People with depression often have worse physical health, as well as worse self-perceived health, than those without depression.
Depression and other physical health conditions have separate but additive effects on well-being. For example, the combination of heart disease and depression can cause twice the reduction in social interaction than either condition alone.
Patients with both depression and physical health problems are at particular risk: The physical problem can complicate depression’s assessment and treatment by masking or mimicking its symptoms.
It can work the other way as well. People with any chronic physical disease tend to feel more psychological distress than do healthy people. Poor physical health brings an increased risk of depression, as do the social and relationship problems that are very common among chronically ill patients.