Palace doctors believe Japan's Crown Princess Masako, who has spent the past eight months in seclusion fighting a stress-induced illness, will not likely resume her royal duties until sometime next year, officials said Monday.

The pronouncement by palace doctors treating the princess comes as her husband and Japan's royal heir, Crown Prince Naruhito, prepares to head Wednesday for Brunei, where he is to attend the gala wedding of the tiny sultanate's Crown Prince Al-Muhtadee Billah.

Once again, however, the 44-year-old Naruhito will be going alone.

The palace announced last week that Masako will not accompany him to the Brunei wedding, and on Monday an official said Masako's doctors believe she still needs a good deal more time to recover.

"It is the opinion of the royal doctors that it would be difficult for her to return to her duties this year," he said, demanding anonymity.

The official refused to comment further.

Palace officials have tried to play down Masako's illness, offering only the thinnest of explanations since the 40-year-old princess withdrew from the public eye late last December and urging the media to exercise "restraint" in its coverage.

But the princess' drawn-out battle with bouts of depression caused by the pressures of palace life has swelled into the biggest crisis faced by Japan's imperial family in decades.

Amid increasing calls for openness, the palace announced in July that Masako was suffering from an adaptive disorder and was being treated through counseling and drug therapy.

This weekend, Masako appeared in public briefly for the first time in four months, waving to cameramen from the back of a limousine taking her and Naruhito from their royal residence to the nearby Imperial Palace, where she met with her in-laws, Emperor Akihito and Empress Michiko.

Masako's disappearance has been a great disappointment to the Japanese public, who had hoped the affable and cosmopolitan princess might add a spark to Japan's famously staid and tradition-bound imperial family.

Educated at Harvard, Oxford and Japan's prestigious Tokyo University, Masako left a career in Japan's Foreign Ministry to marry Naruhito in 1993.

Source: Shenzhen Daily