What health issue is linked with a deficiency in serotonin?

Serotonin is a neurotransmitter that plays a significant role in regulating mood, emotions, and various bodily functions. A deficiency in serotonin is most closely associated with depression. This stems from numerous studies and clinical observations that indicate low levels of serotonin can lead to feelings of sadness, hopelessness, and a lack of interest in activities, all of which are key symptoms of depressive disorders.

In treating depression, many medications, known as selective serotonin reuptake inhibitors (SSRIs), function by increasing serotonin levels in the brain, which further supports the link between serotonin deficiency and depression. While anxiety can also be influenced by serotonin levels, it is primarily linked to other neurotransmitters, such as gamma-aminobutyric acid (GABA). Other options like memory loss and pain sensation are associated with different biological mechanisms and conditions that do not have a direct correlation with serotonin deficiency in the same way that depression does.