Psychiatric Phenomenology of Mood Activation in Prader-Willi Syndrome 

Janice L. Forster, Linda M. Gourash

Pittsburgh Partnership: Specialists in Prader-Willi Syndrome, Pittsburgh, PA

PWS has been associated with an increased incidence of Bipolar Mood Disorder or cyclic psychosis. This association has been linked to the maternal uniparental disomy condition of PWS, although there are many case reports of individuals with the deletion condition who also display these severe psychiatric problems. Mood activation is an iatrogenic phenomenon associated with the use of medications. It can present with mood elevation, mood lability, irritability, impulsivity or increased goal directed behavior. In neurotypical populations, it has been associated with an underlying risk for bipolar disorder.   

The Pittsburgh 100 is a referred population of individuals with PWS who were admitted for inpatient evaluation and management of medical and behavioral crises who received psychiatric consultation as a part of their treatment. Despite the referral bias of this cohort, the demographics and genetics are comparable to the group of individuals with PWS in the general population. This clinical population was described by the nature of the presenting psychiatric/behavioral symptoms; family history of psychopathology; medication history; intellectual functioning; and mental status findings leading to psychiatric diagnosis.  All of the patients met criteria for Personality Change Secondary to a Medical Condition (PWS). Genetic information was available on one-half of the population; the other cases were diagnosed as PWS using clinical criteria.    

Among this referred population, patients who experienced mood activation were coded according to age, genotype, family history for psychiatric disturbance, hormone replacement status, and mood and/or psychotic symptoms on mental status examination. The temporal association of mood activation with medication exposure was noted. The signs and symptoms of mood activation were described.   

Results

Mood activation was predominately associated with exposure to SSRI medication.  Mood activation was not associated with age, family history, hormone replacement or genotype.  A history of mood activation did not automatically indicate a diagnosis of mood disorder.  Bipolar disorder with or without psychosis occurred in 50% of individuals with mood activation.  Other diagnoses occurring in the remaining 50% included anxiety disorder and disruptive behavior disorders.