Which neurotransmitter's deficiencies are most commonly linked to anxiety and depression?

The link between serotonin deficiencies and mood disorders such as anxiety and depression is well-documented in both clinical and research settings. Serotonin is a key neurotransmitter that plays a critical role in regulating mood, emotional stability, and overall psychological well-being. When serotonin levels are low, individuals may experience an array of symptoms consistent with anxiety and depression, including feelings of sadness, irritability, and a lack of interest in activities they once enjoyed.

Research has shown that many effective antidepressant medications, particularly selective serotonin reuptake inhibitors (SSRIs), work by increasing the availability of serotonin in the brain, which helps alleviate depressive and anxious symptoms. This relationship underscores the importance of serotonin in mood regulation.

While other neurotransmitters like dopamine, norepinephrine, and acetylcholine also influence mood and cognitive functions, the predominant focus for anxiety and depression treatments often revolves around serotonin. This connection is especially emphasized in the context of understanding the biological underpinnings of these mental health conditions.