SAM Taylor-Wood’s portrait of the damaging formative years of John Lennon ends with the film’s only original Lennon song, Mother, playing over the closing credits.

That haunting lament (“Mother, you had me but I never had you”) begins with the sound of a chiming clock, and throughout this Valentine biopic the teenage Lennon is a ticking time-bomb waiting to explode.

The lyrics of Mother, as much as the memoirs of Lennon’s half-sister, Julia Baird, have shaped the directorial debut of conceptual artist and video-maker Taylor-Wood, especially the line “I couldn’t walk and I tried to run”.

The director interprets Lennon’s impatient teen years as an Oedipal love triangle, a domestic drama where John is torn between his protective guardian, Aunt Mimi, and his errant mother, the bipolar Julia.

Hence he is the Nowhere Boy of the title in a study of the influence of mothers on their sons, scripted by Matt Greenhalgh in the wake of his biopic of another troubled soul, Joy Division’s Ian Curtis, in Control.

Lennon went from nowhere to everywhere in the world’s most ubiquitous rock band, but Taylor-Wood mischievously never mentions The Beatles by name, although she does begin with Beatles references: the schoolboy Lennon (Aaron Johnson) drawing walrus doodles in his classroom and heading home past Strawberry Fields.

The year is 1955, in austere post-war Liverpool, where a wan, reluctantly bespectacled, 15-year-old Lennon is living with prudish, repressive Aunt Mimi (Kristin Scott Thomas) and kindly Uncle George (David Threlfall).

George’s death robs John of his only adult male bond and, seeking solace, he tracks down his long-absent biological mother, Julia (Anne-Marie Duff). Exciting, erratic but blighted by depression, Julia is a loose cannon in gaudiest lipstick, stirring the rock’n’roll teenage dreams in her son, buying him a guitar and telling him about Elvis and sex.

“She’s going to hurt you, you know that,” warns Mimi, and indeed Julia can only show him the stars but not guide him there. He is already a combustible force, full of teen front and adventurous individuality, but quick to reveal his vulnerability in aggressive ways. So much so that Taylor-Wood is in danger of making the protean Lennon too one-dimensional.

Rock’n’roll will be his outlet, and in its secondary strand, Nowhere Boy tantalisingly sows the seeds of The Beatles in Lennon’s nascent encounters with Paul McCartney (Thomas Sangster) and George Harrison (Sam Bell).

Johnson’s adolescent Lennon is built more on emotional, brooding expression than physical verisimilitude; Scott Thomas’s melancholic Mimi is a typically buttoned-up portrayal; Duff’s Julia is the stand-out, a bright flame but dangerously fickle too.

Taylor-Wood’s direction evokes the harsh Fifties, and she reins in her conceptual instincts to keep extraneous experimentation to a minimum and storytelling to a maximum, without yet finding her own cinematic voice.

Nowhere Boy (15), 93 minutes, Icon Home Entertainment, drama