI levels can drop about 25% within months, tricyclics carry added electrolyte risk, and drugs with narrow safety margins, like lithium, valproate, and carbamazepine, need closer monitoring. Extended release medications are also affected.

Practice Implications

• Monitor mood, suicide risk, addiction, and eating disorders.
• Switch to instant release (or even better, ODT, transdermal, or LAI) formulations after gastric bypass surgery for at least 6-12 months.
• Most drug levels, including antidepressants, can be checked before and after surgery.

—Chris Aiken, MD
Director, Psych Partners
Editor in Chief, Carlat Psychiatry Report

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