My husband has had symptoms of depression that only last from jan/july, for 4 yrs now, why only this time of year? Can it be something else?

It could be. Seasonal affective disorder which is a type of depression related to sunlight.
Seasonal Disorder. Sometimes people have symptoms of depression that are seasonal. This is called seasonal affective disorder. Usually the worst season is the winter. It is thought to be linked to low exposure to sunlight. People will often use light boxes to help their symptoms.