Depression, Inflammation and Brain Fat

Over more than two decades of clinical practice, I have learned to pay close attention to cholesterol levels when working with patients experiencing depression.

This is not a conversation most people expect to hear. For years we were taught that lower cholesterol was always better. The message was clear and simple. Reduce cholesterol to protect health.

But clinical experience and emerging research tell a more nuanced story.

Cholesterol is not simply a cardiovascular marker. It is an essential structural and hormonal molecule. The brain is one of the most cholesterol rich organs in the body, relying on it to maintain the integrity of cell membranes and the stability of receptors that allow neurotransmitters to function effectively.

Cholesterol is also the starting point for vitamin D and every steroid hormone in the human body, including cortisol, progesterone, oestrogen and testosterone. When cholesterol becomes very low, the entire hormonal landscape can be affected, and mood often reflects this imbalance.

In practice, I have seen patients with persistent depression, emotional numbness, low motivation and increased vulnerability to stress who present with very low cholesterol levels. Often this has never been considered relevant to their mental health.

What is striking is that when we address nutritional intake, improve fat digestion, and support healthy cholesterol balance, mood frequently improves even when cholesterol numbers themselves do not rise dramatically. This tells us that the story is not simply about a number on a blood test. It is about how the body is using fats and how the brain is being nourished.

Research over several decades has shown an association between very low cholesterol and more severe mood disturbance. At the far end of that spectrum, low cholesterol has also been linked to increased suicide risk, which we can view not as the focus of the conversation but as an important clinical marker of severity.

For me, this reinforces an important principle. Depression is not only psychological. It is also biological.

When we ignore the biological terrain, we risk missing opportunities for meaningful improvement.

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