The Hidden Link Between Abdominal Surgery and Depression

When most people think about abdominal surgery, they picture the physical side of recovery: incisions healing, managing pain, adjusting diet, or regaining strength. What often goes unspoken is the emotional impact—and for many, that includes symptoms of depression. While it’s normal to focus on the physical recovery, the mental and emotional side of healing is just as important. Understanding why abdominal surgery can trigger depression helps reduce stigma and encourages people to seek support.

Surgery can affect the gut-brain connection, especially the production and function of serotonin, a key neurotransmitter involved in mood, appetite, and cognition. What many people don’t realize is that about 90% of the body’s serotonin is made in the gut. Any major disruption—like surgery—can have ripple effects on both your physical and mental health. Let’s break down how this happens.

How Surgery Disrupts Serotonin:

1. Changes to the Gut Microbiome

• Surgery, anesthesia, and antibiotics can disturb the gut’s delicate balance of bacteria (a state known as dysbiosis).

• Certain microbes, like Lactobacillus species, play a role in serotonin production.

• Research in mice shows that after surgery, a drop in these beneficial bacteria can affect both serotonin levels and behavior.

2. Inflammation and Gut Permeability

• The stress of surgery can trigger widespread inflammation and increase “leaky gut,” allowing inflammatory molecules to enter the bloodstream.

• These changes may drive neuroinflammation, which is strongly linked to depression and cognitive changes.

3. Anatomical Changes to the GI Tract

• Surgeries can change how the gut functions.

• These procedures can decrease serotonin production in the small intestine or, conversely, create unusually high serotonin spikes after meals.

• Both patterns disrupt normal signaling to the brain.

4. Impact on the Enteric Nervous System (ENS)

• Known as the body’s “second brain,” the ENS regulates gut motility and serotonin activity.

• Surgical injury or disruption can impair its ability to regulate neurotransmitters.

5. Medication Effects

• Anesthesia and antibiotics can alter the gut microbiome and serotonin balance.

• Patients taking SSRIs may experience reduced antidepressant absorption after bariatric surgery, lowering serotonin activity until doses are adjusted.

  
  

Consequences of Disrupted Serotonin:

• Mood changes: Increased risk of post-surgical depression and anxiety.

• Behavioral shifts: Changes in appetite regulation and eating patterns.

• Cognitive effects: Some patients develop postoperative cognitive dysfunction (POCD)—struggles with memory, focus, and processing.

  
  

Additional Reasons Why Depression Can Follow Abdominal Surgery:

1. Physical Trauma and Recovery

Surgery places significant stress on the body. Pain, fatigue, and reduced mobility can affect mood and contribute to feelings of helplessness. The longer the recovery, the more isolating it can feel.

2. Changes in Body Image

Abdominal surgeries—such as those involving the stomach, intestines, or ostomy creation—can alter how a person feels about their body. Adjusting to scars, changes in function, or medical devices can trigger grief, shame, or loss of confidence.

3. Disruption of Daily Life

Recovery often means time away from work, family responsibilities, or social activities. This disruption can create feelings of loneliness, frustration, and a sense of being “left behind.”

4. Impact on Digestion and Appetite

When your digestive system changes, so can your relationship with food. Restrictions, discomfort, or fear of eating may lead to stress and sadness, especially in cultures where food is tied to social connection.

5. Emotional Response to Chronic Illness

Sometimes abdominal surgery is part of managing chronic conditions such as Crohn’s disease, ulcerative colitis, cancer, Ehlers-Danlos syndrome, or diverticulitis. Coping with a long-term illness alongside recovery can intensify the emotional burden.

Signs to Watch For:

It’s normal to feel down after surgery, but if you notice these signs lasting more than a couple of weeks, it may signal depression:

• Persistent sadness or hopelessness.

• Loss of interest in activities you once enjoyed.

• Changes in sleep or appetite.

• Fatigue or lack of motivation.

• Withdrawal from loved ones.

• Feelings of worthlessness or guilt.

  
  

Supporting Emotional Healing:

• Acknowledge the emotional impact. Healing isn’t just physical—give yourself permission to grieve, process, and feel.

• Stay connected. Isolation can worsen depression. Reach out to friends, family, or support groups, even virtually.

• Seek professional help. Therapists familiar with medical trauma or chronic illness can help you cope.

• Advocate for integrated care. Let your healthcare team know about your mental health needs—emotional recovery is part of overall recovery.

• Practice self-compassion. Healing takes time, and it’s not a linear process.

  
  

Final Thoughts

Abdominal surgery doesn’t just affect the body—it can deeply impact the gut-brain connection and, in turn, a person’s mental health. Recognizing that changes in serotonin, the microbiome, and nervous system signaling can contribute to depression helps remove stigma and opens the door to proactive care.

If you or someone you love is struggling emotionally after surgery, know that it’s not “just in your head.” The gut and

brain are profoundly connected, and healing means caring for both. Both the body and the mind need care in recovery. Recognizing the connection between surgery and emotional health is the first step toward healing fully.