Hugh Pickens writes: "A study of 8,000 people stalking members of the royal family from 1988 to 2003 shows that the majority of VIP stalkers suffer from serious psychotic illnesses. "We didn't expect such high rates of psychosis. It was very surprising to us," says Paul Mullen, a forensic psychiatrist at Monash University. Around 3000 of the files covered incidences that were judged to be pranks, or committed by people accidentally or while they were drunk but when Mullen's team examined a sample of the remaining 5000 people judged to be true stalkers about 80% had a serious psychotic illness, including schizophrenia, delusions and hallucinations,. The finding contrasts sharply with people who stalk non-famous people who tend to be rejected lovers, who while they may be depressed and socially inept, don't usually suffer psychosis. Researchers are currently investigating ways to identify which stalkers are likely to pose a threat. "[Stalkers] who are fixated on a cause, and have a highly personalized quest for 'justice', often delusional in nature, are the ones most likely to breach security, and to be carrying weapons," says David James, a forensic psychiatrist at the North London Forensic Service."