A multidisciplinary approach to neuropsychiatric decompensation in Phelan–Mcdermid syndrome in an assessment and treatment unit: a case report

Purpose Phelan-McDermid syndrome (PMS) is a rare genetic disorder characterised by intellectual disability (ID) and is associated with autism spectrum disorder (ASD) and psychiatric comorbidities. This case report aims to describe the clinical course and management of a 29-year-old woman with PMS, ASD, moderate ID and bipolar affective disorder, demonstrating the challenges and the significance of multidisciplinary management in such complex cases. Design/methodology/approach This case report integrates clinical observations, pharmacological and behavioural interventions, genetic testing and validated outcome measures to track the individual’s presentation, treatment response and outcomes over an extended admission in an assessment and treatment unit in the UK. The authors have subsequently examined the findings from this case in the context of existing literature to elucidate emerging implications. Findings Genetic testing confirmed a diagnosis of PMS. The clinical course was characterised by recurrent neuropsychiatric decompensations, including mood disorder episodes and a suspected episode of neuroleptic malignant syndrome, which reflect pharmacological sensitivity. A personalised positive behaviour support plan and careful titration of psychotropics with management of physical health and related symptoms led to gradual recovery and improvement. The use of multiple outcome measures documented measurable improvements in mood, adaptive behaviour and challenging behaviours before discharge. Originality/value This is among the few detailed case reports emphasising on the neuropsychiatric complexity of PMS, the importance of awareness of its features including psychiatric manifestations and the value of person-centred multidisciplinary management in promoting recovery and quality of life.