Why speculate when you can just look it up in Google with 'francis crick lsd'? The first hit gives us a biographer's quote http://skeptics.stackexchange.com/questions/6835/was-francis...

> I am frequently asked for my opinion on the speculation that Francis Crick was on LSD when he discovered the double helix; or that he was involved with a man named Dick Kemp in the manufacture of LSD. These assertions were reported second hand in an article in the Mail on Sunday by Alun Rees following Crick's death and they have since gained a certain amount of traction on the internet. Both stories are wrong. The true story, which I was told directly by Crick's widow and by the man who (as his widow confirms) first supplied the Cricks with LSD, is much less sensational. Crick was given (not sold) LSD on several occasions from 1967 onwards by Henry Todd, who met the Cricks through his girlfriend. Todd did know Kemp, with whom he was eventually prosecuted, but the Cricks did not. As for the implausible idea that the then impoverished and conventional Crick would have had access to LSD when it was newly invented in the early 1950s, there is simply no evidence for it at all. Those who wish to argue that LSD helped Crick make discoveries should note that all his major breakthroughs in molecular biology were made before 1967.

http://www.nytimes.com/2006/07/11/science/11book.html?_r=1 confirms that the biography did cover his LSD & marijuana use.

Another link leads to this quote

> "He listened with rapt, amused attention to what I told him about the role of LSD in his Nobel Prize-winning discovery. He gave no intimation of surprise. When I had finished, he said: 'Print a word of it and I'll sue.'"

which a google leads to http://www.hallucinogens.com/lsd/francis-crick.html and we get some context:

> The arrest and conviction of Solomon, Kemp and a string of co-conspirators dominated the headlines for months. I was covering the case as a reporter at the time and it was then that I met Kemp's close friend, Garrod Harker, whose home had been raided by police but who had not been arrest ed. Harker told me that Kemp and his girlfriend Christine Bott by then in jail were hippie idealists who were completely uninterested in the money they were making....'Dick Kemp told me he met Francis Crick at Cambridge. Crick had told him that some Cambridge academics used LSD in tiny amounts as a thinking tool, to liberate them from preconceptions and let their genius wander freely to new ideas. Crick told him he had perceived the double-helix shape while on LSD. 'It was clear that Dick Kemp was highly impressed and probably bowled over by what Crick had told him. He told me that if a man like Crick, who had gone to the heart of human existence, had used LSD, then it was worth using. Crick was certainly Dick Kemp's inspiration.' Shortly afterwards I visited Crick at his home, Golden Helix, in Cambridge. He listened with rapt, amused attention to what I told him about the role of LSD in his Nobel Prize-winning discovery. He gave no intimation of surprise. When I had finished, he said: 'Print a word of it and I'll sue.'

That article is also useful for documenting his post-DNA involvement in psychedelic societies like Soma.

Since LSD was synthesized well before March 1953, was being used in psychiatric applications and research starting 1949, the window was open.

So, Crick has means , opportunity, motive, and was unquestionably using it after 1953; unfortunately, the direct evidence is two questionable persons' testimony.

So the best answer to whether LSD helped discover the double helix is: "maybe".