Psychology of feeling depressed in winter and gloomy weather in a young man

A 26 year old man reported that with approaching winter his mood is going down. Till Spring comes, he wants to just stay inside the house. He finds it difficult to tolerate the dark and gloomy weather. Outside feels cold. The overcast skies and lack of sun makes him feel listless. He claimed without the sun he has a bad attitude. He attributed his problems to suffering from "the winter blues" and wondered if he should get "serotonin light therapy". He claimed that there are lamps which emit light that raises your serotonin, the lack of which is behind depression. He also wondered if he should take 5HTP pills, along with St. John's wort. He talked about going to the chiropractor to boost up his morale. He wanted my opinion if high doses of Vitamin D would be a possible antidote to his "SAD" - Seasonal Affective Disorder.
He also attributed his addiction to narcotics -Vicodin - which goes out of control during winter as an attempt to create warmth inside him. When I go out in winter I can feel the chill penetrating right into my marrow. The Vicodins wipe out that feeling. I feel warm and confident and ready to face the world.

The patient suffers from remarkable inhibitions in all areas of life despite having superior intelligence. He attributes it to heredity and declares that his father and his aunts have the same problems. "We are all shy and inhibited. We lack confidence."
He claimed he is so inhibited that he cannot even go to the toilet freely if he is in uncomfortable surroundings, including his parents home, where he still lives and never feels at home. When I conjectured that he is uncomfortable there because he has disturbed relationship with his father, he outright rejected that construction, claiming that he has great relationship with his father, only to proceed on to indirectly confirm the accuracy of my construction by saying that he does have disturbed relationship with his siblings, one of whom broke his nose. The ambivalence towards his father had long ago gotten displaced to his brothers.
He stated that he has to take laxatives to goad his inhibited bowels. But remarkably the lax bowels resume their normal tone when he is staying at his girlfriend's house. So, he declared, there is something psychological rather than physical that keeps his bowels inhibited.
When the construction was made that his lack of confidence was because he feels he lacks the psychological support of his father - symbolized by the sun - and he feels completely not up to par to face the world without his father/sun with him, he was stunned. He said that he had always felt that, and had arrived by his own independent thinking that his feeling of inadequacy in cold and gloomy weather has to do with not feeling man enough, but he had never expressed it to anybody because of the fear of appearing crazy. It was easier to rationalize his problems as "Seasonal Affective Disorder."
The patient agreed that his searching for Vitamin D, 5-HTP, chiropractitioners, different therapists, and other esoteric objects also was an attempt to get "phallic potency", which he felt he had not received enough from his father. Bright shining sun nullified best this feeling of inadequacy, hence he felt good in summers.
That his inhibitions had to do with excessive sensitivity to pain, which had made him shy in interacting with other men to avoid getting hurt, and this lack of robust relationship with men in general, was behind his feelings of phallic inadequacy, and when he took Vicodin the fear of pain disappeared, enabling him to face the world and other men, was conjectured but not explored with the patient.