Sadness and depression are often confused as both are considered the same but are not. There's a thin line that differentiates the two and understanding this difference may help process both in a healthier way.
People who are sad often think that they are depressed while people with depression ignore their symptoms and think they are just sad. However, sadness can be a major part of depression but the vice-versa is not considerable.
Anyone can be sad. Sadness is an emotion or say, a basic human nature that depends on situations. For example, you get sad when you fail in exams, someone close to you dies, had a breakup, lost your job or had some conflicts at home. The feeling of disappointment or mood change due to the above factors can make you sad.
The sad feeling may affect you for a few days but eventually, you get back to a normal routine. To say, almost every person experience sad moments on a daily basis, maybe for a minute or an hour but later they get back to their normal life. Also, the emotion goes away when you cry or talk to others. The thing about sadness is it fades with time. Moreover, sadness does not trigger other symptoms such as hopelessness.
Persistent sadness could be a major sign of depression.
Depression is a type of mental illness, unlike sadness which is an emotion. Many people don't even realise their depression until the feeling totally overpowers them.
Depression persists for a longer period and affects a person's day-to-day life. This is because depression comes not only with persistent sadness but also with other signs such as lack of motivation, change in eating patterns, sleeping problems, agitation, irritation, weight loss, difficulty in decision-making, loss of enthusiasm, loss of interest, extreme headache and fatigue, feeling of worthlessness, concentration problems and even continuous suicidal thoughts.
The state of depression not only comes with sad moments like death of loved ones, financial crisis or relationship problems, but stays with a person all the time and at every situation. Also, people with depression often lose control of their feeling and emotions, and even after crying and talking to loved ones, they struggle to go back to their normal lives.
Depression is diagnosed by Diagnostic and Statistical Manual of Mental Disorders (DSM-IV), a standard set of criteria used by medical professionals to diagnose a mental disorder.
If a person is sad for more than two weeks, it is a sign of depressive disorder and a person must consult a medical expert soon for counselling or medications.