A documentary about the late literary tearaway Hunter S Thompson is a satisfying chronicle of how the 'good doctor' clawed away at the establishment with his delicious dark, twisted writing.

In Gonzo: The Life and Work of Dr Hunter SThompson, director Alex Gibney attempts to explain the birth of gonzo journalism - in which participatory journalism evolved into an art form whereby reality is filtered through a perverse prism - and why the writer shot himself at home in Aspen, Colorado, in 2005, aged 67.

The film is a collage of talking heads, interviews, photographs, audio recordings, animation sequences, deliberately low-fi reconstructions, illustrations, archive TV footage, a filmed book reading by Johnny Depp, who played Hunter in the 1998 film Fear and Loathing in Las Vegas, and excerpts from that and another Thompson film starring Bill Murray, Where The Buffalos Roam.

It proves that Thompson possessed an absolutely biting and sometimes savage turn of phrase with which he accurately recorded the world as he and British illustrator, and partner-in-crime, Ralph Steadman barreled through life fuelled by alcohol, drugs, rage and necessity.

Gonzo! explores the origin of his breakthrough novel, Hell Angels, which charted life with a chapter of the notorious motorcycle gang, through the first gonzo piece of writing, The Kentucky Derby is Decadent and Depraved, as well as the much-lauded political observation, Fear and Loathing on the Campaign Trail of '72, which launched him towards stardom.

Thompson's reckless, excessive and unrepetent lifestyle is of the kind ordinary men and women secretly dream about but could never sensibly carry through; he would say things about politicians that no one else dare even mutter and launch into assignments without any appreciation of the consequences... or the deadline.

Gonzo! is full of fascinating and raw evidence - taped recordings, videos and text lifted from private manuscripts - stitched together to produce a commentary narrative. However, this presents problems. There is so much fresh material that the audience is left wanting to see more of the anecdotal stories hidden since the middle of the last century.

Simultaneously, the film fails to mention some of the most iconic and well-documented gonzo stories or his intriguing beginnings in the trade.

I feel Alex Gibney dwells too long on the wider story of the 1972 US presidential election, losing focus on Thompson the man, and makes too-obvious and needless comparisons between the Vietnam war and the current Iraq conflict; screentime that could be put to better use with the rock-and-roll writer's revelations.

Overall, the two-hour documentary is a terrific celebration of Thompson - a thin, short-haired correspondent sporting his usual attire of croupier visor, oranged-tinted aviator sunglasses and patterned shirt - but for more avid fans, such as I am, it is not comprehensive enough.

As Thompson said himself: "Buy the ticket, take the ride."

Gonzo: The Life and Work of Dr Hunter SThompson (15 certificate) can be seen from tomorrow (Friday) until next Tuesday at The Tricycle Theatre in High Road, Kilburn.

Call the box office on 020 7328 1000 or book online at www.tricycle.co.uk .