By Lin Noueihed

BEIRUT, Aug 10 (Reuters) The thuds of distant explosions echo over Beirut at dusk. Shopkeepers lock up, people gaze at the sky, cars speed up and pedestrians hurry for home.

''Come on darling, I can't take this, I can't cope,'' says a tearful woman dragging a toddler who mimics the sound of the Israeli air strike -- ''bam, bam, bam''.

Israel's 29-day-old war with Hizbollah guerrillas is taking its toll on already frayed Lebanese nerves.

Some have seen loved ones killed or homes destroyed. Others may be less close to the violence but jump at every blast and weep at bloody news footage. Many Lebanese are still trying to forget the horrors of the country's 1975-1990 civil war.

''In Lebanon, many people have been through war before and for them these events can trigger a quick relapse,'' said Marwan Gharzeddine, a Lebanese psychologist.

''If people were traumatised before then the stress does not need to build up, they go straight into panic or flight.'' Up to 200,000 people fled Lebanon when the latest conflict erupted. Even those too young to recall the civil war can have trouble coping.

Alia Soufan, a 20-year-old interior design student, often crouches in the corner, her hands over her ears, when the sound of an Israeli air strike reverberates through her Beirut flat.

''The first week I couldn't sleep unless the house was full of people. Every time I heard a strike I would just lose my nerve and cry or scream,'' said Soufan, who grew up in Africa and had never heard bombs before.

''My mother bought me a herbal remedy which I try to convince myself is going to calm my nerves.'' (PASS THE PILLS) Lebanese are turning to tranquillisers, sleeping pills and anti-depressants.

''Demand in general is up 30 to 40 per cent. We get about 10 people a day asking for these drugs without prescription but we turn them away,'' said Hoda Zantout at Beirut's Mehio Pharmacy.

''Some people really need medication, especially refugees. They come and tell you their homes have been hit and they left their prescriptions in the south. They have a lot of problems.'' Relief groups helping some 900,000 people displaced by Israeli attacks have concentrated on providing food, water and sanitation but are also beginning to look at psycho-social problems.

UNICEF, the United Nations children's agency, said yesterday it was trying to help displaced children cope with memories that may prompt them to wet their beds, cry at the sound of bombing and cling fearfully to their parents.

Doctors say the full effects of the war on the mental health of the Lebanese will only become obvious once it is over.

''Open any woman's purse during war and you will find tranquillisers. People recommend brands to each other. These can help in the short run but they are highly addictive and people who take them don't know what they are doing,'' Gharzeddine said.

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