The number of people living with depression in England has increased by nearly half a million in three years, according to an analysis of NHS data.
The total number for 2010-11 stood at 4.7 million people.
Data analysis firm SSentif said there was also a large increase in the number of prescriptions for anti-depressants.
Charities said more people were speaking to their GP about depression, but the figure was likely to be the "tip of the iceberg".
The data suggested the largest percentage increase was in Yorkshire and the Humber, where the number of registered cases increased by 19%.
SSentif managing director Judy Aldred said: "We have to remember that the real numbers are likely to be much higher as many people do not seek GP support."
Depression Alliance chief executive Emer O'Neill said: "We're still at the tip of the iceberg of what the figure could be."
She said more people were being affected by job losses and relationship breakdowns in the current economic climate.
However, she said there had been a shift in society's perceptions of depression and doctors had become better at diagnosing it.
"More people are coming forwards and they are coming forward because the level of support is better," she said.