Released September 2008, The Black Balloon, winner of the 2008 Berlin International Film Festival, had its UK début at the Edinburgh International Film Festival in June 2008. The writer and director Elissa Down was present to answer questions after the screening.

The film explores the dynamics of a military family, the Mollisons, whose teenage son Charlie has an autism-spectrum disorder. The narrative of the disruption caused by the family's move to a new area and the mother's (Maggie, played by Toni Collette) pregnancy, is delivered by Charlie's 15-year-old brother, Thomas (Rhys Wakfield).

The film clearly portrays the core features of autism-spectrum disorder. Charlie's deficits in social interaction shine through as we watch Thomas's completely ‘neurotypical’ developing romance with Jackie (Gemma Ward). Thomas and Jackie's reciprocal gaze, body language and use of nuance are all at stark contrast to Charlie's clear frustrations regarding social appropriateness, shown at its best when he runs off with Jackie's school bag, to be later found chewing one of her tampons, with no comprehension of his brother's embarrassment.

Communication is a further difficulty: Charlie ‘signs’, which perhaps obscures the extent to which language, or the misinterpretation of meaning, can be an issue. Thomas's frustrations at the limitations this imposes are clear, reinforcing the underlying point. The matter of routine and the challenges of new situations are demonstrated at the outset as the family move house and Charlie heralds their arrival by sitting on the front lawn, banging a wooden spoon and wailing, demonstrating both his distress at his situation and his difficulties articulating this.

The film is set in the early 1990s when less was known about developmental disorders and services were less well established. However, there is a notable absence of professional input and the family copes as best they can, explicitly accepting that they must sacrifice to care for Charlie. This is regrettable, as Charlie would have likely benefited from speech and language therapy and behavioural psychology input, which could have mitigated the impact of his more challenging behaviours. In one scene, Charlie is found rubbing excrement into his bedroom carpet, which his pre-eclamptic mother and brother clean up, the latter horrified when he realises his girlfriend has witnessed the scene. This also reminds us of the often huge responsibility for providing care and support that falls on siblings, sometimes overshadowing their own developmental and emotional needs.

The writer, Elissa Down, has two brothers who have autism-spectrum disorder and the script is based on her own experiences growing up, which gives the film a ‘matter-of-fact’ quality. There is also a genuine emotional warmth – Thomas's love for his brother resonates despite his daily prayers that Charlie should be ‘normal’, and there is one scene where he empathically mirrors Charlie's ‘communication style’ to excellent effect.

In short, The Black Balloon is good cinema and an excellent primer for discussing the issues relevant to individuals with autism-spectrum disorder and their carers, as well as professionals with a clinical responsibility of care in the field; as such, I recommend it.