We all know that regular attendance at school is hugely important.

Many factors adversely influence attendance, but a commonly overlooked one is mental health. 

Historically, children with particularly poor school attendance were considered to fall into two groups: school refusers - pupils whose parents struggled to get them to attend school; and truants - young people who skipped lessons in defiance of authority.  

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As a trainee, I was taught that emotional difficulties often explained school refusal while truancy was a sign of behavioural problems. This is incongruous with the population-based studies that show many young people have both types of mental health condition at the same time. 

Indeed, patterns of absenteeism are often mixed, while the variety of terms used to describe school attendance problems - which are often applied inconsistently - makes it difficult to compare studies. 

Researchers suggest using broader terms, such as “absenteeism” or “problematic absence”, which make no assumption about the underlying aetiology (causation) of the problem. Parents in the UK are similarly asking for a “holding code” while schools assess the reasons for poor attendance.

Long-term attendance issues

Depression, anxiety and internalising difficulties are consistently associated with poor school attendance across a variety of settings, cultures and age groups.

Depression, in particular, is strongly associated with unauthorised absence, while poor attendance is also associated with self-harm and suicidal ideation. So, long-term poor attendance or a sudden change should prompt school staff to consider whether the student has a mental health condition.

Poor mental health can impact on attendance in a variety of ways. Both anxiety and depression can have physical manifestations, which can be misinterpreted. Common examples include abdominal pain, diarrhoea, vomiting, headaches, feeling dizzy, difficulty breathing or urinary frequency.

All paediatricians work with children who have medically unexplained symptoms that can, on occasion, be severe enough to result in hospital admission.

Vicious circle

Both anxiety and depression disrupt sleep, while the agitation that is often part of these conditions is in itself exhausting. Concentration and motivation are also often impaired, and the resulting deteriorating ability to cope with academic work can itself trigger further anxious and depressive thoughts. 

While both types of emotional difficulty can relate to family factors, adverse experiences at school - particularly bullying or special educational needs and disability (SEND) - can precipitate anxiety or depression. 

Staff at school have more control over school-based factors and should actively seek and manage them. It is hugely distressing to parent a child with a significant mental health condition, and mental health conditions should have parity of esteem with other significant health conditions. 

We make accommodations for children who have broken limbs or diabetes, for example, so should not hesitate to do so for those with a mental health condition. 

The good news is that both anxiety and depression respond to treatment, so early referral is key. Waiting lists are an issue, of course, but the impact on education and development from untreated poor mental health is huge. 

Perhaps a code that suggests a mental health explanation for poor attendance might flag the need for resources. And perhaps that is something we should all get behind.

Tamsin Ford is a professor of child and adolescent psychiatry at the University of Cambridge. She tweets @Tamsin_J_Ford