I want to know what is the difference between "depression", "feeling down", and "having a depression"?

Difference: We all feel depressed or down from time to time. Clinical depression lasts at least 2 weeks.Symptoms of depression can include: feeling sad, irritable or angry. There can be a decrease in sex drive. Energy level & motivation levels may drop. One may socially isolate or stop involvement in normal activities. Sleep may increase or decrease. Weight can change in relation to increase or decrease >>.