Patients Aware of Their PWS But Not Its Social Effects, Study Says

People with Prader-Willi syndrome (PWS) are aware of the disease, but not of its social consequences, a small single-site study has found.

These findings may have important clinical implications for care as “patients believe they are capable of independent living when they are actually not,” the researchers wrote.

The study, “Multidimensional evaluation of awareness in Prader-Willi syndrome,” was published in the Journal of Clinical Medicine by a team of researchers from Spain.

The team had recently adapted the Scale of Unawareness of Mental Disorder (SUMD) — originally designed to evaluate patients with schizophrenia — to PWS. The researchers wanted to gather information about patient insight, a broad term used to refer to a patient’s understanding and attitudes towards a disease. People with schizophrenia have shown a striking unawareness of illness and symptoms, leading to poor treatment compliance and greater risk of relapse.

In the study, the adapted interview was given to a group of 36 adults with PWS, 21 of them women, who attended the endocrinology department at Corporació Sanitària Parc Taulí de Sabadell, in Spain. Their ages ranged from 18 to 51 years.

Most patients (86.1%) lived with their families and more than one-third (36.1%) had studied in an adapted primary school. Half (50%) worked in an adapted occupational workshop.

The study also included 46 patients with schizophrenia-spectrum psychosis, which results in difficulties determining what is real and what is not real. Ten of these participants also had an intellectual disability other than PWS and were considered a separate group. Median age at disease onset was 21.3 years for those without an intellectual disability and 32.8 years for those with an intellectual disability.

One hallmark characteristic of PWS is increased appetite with continuous food foraging, which can lead to early childhood obesity. PWS patients had a higher BMI (or body mass index, a ratio of a person’s weight to height) than psychosis patients. Severe obesity — BMI equal to or greater than 40 — was more common among participants with PWS than among those with psychosis.

SUMD scores ranged from one to five, with higher scores indicating worse patient insight. PWS patients had good awareness about symptoms of the disease (median score of one), in particular excessive appetite and body weight. However, awareness of excessive food intake scored a median of three points.

Nearly 60% of PWS patients also had a current diagnosis of psychiatric disorder. About three-quarters (72%) were taking some kind of psychopharmacological medications, including anti-psychotics, benzodiazepines, and anti-depressants.

PWS patients had good awareness of the effect of psychopharmacological treatment (median score of two).

However, they were unaware of the social impact of the disease, as the median score was five, even though it “may affect their personal relationships and lead to behavioral problems in their daily life,” the researchers wrote.

Greater patient insight correlated with younger age and with a better score in the Global Assessment of Functioning scale — a mental health measure of how much a patient’s symptoms affect their daily life. Lacking awareness of PWS also correlated with current behavioral and emotional symptoms, assessed using the Strengths and Difficulties Questionnaire. However, it did not correlate with BMI.

Patient insight differed between PWS patients and those with psychosis. PWS patients had greater awareness of the symptoms of the disease than those with psychosis (with or without an intellectual disability).

Overall, greater patient insight may derive from the fact PWS patients “start with symptoms and behavioral problems in early childhood, and live most of their lives with parents, following adapted studies and work positions,” the researchers wrote.

In addition to the SUMD, the scientists designed two visual analog scales to score patient insight and disease severity. Scores ranged from zero to 10, with higher scores indicating greater awareness or disease severity. The median score for patient insight was five, and that for disease severity was eight.

The visual analog scale for patient insight correlated with age and score on the Global Assessment of Functioning scale. This simple scale “could be a good introduction to the insight dimension in future studies,” the team wrote.