Well, it is mid-May when SADS diminishes. I hope somebody even sees this!
I did some anecdotal studies on SADS of my own and there seems to be two types. One type is why the acronym "Seasonal Affective Disorder" was chosen - SADS for feeling sad. The other is being just plain sleepy and not being able to get going in the morning and then falling asleep early, plus having an enormous insatiable appetite for fats and sweets from October to April. With that goes a spike in sex drive in August at harvest time. I have the just plain sleepy type SADS, which I call SAM for Seasonal Adaptive Metabolism - I am NEVER, EVER SAD! I just can't wake up.
I live in the U.S. and I found a lot of problems getting physicians to understand how real and severe it can be for us Scandinavians and other far-northern Europeans. I also knew quite a few Japanese-Americans when I was a kid and they also complained of SADS-like problems more-so than most Caucasians. When I go see a new doctor and fill out the intake forms, I put "other" for race or ethnicity and list Scandinavian because I firmly believe our differences are enough that we should not be lumped in with Sicilians when it comes to general health considerations, including lighting requirements in wintertime. Anyway, SADS and SAM (for Seasonal Adaptable Metabolism) can both be controlled quite effectively with alcohol. That is how I controlled it, among many other problems, for 25 years, and how other Scandinavians have done it for thousands of years. Too bad it has such unthinkably horrible side effects that go with the cure! I discovered that sleeping with my bedroom brightly lighted all year just about cured me (not of being a drunk, just SADS) - thank goodness for low wattage L.E.D. lights that help keep my light bill tolerable! If anyone sleeps in your room and doesn't like the lights on, I don't know what to tell you to do, there is no compromise. That is like trying to find a compromise on whether to be dead or alive, there is no in between.
I hope a solution can be found for your son, I was a professional but functional drunk for 25 years. I quit drinking when I found out and cured the several problems that I was using alcohol to self-medicate for. I quit when I found what my problems were and then found competent help to get them solved. The operative words here are "I FOUND". "You can lead a drunk from drink, but you can't make'm think". No one but the alcoholic him/herself can do that, and the desire has to be there to take on that task and work at it diligently. I wish it were that way for others, there are a bazillion kinds of drunks, it is not one-size-fits-all condition. The only thing that is one-size-fits-all about alcoholism is the inevitable six foot deep hole or celedon-green urn on the fireplace mantle.