Without presuming to psychoanalyse Damian McBride, I imagine he is upset about the way he has been condemned by colleagues he recently believed to be friends. Has he considered therapy to help deal with feelings which may surface in the shape of obscenities, incontinent rage or other forms of unacceptable behaviour? By way of a first step, he might want to consult a new work by one of the country's best-known psychotherapists. "If you are beset by clouds, do not despair," writes Derek Draper, in a characteristic line from Life Support. "It may be hard to believe, but behind them your own personal sun is still shining, waiting to burst through." None the less, Mr McBride will want to delve deeper into his "negative dynamics", as Draper calls them in a chapter called "Dealing with the Past". Are we talking about all-round gittishness here? Or could we be dealing with something buried in McBride's childhood?

From his own trusted supervisor, Susie Orbach, Mr Draper says he has learnt to ask, in a negative dynamic situation, if "anything else might be going on". In Draper's case, he and Susie were trying to understand feelings of hostility towards Tony Blair, a man who was once his friend. "So if you find yourself in a similar cycle of conflict, try and step aside from it for a moment and ask yourself that question: what does this person (or thing) mean to me?"

With a bit of effort, McBride may not need to undergo therapy. "Some people," writes Draper, "find that writing down their thoughts and feelings, either in a journal or just on a piece of paper, can stimulate greater understanding of why we do what we do." In his case, routes to self-knowledge include the multiple, cross-referenced promotional identities featured on derekdraper.net and his contributions on LabourList, Twitter, Facebook, YouTube, his incessant interventions on rival blogs ("I ask that you correct your original post by midday today or I will place this matter in the hands of my lawyers Schillings") and the Draper-packed pages of Life Support

However useless this assortment of banalities might be, Draper presumably derives comfort from setting down thoughts and feelings about himself: his fascination with celebrities, for instance, his birthday musings ("happy birthday to me!") or his agonies over a "major rejection". "Prior to that moment I'd been on a high," he writes, in "Being Popular", after being excluded from the Murdoch party at Labour's conference. "A rejection like this can puncture our self-possession."

People who have suffered similar episodes of negative invitation may feel that an absurd oversensitivity on this point makes Draper the ideal psychotherapist for them. As Draper says: "We are healers, not heroes" and: "There will be occasions when we are struggling with our own issues while trying to help our patients." But still, given the explosion of demand for psychotherapy and the haphazard regulation of its 50,000 practitioners, it seems reasonable to ask how often and to what extent a healer is allowed to be reprehensible.

We may accept a therapist who is, from time to time, bullying, boastful, greedy, shallow, self-obsessed, vulgar, unprincipled, childish and hypocritical. But should it be possible for Draper to work in mental health now he is known to endorse the use of mental health rumours as not merely an acceptable political weapon, but "absolutely totally brilliant, Damian"?

The British Association for Counselling and Psychotherapy, BACP, of which Draper is a member, will respond to complaints that he has contravened its ethics. Although (perhaps because it is thought to be confined to novels by Wilkie Collins) there does not seem to be an explicit prohibition against false allegations of madness, a list of desired "personal moral qualities" includes those of empathy and humility. But in the event that the BACP did exclude Draper, it would be possible for him to continue to practise as a psychotherapist or counsellor, since neither term is protected. Anyone in need of podiatry, on the other hand, can be reassured that Draper will never be allowed to mess with their feet.

An end to his BACP membership would require only minimal adjustments to a professional website in which Draper is opaque about his therapeutic approach. "The kind of therapy I practise rests on the interaction between two people as it unfolds in the therapy room," he says, mysteriously. "I urge you to take that difficult first step and bring whatever is on your mind directly to me."

Well, Derek, what's on my mind is this: does anyone with a problem deserve to have you, after your second public disgrace, as their psychotherapist? Is there no presumption, in your line of therapy, of an enhanced degree of self-knowledge on the part of the healer? I notice that even though you have apologised to Labour supporters for "juvenile" emails, presumably written by your inner child, there has been, as yet, no similar courtesy to fellow practitioners of your day job.

Admittedly, to listen to some of his colleagues, the inherent unpredictability of an hour with Draper would be part of the attraction of a therapeutic process that lies beyond definition, let alone questions of qualifications, conduct or humdrum notions of "feeling better". A government project to bring all psychotherapists and counsellors under statutory regulation has recently inspired an argument about the nature of talking treatments that is as revealing as it is bitter, even by the impressive attritional standards of the psychotherapeutic community.

Negotiations between psychotherapists and their designated regulator, the Health Professions Council, had no sooner begun last year than anti-regulator Denis Postle compared participating clinicians to Nazi collaborators in Vichy France. A pained Mark Seale, chief executive of HPC, said he did not expect a spokesman claiming to represent "a caring profession" to resort to "offensive and demeaning propaganda". The therapist retorted that "caring profession" had nothing to do with it. "My occupation is personal and professional development, with a special emphasis on group process."

Anyway, so far as an outsider can understand it, the camps are currently divided into 1) an alliance of psychotherapists who accept, grudgingly, the argument for protecting vulnerable patients; and 2) an alliance of psychotherapists who believe it is not in the nature of talking treatments to be susceptible to state-imposed regulation. "Psychotherapy and counselling," says the anti-alliance, "though usually helpful, are inherently 'risky'; they cannot be made to conform to safety-first culture."

It seems unlikely, then, that any of Draper's clients will be able to get their money back on the grounds of proven non-empathy, even if it was Mrs George Osborne and not them he had hoped to pass off as loopy. But - see the sun bursting through - his untouchability as a psychotherapist provides one of the clearest arguments possible for the proper regulation of talking treatments. And that is absolutely totally brilliant, Derek.