In short, the difference between depression and bipolar disorders (there are more than one) is:
- Depressed people struggle with low mood
- People with bipolar disorder struggle with extreme fluctuations in mood – usually both highs and lows.
Depression is a mood disorder characterized by low mood, loss of interest in activities, feelings of hopelessness, excessive guilt, sleep and appetite changes, frequent thoughts about death or suicide and concentration difficulties. A depressive episode lasts for a minimum of two weeks, but usually for much longer.
Bipolar disorders are different. While most people with bipolar disorders experience periods of depression, they also struggle with periods of mania and/or hypomania.
To be diagnosed with bipolar I disorder, a person must have experienced at least one episode of mania. And to be diagnosed with bipolar II disorder, the person must have experienced at least one episode of hypomania and one depressive episode.
Read more about the symptoms of mania and hypomania: What are the symptoms of bipolar disorder?