Brief Report: Major Depressive Disorder with Psychotic Features in Williams Syndrome: A Case Series.

Valdes et al. (2018) looked at three adults who have Williams syndrome.

All three were later found to have major depressive disorder with psychotic features.

The team wrote short stories about each person to show how the mood disorder looked and what medicines helped.

Doctors first missed the depression in every case.

Mood symptoms looked like "just Williams personality" until clear hallucinations showed up.

Each adult needed different drug mixes, and two had bad side-effects before finding the right pill.

Farrant et al. (1998) saw the same problem in Prader-Willi syndrome. They found a large share of adults had mood-related psychosis, so the risk is not new.

Fyfe et al. (2007) followed PWS adults over years and saw the illness return. They warn that mood-stabilizers can backfire, a warning that matches the side-effects Francisca saw.

Ng et al. (2016) looked at anxiety, not psychosis, but they also found blunted body responses in anxious WS people. Together the papers say: check mood deeply, labels like "anxious personality" can hide real disorders.

If you serve adults with Williams syndrome, add a quick mood screen every six months. Ask about sleep, appetite, and voices no one else hears. When you see sudden clinginess or flat face, do not shrug it off as "typical WS." Share the case notes with the psychiatrist so they can pick medicines slowly and watch for side-effects. Early catch saves weeks of crisis.