I have been approached by many spouses, parents and children who live with someone with depression who are sympathetic but struggle to know how to help. Depression is a very difficult disease to understand and I speak personally of my error in judgement of my mother. I have watched my father, my husband and my children attempt to cope with living with an individual suffering from depression.
The main thing I can offer is try very hard to have patience, don't discount their suffering and don't judge them. Please don't tell us to pray more, study the scriptures more and go to the temple more and our depression would diminish or leave. We have probably tried all of that and more. We have already berated ourselves that if we were more righteous we could be healed. When someone is suffering from actual chemical depression, those things are not going to help without medication.
We know that sunshine and exercise can be very therapeutic but constantly being badgered to get out in the sun more and exercise does not motivate us to leave the house and soak up the rays.Neither is suggesting that we get a job, babysit grandchildren or any other good thing you think will help. With depression, a positive mental attitude or putting mind over matter might sound like good advise but the depression inhibits any of those abilities.
Once medication has started to work we might be more receptive to occasional gentle suggestions.