What right has the Improving Access to Psychological Therapies (IAPT) Service to routinely label each client with a diagnostic code (ICD of the International Classification of Disorders, World Health Organisation) when the Organisation’s Manual states that it does not do diagnosis. Fearful of litigation, it states that its diagnoses should not be used for medico-legal purposes, but as the code is the determinant of treatment, IAPT should be in the dock!
The Improving Access to Psychological Therapies (IAPT) service screens clients for treatment using the PHQ-9 but a study published in the British Medical Journal by Brooke Levis et al last year http://dx.doi.org/10.1136/bmj.l1476 indicates that half the deemed depression cases have been incorrectly diagnosed.
In high quality randomised controlled trials of the treatment for depression all clients admitted have been diagnosed as having depression according to a ‘gold standard’ diagnostic interview such as the SCID. The recovery rate in the rcts is 50%. But IAPT claims that it approaches the recovery rate of rcts. This is preposterous! Consider 100 IAPT cases which score above the PHQ-9 cut off of greater or equal to 10. One half of them i.e 50 will not actually have depression and therefore cannot recover from the disorder. Of the other half, 50 cases, if the IAPT clinicians were as good as in the rcts 25 would recover. Thus the maximum possible recovery rate for depression in IAPT is 25% and this is assuming its clinicians are as good as the highly trained clinicians in rcts. More plausibly the recovery rate for depression in IAPT is the 14.9% I found in my independent study of IAPT, http://DOI: 10.1177/1359105318755264 https://doi.org/10.1177/135910531875 using the SCID.
In primary care 22% of patients score over 10 on the PHQ9, so what are the treatment implications for the likely 3 out of 4 IAPT clients who score below 10? For these the PHQ-9 offers no direction.
But IAPT has its’ own answer, IAPT Manual, p 24 (2019), a) come up with a problem descriptor then choose an ICD 10 that that ‘matches’ the descriptor and then b) a NICE treatment that matches the ICD 10 code. Consider an IAPT client who reports that they are feeling emotionally numb at work, detached from others and fatigued after little exercise. The therapist could plump for either depression, burnout, chronic fatigue syndrome or the effects of COVID-19, with no guidance as the appropriate label!
Using IAPT system Delgadillo et al (2020) http://dx.doi.org/10.1037/ccp0000507 classified over 40% of clients as having ‘Affective Disorder’ and over 20% as having a ‘mixed disorder’. But there are no randomised controlled trials for ‘affective disorder’ or ‘mixed’, so that for 60% of IAPT’s clients there cannot be an appeal to an evidence based treatment (i.e one based on a randomised controlled trial). Considering again a sample of 100 IAPT clients who score less than 10 on the PHQ9 60 of them will have been labelled with a disorder for which there can be no evidence based treatment, this leaves 40 clients who in principle could be treated with an evidence based treatment. Again assuming that for this population of 40 that allegedly covered GAD (10-12%), panic disorder (4-6%), social anxiety disorder (4-6%), specific phobia (0.5-1.0%), OCD (4-5%), PTSD (6-8%) and other (2-3%) there was an overall recovery rate of 50% only 20% of the allegedly ‘non-depressed’ clients would recover. This 20% would have to regarded as an upper limit because it assumes the IAPT therapist would be as skilled as the highly trained therapists involved in the rcts for anxiety disorders. A more realistic estimate of recovery for the IAPT ‘anxious clients’ would be the 14.2% found in my study of IAPT clients http://DOI: 10.1177/1359105318755264 https://doi.org/10.1177/135910531875
The other metric employed by IAPT is the GAD-7, a measure of the severity of anxiety, but as according to IAPT it has only been relevant to one in 10 of its service users, any effect of the treatment of this disorder will only effect the above picture minimally. Assuming a 50% recovery the effect will be even less and less still when one compares the training of therapists in GAD acts with the training of the routine IAPT therapist.
IAPTS sole reliance on psychometric tests and fudge has backfired badly, but it is the client who suffers most, with therapists suffering from the recoil.
Dr Mike Scott