The Proposed NICE (Mis)Guidance on the Treatment of Depression

excludes consideration of assessment https://www.nice.org.uk/guidance/indevelopment/gid-cgwave0725/consultation/html-content-3, in it’s’ update of the 2009 Guidance [CG90], despite advocating different pathways for ‘less’ and ‘more severe’ depression, advocating a cut-off of 16 on the PHQ-9.! De facto the authors rubber-stamp the widely held practice, reflected in the Improving Access to Psychological Therapies (IAPT) Service, of routing high scorers on a depression psychometric test (e.g PHQ-9 score 10 or greater) to treatment for this condition. But patients with a wide range of disorders including, panic disorder, PTSD, obsessive compulsive disorders and adjustment disorder have elevated depression scores. Nevertheless NICE signals a diversion along a depression pathway with one fork for ‘less severe’ and another for the ‘more severe’. Clinicians and clients are likely to be equally bemused by the ‘road signs’. The upshot is likely to be misguided treatment.

In assessing the outcome studies NICE do not take seriously the concept of minimally important difference (MID) i.e what change would a a patient see as the minimum requirement necessary for them to say treatment has made a real world difference. There is no evidence that they would regard a change of score on a psychometric test as conferring a real world difference. But they would recognise being back to their old self or best functioning and possibly no longer suffering from the disorder, so that loss of diagnostic status would be a reasonable proxy for a MID. However only a minority of studies furnish this data with the use of blind assessors. Inferences can therefore only be properly drawn from this sub-population of studies, which exclude the low intensity studies.

Under the proposed Guidance client’s preferences are paramount.  If the client is judged as having ‘less severe’  depression and volunteers no treatment preference, they are to be taken through  a menu of options in a set order starting with first group cognitive behavioural therapy, second group behaviour activation, third individual CBT and on to the 11th option short-term psychodynamic therapy.  For ‘more severe’ depression top of the league is individual CBT plus antidepressants, in 2nd place individual CBT, and in 3rd place individual behavioural activation and in last and 10th place is group excercise. The ‘more severe’ route is more labour intensive and there is likely to be congestion as approximately half those entering IAPT have mean scores of 15 or more on the PHQ-9 [Saunders et al (2020) https://doi.org/10.1017/S1754470X20000173]. Unwittingly the Guidance spells the end of low intensity interventions because none of the top of the league options are low intensity! But 70% of clients entering the IAPT service are given a low intensity intervention first. However there is nothing to prevent a Service Provider declaring that ‘unfortunately none of the top of the league options are currently available’ and recourse has to be made to options in danger of relegation. So much for NICE Compliance and patient choice. 

The NICE guidance assumes that psychometric test results speak for themselves but they are only meaningful when described in context. To my knowledge there is no study of the reliability of the PHQ-9 in UK routine mental health services compared to a ‘gold standard’ diagnostic interview. Rather data on the PHQ-9 has been extrapolated from from US studies of psychiatric outpatients, in a population with a high prevalence of depression, but not using a ‘gold standard’ diagnostic interview [The Prime MD was used instead, with insufficient distinction between this interview and the questions on the PHQ-9]. It is the author’s experience that in the UK the PHQ-9 gives a large number of false positives compared to a reliable diagnostic interview, such as the SCID.

NICE has a ‘blind spot’ about context. In its’ analysis of outcome studies it lumps together ‘depression studies’ that were wholly reliant on self-report measures with those that included the results of a diagnostic interview as an outcome measure. Outcome is assessed in terms of statistical differences between either different modes of service delivery e.g stepped v non-stepped or between different treatments e.g CBT v waiting list. There was no attempt to try and discern what proportion of clients in each arm of a study would have regarded themselves as back to their normal selves or best functioning post treatment [ or in lieu of this, lost their diagnostic status] and the duration of those gains. Rather than patients being asked to cite preferences over treatments they largely have no knowledge of, they would be very interested as to the likelihood of treatment making a real world difference to their lives.

NICE’s failure to look at context is highlighted in the top league place it gives to group CBT for less severe depression. No mention that in our study [Scott and Stradling (1990)https://doi.org/10.1017/S014134730001795X ] of individual and group CBT for depression in Toxteth, Liverpool the invitation to group CBT went down like a ‘lead balloon’ and we had to change the protocol to include up to 3 individual sessions in the ‘group’ arm. Entry was determined by independent diagnostic interview, but mean entry Beck Depression scores were around 27, so the population was likely ‘more severe’ in NICE terms. NICE also fails to critically appraise the Group Behavioural Activation studies, having previously called for BA studies to include observer rated assessments. They may have also added the need for credible attention control comparisons. NICE is content with statistical sweeps at large data sets rather trying to discern what is happening at the coal face.

NICE puts group interventions as top of the league for less severe depression, but ignores the context of the pandemic, realistically how possible will it be two get 2 therapists together with 8 clients for 90 minutes a week for 8 weeks, all face to face. The logistics and effectiveness of conducting it online is a venture into the unknown. NICE appears to operate without contextualisation of findings.

NICE are open to commentary on the proposals upto January 12th 2022. Will send the above, but I don’t think I will receive a return Christmas Card any time soon. Nevertheless a Happy Christmas to everyone.

 

Dr Mike Scott