Depression

A mental disorder characterized by the presence of sadness, loss of pleasure, feelings of guilt and low self-esteem, accompanied with alterations in the sleep pattern and the appetite, lack of concentration, and feelings of being tired, which can become chronic and recurrent, making the person dysfunctional in their daily activities; when it is mild it can be treated with psychotherapy, but when it is moderate or severe, pharmacological treatment may be needed.

Reference:

Bernard, J. E. R. (2018). Depression: A review of its definition. MOJ Addict Med Ther, 5(1), 6-7. https://doi.org/10.15406/mojamt.2018.05.00082