so that the causal links with it cannot be denied," the doctor said in the opinion.

The 2005 case involved a 14-year-old male junior high school student in Aichi Prefecture who jumped to his death from an apartment.

In a report on the case by Chugai Pharmaceutical, the doctor who was in charge of the teenager said: "What I can say is that the use (of Tamiflu) might be linked. It is unclear whether the student's fall was caused by side effects (of the drug)."

In January 2006, the health ministry said that after hearing the opinions of numerous experts, it was "negative" to possible causal relationships between Tamiflu and abnormal behavior.