Watching this at the moment - know how it ends (of course the average length of a manic episode is about 6 months anyway) - might share my thoughts later.
So, not a bad film (certainly better and more interesting than Poppy Shakespeare), a bit of background: It's the story of a junior doctor who has a past diagnosis of bipolar disorder (manic-depression) and appears to be having a psychotic episode (including suicidal command hallucinations). She's naturally not allowed to work as a doctor and is currently trying to get over the episode and back to work, who she needs to convince she is safe and taking her medication, but clinical psychologist (and recovered schizophrenic) Rufus May is helping her to recover without medication (May gives the background here). Naturally they don't show the real doctor but instead she is played by an actor, Rufus May apparently plays himself.
Her symptoms don't appear to include overactivity or other typical manic symptoms (more like a mixed episode maybe), they seem to be mainly hallucinations of some sort (it is never established if they are true hallucinations), mostly a single voice talking to her, and some fairly transitory delusions, including persecution, reference, and grandiosity. She also appears to have a history of self harm and there is some family bereavement (but no other social or family information). May himself seems a rather volatile and 'interesting' personality (I don't think I'll say any more than that).
After over six months of May's therapy (they're never clear what that exactly involves but from his comments I take it that it is somewhat psychodynamic, perhaps a bit cognitive, see here) which seems to involves her getting worse rather than better (she starts off with mostly the hallucinations) she fools the hospital review board and returns to work as a doctor. They imply that they have some kind of breakthrough where she 'discovers' the voice is someone who bullied her at school, and that she is then able to deal with the voice (although she seemed to deal with it ok before the breakthrough) and she still has the voice at the end (this is potentially less worrying than it sounds, I've met a few patients recovered from psychotic illness with residual voices that I'd be happy practising medicine).
Obviously you can't make a diagnosis from a dramatisation, but you'd want to consider a personality disorder, affective disorders like depression, bipolar, and schizoaffective disorder, and obviously schizophrenia. It is difficult to see what the current episode is supposed to be, she isn't very manic, her mood seemed low, but she was certainly somewhat psychotic with some grandiosity.
So how revolutionary is this treatment from Rufus May then? Well the average length of a depressive or manic episode is six months, so I'd say taking over 6 months for remission plus continuing residual symptoms is not exactly spectacular, particularly given that we know both depression and psychotic symptoms will respond to CBT. I suppose she wasn't hospitalised, and the psychiatrist (Trevor Turner) in the piece indicates that he would probably have sectioned someone with these symptoms and refusing medication if necessary to bring them into hospital*. On the other hand, Rufus May sails rather close to the wind with her safety, and looks pretty worried at one point, whereas most psychiatrists would be held legally liable for that sort of behaviour, which is why they are rather more cautious about suicide risk (May says at one point, 'she's only a risk to herself' - which is really rather the point, although she also says the voices tell her to kill others, and I don't think I'd have been too happy being her patient while she had her delusion about having a cure for AIDS, or that a fish tank was an ECG).
Plenty of doctors have bipolar disorder so there's no reason to think she can't function as one, the real question is whether she's going to relapse - you'll expect most bipolar people to relapse at some point, on average every couple of years. A good psychoeducation programme will help you to identify early signs of relapse early enough to take action (e.g. sorting out your sleep to avoid a manic episode) so let's hope she's been given these skills by May. Drug prophylaxis has a proven benefit in reducing relapse, and residual symptoms are a poor prognostic indicator, let's hope she's ok, but until we know she's 'cured' (which will take years) you can't really conclude anything.
* Actually I think if he'd actually seen her, rather than just heard a hypothetical description by a TV producer, he would have seen that she actually had pretty good control and insight, resisting the voice and delusions, and managing to hold down a job as a care assistant. But she'd probably have benefitted from engagement with local mental health services with crisis team involvement checking up on her everyday and access to formal psychological therapy rather than being managed at arms length by someone in Bradford.