Preschoolers below the age of six are not immune to stress and its effects.

Dr Ken Ung, a psychiatrist and senior consultant at Adam Road Medical Centre, said a common stressful situation for children below the age of six is when they start preschool.

Separation anxiety

Such stress typically stems from separation anxiety - this can happen when the child is separated from a loved one or caregiver to whom he or she has an emotional attachment.

Dr Ung, who has a special interest in child and adolescent psychiatry, psychotherapy and forensic psychiatry, said that children at that age are pre-wired to be attached to a caregiver for their survival. So when there is separation, they become anxious.

'It is a fairly universal ritual for many children to endure this stress when they start preschool,' he said. 'However, as their caregivers help them to see that the separation is transient, that nothing has happened to their relationship and that their caregivers continue to be present after the absence, the stress slowly reduces as the fear or threat associated with the separation recedes.'

Aside from separation anxiety, being in a new environment itself can be another stressor when starting preschool.

Dr Ung said that while some children adapt well to new situations, others are 'slow to warm up' and struggle to adapt initially.

Then, there are the children who are by nature 'difficult' and who do not take well to change. This group is expected to do the worst with the change of starting preschool and though most will eventually adapt, they may take a lot longer.

Activity overload

Meanwhile, overloading a young child, who is trying to adapt to a new situation, with extracurricular activities can take its toll too.

'At preschool, enrichment classes are useful to help parents discover which of the many interests they should help their children cultivate.

'However, it is important that children are not loaded with too many enrichment classes, nor should they be made to persist in an activity in which they have no interest or aptitude to pursue,' said Dr Douglas Kong, a consultant psychiatrist at Mount Elizabeth Hospital.

Enrolling a child in too many programmes can overload his or her ability to handle information, thus stressing the child, he said.

It is also imperative that the activities are appropriate for the child's level of physical and psychological development.

Parental expectations

Dr Ung noted that stress often occurs when there is a mismatch between a child's abilities and the demands placed on him by his parents or the environment.

Mrs Jeanette Buckley, 35, the managing director and principal of Hess Education Centre, said that one issue in Singapore is the speed with which parents want their child to start reading and writing.

'Parents try to get their children to rote-memorise words,' she said. 'We have had plenty of children come to us to be assessed. Sure, they can recognise words, but they're not necessarily reading.

'The minute they come to a word they don't know, they become stressed and can't sound it out. In addition, there are children who learn to read but do not comprehend words.'

Their stress, from such demands placed on them, can be exacerbated if they sense they are not meeting their parents' expectations or if their parents seem unhappy.

'Pushing them too hard, especially when they perceive there is displeasure and when they feel that they are letting their parents down, can spark insecurity and lower their self-esteem,' said Dr Ung.

Dr Kong added: 'A young child's self-esteem depends on his parents' love and approval. The child will always strive to please them.'

Other possible stressors include a child's home environment. Parental arguments, separation and divorce can create anxiety because there is concern over the possible absence of one of the parental figures.

Stress symptoms

While acknowledging that stress is inevitable, Dr Ung said too much stress is not healthy for the mental health of young children.

'Children are developing physically and psychologically,' he said. 'If they start to learn that the environment is dangerous and threatening, that is the mindset they may grow up with. This may lead to their becoming prone to anxiety and depression when they are older.'

Dr Kong said that learning can also be compromised when the child is stressed and anxious.

As young children may not have developed the ability to verbally express their thoughts and feelings yet, stress is often signalled by overt behavioural changes.

These include crying, irritability and an increase in the level and frequency of temper tantrums and sleep difficulty.

Miss Jessie Ooh, a psychologist at the University Children's Medical Institute at National University Hospital, said signs to look out for are the physical effects of stress such as stomachaches. She added that the picking up of new habits such as thumb-sucking can be another indicator that a child is stressed.

Dr Ung said: 'Most parents have an idea of the basic temperament of their child. Under stress, there will be marked changes in their behaviour and this would normally alert a parent.'

If the stress is chronic and behavioural changes are ongoing, parents should seek help for their child.

'The best prevention method is for parents to understand their children well - their strengths and weaknesses - and to provide a good match between them and their environment.'