Depression is indeed classified as a mental disorder, also commonly called a mental illness.
It is a mental disorder that affects approximately 5% of adults worldwide. For various reasons, it’s 50% more common in women than men.
Unfortunately, more than 700,000 people die by committing suicide every year due to the mental suffering it generates. And even though there are treatments that are scientifically proven to be effective, more than 75% of people in low- and middle-income countries receive no professional care or aid.
It is recognized in major diagnostic manuals such as the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), published by the American Psychiatric Association, and the International Classification of Diseases (ICD-11) by the World Health Organization.