Depression

Depression: More Than Just a Bad Mood

Depression is not simply sadness or a temporary bad mood. It is a serious medical condition, a mood disorder that causes a persistent feeling of hopelessness, loss of interest in life, and affects how you think, feel, and behave. Unlike ordinary sadness, depression is prolonged, significantly disrupts daily functioning, and does not go away “on its own.” It is an illness that requires diagnosis and treatment just like diabetes or hypertension.

What Happens in the Brain During Depression?

It is believed that depression is rooted in a complex set of biological changes in the brain. A key role is played by an imbalance of neurotransmitters—chemical substances that neurons use to communicate with each other. Most often this involves a deficiency or dysregulation of:

• Serotonin: Regulates mood, appetite, sleep.
• Norepinephrine: Influences energy and concentration.
• Dopamine: Associated with motivation and the feeling of pleasure.

Research also shows changes in the structure and function of certain brain regions, such as the hippocampus and prefrontal cortex, as well as disturbances in the stress‑response system.

Main Symptoms of Depression

For a diagnosis, symptoms must persist for at least two weeks. Key symptoms include:

• Depressed mood for most of the day, nearly every day.
• Anhedonia: Marked reduction in interest or pleasure in all or almost all activities.
• Changes in appetite or weight, insomnia or excessive sleepiness, constant fatigue.
• Feelings of worthlessness or excessive guilt.
• Difficulty concentrating.
• Thoughts of death or suicide.

Depression can have specific manifestations in certain groups, for example, postpartum depression in women.