I was the one who first commented on Vicky and Fritz being depressed. She wrote of it in The Empress Frederick Writes to Sophie and, I believe, in one of the volumes of letters to her mother. It wasn't a clinical diagnosis (ie Fritz suffered from depression) but rather that he could be easily depressed or 'cast down' by events. This was something she saw in Sophie (and who wrote frequently of feeling depressed--her words) as well and she compared her to her father. Vicky once wrote to Sophie "He was so sensitive, and felt so deeply the injustice of his fate." This sensitivity, she believed, caused him (and she saw the same in Sophie) to be worn down by smaller sadnesses & disappointments which left them vulnerable to the bigger disappointments and tragedies. She didn't think there was a psychological, chronic condition--just a facet of their personality. She, and other women in the family, speak often of 'being low', 'depressed' and having a period of depression.
Fritz had undoubtedly been marked by his upbringing--no wonder he responded so heartily to the much different atmosphere of Victoria & Albert's family life. "Papa always said he could not bear to think of his childhood, he had been so unhappy and miserable, and had many a time wished himself out of this world."
I don't think any of this should be taken as a criticism--Fritz was human and flawed like everyone. And Vicky, who adored him above all, certainly wouldn't write anything false or harsh towards him. In EFWTS she writes on the anniversary of his death:
"'It was such a comfort to receive your dear telegram this morning. I knew your thoughts would be here, where it hardly seems possible to me, even now, that two sad years have elapsed since that dread hour, that I have lost for ever what I held most dear on earth, that my children are deprived of the best father, and the country of the one man who would have been such a blessing to it . . . his hopes and aims were noble and pure and good . . . oh, that the love and peace he sought to spread would penetrate some
hearts and make them feel what wrong they have done. . . I try to be brave I assure you, and not to think of myself, but oh! the longing for one squeeze of dear Papa's big hand, for a kiss, for the sound of his voice or his step, is so heavy, it takes all courage out of me. To face life and struggle on without him seems too hard, too incomprehensible.' "
And later: "Oh, how I miss darling Papa so cruelly, and in the morning on waking, his empty pillow, his silent and empty rooms, make me so wretched. It is no use to grieve and to mourn, but one cannot help it. How unfeeling I should be if I did not suffer this pain.' "
"I look round in vain for beloved Papa's dear face and fine tall figure, so broad and strong and handsome. The christenings of you all came so vividly before me, and I cannot believe that all the terrible things I have been through are reality and not a bad dream. . . . It is just on 33 years ago that I arrived here in Berlin, a young bride, very shy and uncomfortable, and yet it seems to me like yesterday.' "
She talks of his "dear noble face, so manly and calm". When Margaret married, and had things been different they would now be 'empty nesters' she writes "'The struggle I went through on the 25 th I shall never forget. I thought of my own wedding 3 5 years ago, and had a heart-sick longing for dear Papa, to be able to throw my arms around his
neck and say, now we are alone, in the house together once more, as we were when we were bride and bridegroom. But all was silence around me."
Frederick III is my favorite male royal and his romance with Vicky probably my favorite royal romance.