Can there be such a thing as purely physical depression?

Maybe for some: Some people lack words for their feelings, and may be unaware of emotions that accompany their lack of interest, slowed-down energy, poor concentration, loss of appetite, sleep disturbance, etc. These people may insist they are not "depressed, " yet they have the genetics and the entire symptom list of depression. We are whole beings, and mind and body are interwoven -- even if we're unaware.