Despite all recent discussions and disclaimers, the show has shown clearly that Sherlock is a love story in the sense that Sherlock needs John so much that without him in his life he infallibly turns to drugs.
True, when we meet Sherlock he seems to be clean but both Lestrade and Jeff Hope mention his addiction from early on. He may have found another outlet in solving crimes but we get the impression that his drug use is not too far in the past.
FromASiPtoHLV we do not get a single instance of voluntary drug use on Sherlock’s part. He is drugged by Irene against his will, he falls victim to the Baskerville drug by chance. We do not get any evidence for Sherlock taking drugs during his absence after TRFand the explanation is simple: He is working towards his return, he is fully expecting to continue his life with John in Baker Street so he must be at the height of his game. Consequently no drugs.
So let us look at the three instances in which Sherlock voluntarily drugs himself:
HLV after John has married and taken up his life with Mary. He still claims that it was for a case though we know (as Canon tells us) that drugs are a substitute for a life with John Watson. Being married to his work is not enough anymore.
TAB: This has been discussed thoroughly. The only rational explanation for his OD is that he has to say goodbye to John again. This time with the knowledge that he will not return. Of course he pretends that it was for a case but we know that he can enter his MP without shooting up.
TLD:And even in S4 the pattern continues. Sherlock believes he has lost John who blames him for Mary’s death and wants anyone to help him rather than Sherlock. True, Mary tells Sherlock to endanger himself in order to wake up John from his grieving stupor, but he could have chosen a dangerous case like Culverton Smith without almost killing himself with drugs.
We get three situations where Sherlock feels he has lost John - to marriage, to his own death in Eastern Europe, to John’s grief - and every time the same thing happens: he drugs himself.
This may not be healthy or reasonable - it is about the conclusion we may draw:
#sherlocklives means #johnwatsonlives. - He’s like a drug.
