Mood Changes Because of the surgery, your diet becomes much more restrictive. This restrictive diet reduces the amount of carbohydrates you can take in, which causes serotonin levels to go down. Decreased serotonin can cause depressive symptoms. You may also deal with mood swings as a result of your low-carb diet.

Does gastric bypass have long term effects?

Bariatric surgery carries some long-term risks for patients, including: Dumping syndrome, a condition that can lead to symptoms like nausea and dizziness. Low blood sugar. Malnutrition.