Mental Capacity Case

RB Greenwich v CDM

Cohen J


This case concerned a 63 year old woman with a diagnosis of personality disorder and poorly controlled diabetes.[1]            While there was a dispute between the applicant local authority and the Official Solicitor (on behalf of CDM) relating to her capacity to determine her residence and manage her property and affairs, both agreed that she did have capacity to make decisions about her care and treatment or, in the alternative, had "fluctuating capacity" so to do.

CDM lived alone with her pets following the death of her husband in 2014. The couple had had a number of dogs and cats which CDM referred to as her "babies": concern was raised after CDM allowed the condition of both herself and her home to deteriorate. CDM had a history of poorly controlled diabetes as a result of which she sustained an amputation of the right toe and subsequently in May 2017, her lower right leg. Shortly prior to the amputation of her lower right leg, CDM fell and sustained a fracture to her hip.

Subsequent to the amputation, CDM was discharged home, but refused to engage with orthodox rehabilitation methods – she insisted on mobilising with an upside-down broom, rather than a walking stick or zimmer frame, and continued to sleep on the sofa rather than in the bedroom she had shared with her late husband. After a short period at home, she was discovered by the ambulance service sat in vomit and faeces and was taken first to hospital, and then to a nursing home. Throughout the proceedings that followed, CDM remained adamant that she wished to return home to her "babies". Cohen J noted that she remained "fiercely independent, articulate and determined" and felt "erased" by her treatment.

The parties instructed an independent psychiatrist, Dr Series, to provide a report on CDM's capacity, in which he concluded that there would be an "inevitable variation" in her mental state due to fluctuations in her blood glucose, both as a result of her poorly controlled diabetes, and in the context of a diagnosed personality disorder. Having concluded that the CDM had fluctuating capacity to determine where she should live, Dr Series revised this opinion in the course of his oral evidence, ultimately concluding that she lacked the requisite capacity.

Cohen J resisted the submissions of the Official Solicitor to the effect that questions of capacity have to be made prospectively in order that professionals responsible for P's care are able to make decisions in their best interests without daily capacity assessments. Rather, he held that

50 […] Paragraph 4.4 of the Code of Practice says that an assessment of a person's capacity must be based on their ability to make a specific decision at the time it needs to be made and not their ability to make decisions in general.

  1. I accept that in some examples, for instance, the capacity to consent to sexual relations the capacity albeit fluctuating will be one that will either be present or not present. But management of her diabetes is a different matter. It covers a wide range of different situations which may arise frequently or infrequently. The treatment required may be of very different natures. I cannot see that this particular form of fluctuating capacity can properly be managed other than by a decision being taken at the time that the issue arises.
Cohen J then extrapolated from this position to hold that, given that CDM's personality was regarded by Dr Series as aggravating her diabetes as it led to poor diabetic control which in turn led to the making of unwise decisions about her treatment and an inability to cooperate with professionals, "when making appropriate decisions she has capacity but when making manifestly inappropriate decisions she lacks capacity."


This decision goes to show precisely how difficult it is for the court to deal with fluctuating capacity.[2]  The approach taken by Cohen J was faithful to the time-specific nature of capacity but is more than a little problematic to apply in practice.  In particular, it is difficult to see  how professionals are left with an appropriate touchstone to decide when CDM is, and is not, making capacitous decisions about her diabetes medication.

Cohen J's decision is also one that (albeit for perhaps understandable reasons) comes very close to recasting the capacity test as an outcome-based test in a way that was expressly rejected by the Law Commission in its work leading to the MCA 2005.  If the case goes further on appeal, it will be interesting to see whether the Court of Appeal sees this as a problem with the Act itself when it comes to fluctuating capacity, or a problem with the way that it was applied on the facts of this particular case.

[1] Katie being involved in this case, she has not contributed to this report.

[2] Although there is at least one case we know of where the judge has made 'contingent' declarations as to the circumstances under which P would lack capacity.