Imagine helping victims deal with the trauma of a terrorist attack. Imagine too encouraging a football team to think positively and achieve the results which help them win leagues or avoid relegation.For psychologists, these are just two wildly different ways in which the various disciplines of their specialist subject can make a massive difference to the lives of others. Little wonder, then, that all branches of psychology prove to be such popular subjects among university students.

Undergraduate study of psychology is, in fact, one of the fastest growing degrees in the UK and it is therefore unsurprising that postgraduate courses are also heavily subscribed, whether students are aiming for a Masters degree or going on to complete a PhD.

In the UK, 123 universities offer a total of 655 masters degrees in psychology and - according to the British Psychological Society - approximately 25 per cent of graduates in the subject go on to further study. For those wanting to become a chartered psychologist, a postgraduate qualification is vital and, assuming that you have 2:1 or higher grade from a Society-accredited undergraduate degree, then postgraduate study in the subject is open to you.

Among those teaching the subject is Professor Patrick J O'Donnell who is passionate about helping students to understand how best to apply scientific method to explain human behaviour, cognition, and emotion. He's taught introductory courses in the field for 40 years is the current deputy head of Glasgow University's School of psychology.

"Postgraduate courses tend to cover a speciality, for example brain imaging, forensic psychology, educational psychology, clinical psychology, child psychology or occupational psychology," says O'Donnell. "These qualifications are often tied to professional training and accreditation but the specialisation may be academic and can cover any of the core areas of the discipline or be linked to interfacing disciplines such as economics, politics, social research, neural science, and engineering or computing."

Those who study psychology at postgraduate level are called on to formulate theories and test hypotheses by using self-reports, observations and behavioural measures including brain activity measurement. They analyse and report their findings using a range of statistical techniques.

One thing to consider is the area in which you wish to specialise. Psychology is a varied subject and students can work in many diverse areas.

Educational psychology, for example, would appeal to students looking to apply psychological theories, research and techniques to help children, in conjunction with their teachers and families, overcome learning difficulties and emotional problems.

Forensic psychology is primarily for those interested in the rehabilitation of offenders while clinical psychology is ideal for those who want to work in the field of mental health, taking in assisting people with eating disorders or substance abuse, working with those who have learning disabilities or those who've suffered trauma.

A growing field of study is sports psychology, which helps sportsmen and women improve their concentration or deter them from retaliating against provocation. Football club managers such as West Ham's Sam Allardyce surround themselves with sports psychologists.

Indeed, Carole Seheult, chartered as both a clinical and a sport and exercise psychologist, said the subject was vital in modern football. She has worked with professional athletes for more than 20 years and says psychology has a hugely positive effect on sporting success.

The expectations made of students depends on the course they follow and whether there are applied aspects to the course, such as cognitive and psychobiology elements. Arts courses have more emphasis on human aspects, while science courses will be more quantitative and scientific in content.

An added bonus of study in and around the subject is that the tools of the trade lend themselves very easily to other areas.

"It's clear that psychology has many applications," says Dr Ian Walker from the Department of psychology at the University of Bath. "The level of research and analysis, the level of writing skill needed and the numeracy required will equip students for a broad range of careers. You tend to find that postgraduate psychology students are good at everything and are very much in demand by employers."

Tom Davie, the deputy head of the Careers, Employability and Enterprise Centre at Durham University, agrees.

"The courses contain a range of module content which would be valuable in any career," he says. "Development or social psychology would have useful transferable knowledge for people considering future careers in social or youth work.

"Research design and methods would be invaluable for people wanting to enter postgraduate study, academic careers or roles which required logical and analytical skills such as human resource management, logistics, strategic roles in the public sector or business careers."

Indeed, psychology students will leave their courses equipped for a variety of roles including general management, human resource management, not to mention research roles both within psychology and in computing science, medicine and engineering. "Psychological researchers interface with disciplines like engineering and software design and are crucial to the development of usable computer interfaces, social robots and medical interventions based on behavioural methods," says O'Donnell.

In order to gain entry to a psychology course, it's essential to have a psychology degree which confers Graduate Basis for Chartered Membership (GBC) of the British Psychological Society (BPS). It would also be essential to have some relevant work experience related to the future occupation a student was considering.

But, when complete, according to Mr Davie, more than 60 per cent of jobs are open to psychology postgraduate students. He says the skills students that learn from a degree - plus the transferable skills from student life, voluntary and part-time work - contribute to success in the job market.

So, when making your mind up about postgraduate study, it's clear to see why psychology is so appealing to students.