Behaviour change

Facts

Many teenagers will show a change in behaviour at times associated with changes in home/school circumstances, adolescent development and ill health. Most changes in behaviour will not be caused by brain tumour.
Most changes in behaviour will not be persistent (i.e. occur on most days over a period of time) or pervasive (i.e. occurring in multiple environments e.g. home/school/holiday).
Most teenagers with a change in behaviour associated with a brain tumour will have other symptoms/signs – these should be looked for carefully.

Behaviour changes caused by a brain tumour:

are expected to occur persistently – routinely over days or weeks
are expected to occur pervasively – across all settings, such as at home, at school, at play, on outings or visits away. Teenagers with a persistent and pervasive behaviour change should be seen by a doctor

Brain tumours in teenagers frequently cause lethargy (severe tiredness and reduced energy levels), a change in mood, dis-inhibition or withdrawal. Lethargy may cause:

significant reduction in activity levels, and spending more time resting
lack of enthusiasm or desire to participate in activities that they had previously enjoyed, across different activities and in different environments
becoming tired or fatigued more readily or quickly than they used to
falling behind or progressing more slowly at school, college or work
persistently – occurring routinely over days or weeks
pervasively – across all settings, such as at home, at school, at play, on outings or visits away

If you're a teenager and you're concerned about your symptoms, it's best to get them checked out by your GP.

If you're a parent or carer of a teenager and you're concerned about their symptoms, explain that you think they should go to the GP and offer to make them an appointment. Bear in mind that, depending on their age and circumstances, they may choose to go to the GP on their own, although many appreciate having a parent or carer with them whatever their age.