Major depressive disorder, commonly known as “depression,” is increasingly prevalent today, affecting approximately 17% of the global population, according to the World Health Organization. Despite its widespread nature, significant misconceptions persist about depression. This condition impacts not only emotional well-being but also physical health and social relationships. Let’s explore it in greater detail.
Depression extends beyond mere sadness, frustration, or feeling down; it profoundly impacts an individual’s daily functioning and quality of life. Early descriptions of depression can be found in ancient cultures, including Egypt, Babylon, Sumer, and China. In the 4th century BCE, Hippocrates described it as “melancholy,” stemming from black bile affecting the brain, thus establishing a link between the brain and mental health conditions for the first time.
Following this link, Aretaeus defined criteria for mania, and Jarvis conducted the first epidemiological research. The first research on prevalence emerged in the 19th century in the U.S., where, during World War II, soldiers with symptoms resembling those of so-called “hysterical women” were rejected from or discharged from military service. As our understanding evolved, the connection between depression and brain function has been continually reinforced, with particular attention paid to serotonin’s role. A. Michael Mann’s study of cerebrospinal fluid (CSF) in individuals who had died by suicide identified lower levels of certain metabolites. This research paved the way for future CSF studies, including Bessel van der Kolk’s 1980s study comparing CSF in people who died by suicide versus those who died by natural causes, finding 15 times lower serotonin levels in the former group. These findings have strengthened the understanding that depression is a treatable illness, not simply a symptom or weakness.
Depression, or “melancholy” in the closest Turkish equivalent, often entails symptoms like diminished interest, low energy, anhedonia, sleep and appetite disturbances, memory and concentration issues, and, in severe cases, pervasive thoughts of death and suicide. Not every episode of sadness or low mood equates to clinical depression; rather, depression is characterized by symptoms persisting for over two weeks, meeting specific diagnostic criteria, and warranting support or intervention if these persist.




