Depression is a mood disorder. According to the World Health Organization, it is a leading cause of disability worldwide and is a significant contributor to the overall global burden of disease. Approximately 280 million people worldwide suffer from depression. Common symptoms of depression include persistent feelings of sadness, anxiety, an “empty” mood, changes in appetite, over-sleeping, difficulty in thinking and increased fatigue. Recognizing the large-scale impact that depression has on quality of life calls for holistic strategies to better improve the health outcomes of individuals suffering from this disorder.

One such method is the use of food and food supplements to improve mental health (also referred to as nutritional psychiatry). We have previously discussed the interconnectedness between the gut and the brain and made connections drawing from scientific journals to elucidate the crosstalk that exists between them through certain metabolic activities like altered levels of gamma-aminobutyric acid (GABA) and inflammation and how these events are modulated by bacteria—all of which contribute to how we feel.

Depression Symptoms Expanded

Depression is a complex and multifaceted disorder, and its symptoms can vary significantly from person to person. However, several common signs are generally associated with depression. These symptoms can disrupt daily life, impact relationships, and severely diminish a person's overall quality of life. It’s essential to recognize these signs early so that timely intervention and treatment can be sought. Below are the explained symptoms of depression:

1. Persistent Sadness or Low Mood: One of the most defining symptoms of depression is a prolonged period of sadness or a low mood that does not seem to improve over time. This persistent emotional state often feels overwhelming and may occur without any clear cause. People with depression may find themselves unable to experience joy or pleasure in activities that once brought them happiness. This emotional numbness can be isolating and discouraging, contributing to the feeling of being trapped in a cycle of negative emotions.
2. Loss of Interest or Pleasure in Activities: Known as anhedonia, this symptom involves a significant reduction in interest or pleasure in activities that were once enjoyable or fulfilling. Hobbies, socializing, or even basic daily tasks may no longer feel rewarding. This lack of motivation can extend to personal and professional areas of life, leading to neglect of responsibilities and relationships. It’s common for individuals with depression to withdraw from friends, family, and activities they once loved, which only intensifies feelings of isolation.
3. Changes in Appetite: Depression can have a profound effect on eating habits, leading to either a loss of appetite or an increase in food intake. Some individuals may stop eating altogether, leading to weight loss and potential malnutrition, while others may find comfort in overeating, leading to weight gain. These fluctuations in appetite are often accompanied by a sense of dissatisfaction or guilt about eating habits, further affecting emotional well-being. The changes in appetite can also interfere with the body's overall health, further complicating the mental health struggle.
4. Sleep Disturbances: Depression frequently disrupts normal sleep patterns. Individuals may experience insomnia, where they struggle to fall asleep or stay asleep, or hypersomnia, which involves excessive sleepiness and the need for long hours of rest. Despite spending more time in bed, individuals with depression often wake up feeling unrefreshed and fatigued. These sleep disturbances not only worsen symptoms of depression but can also create a cycle of poor sleep and emotional distress, making it difficult to break free from the condition.
5. Fatigue or Low Energy: A sense of constant fatigue or low energy is another key symptom of depression. Even after a full night’s sleep, individuals may feel exhausted and drained throughout the day. This overwhelming tiredness can make even the simplest tasks feel like monumental efforts. As a result, daily activities such as work, exercise, or social interaction may be put on hold, contributing to feelings of worthlessness or frustration.
6. Difficulty Concentrating or Making Decisions: Depression often impairs cognitive functions, making it harder for individuals to focus, think clearly, or make decisions. This "brain fog" can be particularly noticeable in the workplace or academic settings, where concentration is crucial. People with depression may find it difficult to stay engaged in conversations or follow through with plans. This lack of mental clarity can make individuals feel incompetent and hinder their ability to function efficiently in daily life.
7. Feelings of Guilt or Worthlessness: Individuals with depression may experience persistent feelings of guilt, shame, or worthlessness. They may blame themselves for things that are not their fault or feel undeserving of love or support. These negative self-perceptions can fuel a cycle of self-criticism and deepen depression. Feelings of inadequacy and low self-esteem are often accompanied by a sense of helplessness, which can make it impossible to overcome the disorder without external support.
8. Increased Irritability or Restlessness: While depression is commonly associated with sadness or low energy, it can also manifest as irritability or restlessness. People with depression may find themselves easily frustrated, angered, or upset over things that would not have bothered them in the past. This heightened irritability can strain relationships and lead to more isolation. In some cases, restlessness may also make it hard to relax, further exacerbating symptoms of anxiety and depression.
9. Physical Symptoms Without Clear Cause: Depression often manifests physically, leading to symptoms such as unexplained headaches, stomach aches, muscle pain, or other chronic physical complaints. These physical symptoms may not have a clear medical cause and can lead to further distress, as individuals seek answers for their discomfort. The mind-body connection plays a significant role here—depression can cause significant changes in physical health, which in turn worsens mental well-being.
10. Recurrent Thoughts of Death or Suicidal: In the most severe cases, depression can lead to thoughts of death or suicide. Individuals with depression may feel as though life is not worth living, and they may fantasize about escaping the emotional pain. This can also extend to thoughts of harming oneself or attempting suicide. These feelings are incredibly serious, and immediate medical attention or intervention is necessary if someone experiences thoughts of self-harm or suicide.

How can Nutritional Psychiatry help with Depression?

Nutritional psychiatry focuses on leveraging food and dietary supplements as complementary approaches to treating mental health disorders. Traditional treatments for conditions ranging from psychotic disorders like schizophrenia to neurodegenerative diseases such as dementia primarily aim to manage symptoms. While these treatments can be effective, they often come with significant side effects that may impact patients' quality of life.

In recent years, research into the connection between diet and mental health has gained substantial momentum. This growing body of work highlights the potential of nutrition-based interventions as an alternative or complementary approach to managing psychiatric conditions. Studies have identified key areas of focus, such as the role of the gut microbiome and the impact of nutrient deficiencies on mental health. The findings from these studies are promising, offering valuable insights into how targeted dietary strategies can support mental well-being and improve outcomes for individuals with psychiatric disorders.

Balanced Diet for Depression: A Key to Mental Health

The idea of a balanced diet has always been a way to maintain the proper functioning of the human body. Therefore, consuming healthy food in appropriate proportions is known to provide certain benefits. The Mediterranean diet has been extensively studied and linked to its possible role in positively altering an individual’s mood. The Mediterranean diet is a diet emphasizing plant-based foods and healthy fats which may support brain function.

In a study by scientists to establish the effect of the Mediterranean diet on mood change, a randomized population of young adults was categorized into groups that took Mediterranean diets and those that did not. Ten days following the experiment, individuals who took the Mediterranean diet reported an elevation in their mood. Another clinical study that involved an adult population taking the Mediterranean diet resulted in a similar pattern of mood increase which led to the conclusion that an intake of a high-quality diet like the Mediterranean diet can lower the risk of depression. However, what is the underlying mechanism behind such a relationship, and how can the foods in the Mediterranean diet influence an elevation in the mood of individuals living with depression?

In describing the gut-brain axis, one of the several ways that the brain interprets how we feel is a response to the secondary effect of gut inflammation. High-fat foods, i.e., food with high levels of cholesterol, have been implicated in causing the inflammation of the gut, which can induce the feeling of tiredness, and sad or empty mood - symptoms experienced by people living with depression. Consuming diets of high quality with anti-inflammatory properties and an increased supply of antioxidants may reduce systemic inflammation and oxidative stress, potentially decreasing depressive symptoms. Moreso, individuals living with depression have also been reported to experience increased levels of cortisol production, decreased levels of brain-derived neurotrophic factor (BDNF), and impaired mitochondrial ATP production. Studies have found that diets rich in vitamins, polyphenol compounds, and omega-3 fatty acids alter these physiological pathways, to alleviate depressive symptoms. Therefore, consuming food rich in these compounds may play a vital role in improving the health outcomes of people living with depression.

In conclusion, through the intake of high-quality diets, one can reduce the physiological effects of depression-linked biochemical pathways such as gut immune cell activation, amino acid metabolism, systemic BDNF levels, and the production of vitamins and neurotransmitters. So, the next time you are eating that healthy meal, think about its far-reaching effect, not only on your gut health but on your mental health as well.