the response is likely to be a deafening silence, from those most likely encountered, a Psychological Wellbeing Practitioner (PWP) or a GP. Alternately, they may reply ‘it’s complex’, leaving you bemused or patronised with a reply of ‘we don’t know until you try’. But the cancer sufferer and those close, would not tolerate being fobbed off about the likely success rate of a proposed oncology treatment. Further they would deem it necessary for a face to face consultation, with a Consultant, for this question to be satisfactorily answered.
Contrast this with the likely scenario in mental health, following a self-referral you would undergo a 20-30 minute telephone assessment by a Psychological Wellbeing Practitioner (PWP) [ from the Improving Access to Psychological Therapies (IAPT) programme] the most junior member of staff. Unfortunately their training totally precludes their being able to answer this question. The problem is that the PWP simply does not know the answer. His/her stock in trade is low intensity interventions such as guided self-help or computer assisted therapy, delivered in six or less sessions. The PWP’s training courses inform them that such interventions outperform usual treatment. More than that they do not know. Their ambition is usually to become a high intensity therapist delivering psychological therapy, over a much greater number of sessions.
The PWPs are unaware that the success of Cognitive Behaviour Therapy (CBT) in low intensity outcome studies has been gauged solely in terms of a metric called effect size. The (within subject) effect size is calculated by subtracting the post treatment mean of a sample from the pre treatment mean and dividing by the spread of the results (the pooled standard deviation). [Alternately if there has been a comparison group in the CBT studies the means that are subtracted, are the post treatment means of each group, again divided by the standard deviation, to yield a between subjects effect size]. Assuming that a between subjects effect size has been calculated all this tells one is the size of the difference between the two groups, it does not tell you whether everyone improved a little, or some greatly improved whilst some did very poorly. Thus the effect size gives no information that can be passed onto a client that would give them a guide as to the likelihood of their recovery after low intensity intervention.
By contrast the psychological therapies to be delivered in high intensity IAPT, are supposed to be based on protocols approved by the National Institute of Clinical excellence. At first sight this is good news because many of these studies indicate the proportion of people who lost their diagnostic status as a result of psychological treatment i.e these studies were concerned with an end point and not just with whether there had been a response to treatment as indicated on some psychometric test. But IAPT has only ever relied entirely on psychometric test results. This exclusive focus on response by IAPT however lacks any validity because it is not known what the person was suffering from in the first place!. IAPT eskews diagnosis, there is a consistency in this in that because they don’t do end points, they don’t do beginning points i.e they do not establish what the person is suffering from in the first place. It is not possible to substitute measures of response for categorical endpoints, the latter are determined independently using standardised diagnostic interviews. Matters are compounded further because IAPT uses no measure of treatment fidelity, thus it is totally unknown whether IAPT actually delivers an evidence supported treatment.
Dr Mike Scott