Is it 'normal' to think about pushing someone in front of a train or to fantasise about driving your car into oncoming traffic? The answer is yes, says Victoria University of Wellington researcher Dr Kirsty Fraser who graduated with a PhD in Psychology last week.
"It's common for people to occasionally have those kind of negative thoughts, but then most of us realise it's a bit ridiculous and move on," says Dr Fraser.
For some people, however, those negative thoughts may persist, leading to anxiety and depression.
"It's how we react to, and process, those negative intrusions that can make the difference between brushing them off and developing obsessive compulsive symptoms, such as severe anxiety and depression.
"For example, some people could be so anxious about those kind of thoughts that they go out of their way to avoid catching a train or driving."
Dr Fraser's thesis focused on two ways of processing negative thoughts—inflated responsibility (IR) and thought action fusion (TAF), and the way each relates to mental disorders.
"TAF is when you believe that thinking about an action is equivalent to actually carrying out that action, while IR is one of the driving forces behind obsessive compulsive disorder (OCD), where you believe you can prevent something happening by what you do or don't do.
"My research demonstrates that both types of beliefs play important roles in the development and maintenance of psychological symptoms related to anxiety, depression and OCD."
Dr Fraser's research also looked at how childhood experiences, critical events in one's life and religious beliefs could impact upon thoughts.
She surveyed more than 1,000 people and divided them into four groups: undergraduate students, so called 'normal' citizens, patients from an anxiety clinic and those with religious and atheist beliefs.
"Overall," she says, "my research provided strong support for existing theories about the role of cognitive processes in the maintenance of symptoms and distress."
When Kirsty arrived at Victoria in 2002, she began studying human resources. She took a psychology paper out of interest and "never left".
"The lecturer was John McDowall, who introduced me to how interesting the subject is. He ended up being my supervisor for my PhD."
For the past three years, Kirsty has combined doctoral study with teaching a second year psychology paper at Victoria, marking for another tertiary institution and being a full-time mother.
"Now I'm starting to think about other challenges, including possible research positions. I'd like to publish my PhD research and continue lecturing.