mental illness leads to physical illness
mental illness and physical illness are interlinked, where physical illness is the same mental illness and where mental illness is the same physical illness.
To know this, let us see how a mental illness causes physical illness, when I was in depression, I started getting many other diseases like fever.
In fact, mental illness has no direct relation to physical illness, but still mental illness has an effect on the body, because the illness of our mental state is associated with our lifestyle.
Poor mental state will probably change lifestyle and change of lifestyle will increase physical illnesses.
In this way, direct / indirect mental illness produces physical illness.