The noun "depression" can be both countable and uncountable.
Meaning: a feeling of great sadness that can require medical treatment to cure
Example sentence: John's depression became much worse after his wife left him.
Meaning: a period of little economic activity when many people lose their jobs
Example sentence: There are many theories in economics about what causes depressions.
Note: A second countable meaning of "depression" is to do with the weather. In this context, a depression is a large mass of air at low pressure that can cause cold weather and rain.
Test your understanding:
- During the last economic depression, Diana lost her job.
- Her doctor prescribed some medicine for her depression.