Dr Nippat Karnjanathanalers, a Chulalongkorn Hospital psychiatrist, said doctors found men have more sexual problems than women because of a reduction in sex hormones, which could cause psychological problems like depression and stress.

Also a member of the Information Centre on Men's Health, he said reduced production of the male hormone testosterone makes men undergo physiological and psychological changes.

Changes vary from person to person, said Dr Nippat, as healthy men may have enough male hormones for normal sexual functioning, but quite often doctors find that reduced production of hormones brings sexual and other problems.

"A small reduction is not a problem, but if the drop is over 20 percent, there is a dampening of sexual desire," he said.

The symptoms commonly observed include hot flushes (irritable disposition and anxiety), muscle contractions (energy loss), high cholesterol levels, mood changes due to lack of initiative and memory lapses, and being overweight and an increase in body fat.

Dr Nippat said though the problem occurs among men from 40 years of age, not many visit doctors until they are over 50 years old.

He said a frequently occurring problem among men is erectile dysfunction; doctors have to determine whether it is due to low hormone levels or psychological effects.

"As a person gets older, psychological problems tend to increase," said Dr Nippat.

Psychological problems leading to reduced sexual performance often stem from depression and impotence, he said.

Men in the 40-60 year age group are prone to depression and stress, he said.

Dr Nippat pointed out that about 7% of people suffering from depression have reduced sexual performance.

In 20-25% of the cases, sexual functions are seriously affected, leading to impotency.

Furthermore, he said, they suffer from stress, which creates problems in relationships with the opposite sex.

"They are tired and lack energy. This causes the autonomic nervous system to be more active.

"The heart beats faster and muscles are tense, causing abnormal tiredness during sexual intercourse," he said.

Dr Nippat said such cases lead some men to exhibit inappropriate sexual responses such as premature or delayed ejaculation.

Others get afraid and do not dare to have sex anymore.

"Men are like women who won't accept the ageing process and try to delay getting older as much as possible," he said.

Since the establishment of the information centre, more men have sought medical counselling and information from the (635-1001) hotline, he said.

Currently, about 20 patients visit Chulalongkorn Hospital a month, said Dr Nippat, adding that most men do not want to see the doctor with their wives.

Urging women to pay more attention to the problem, he said if the wife is not too old and the husband has sexual problems, she may feel that the husband has another woman, which could lead to more family problems.

Dr Nippat said middle-aged men should maintain good health through exercise and healthy, low-fat food consumption if they want to reduce the chances of facing the problem.