d state was induced. However, each group was able to rate the tasks accurately regarding short or long amounts of time needed to complete the task. Thus it was only the subjective or feeling aspect related to the passage of time that was affected by the depressed state, rather than the actual passage of time. While this study provided some insight into the relationship between depression and perceptions of time passage, limitations included a small sample size and the use of a nonclinical population only. Thus actual effects of depression on time passage perceptions was not measured; instead effects of a depressed state were measured. A study is needed to replicate aspects of this study, comparing a clinical and nonclinical population.
Other studies of psychological states and time perceptions include effects of attention deficit hyperactivity disorder on perceptions of the passage of time. Barkley, Murphy, and Bush (2001) studied time perception in young adults with attention deficit hyperactivity disorder (ADHD). For this study 104 adults with ADHD were compared with 64 controls. Each subject participated in a time estimation task and completed a battery of psychological tests. The time estimation task included an examiner using an electronic stopwatch, starting and ending, while participants guessed intervals. Findings showed that ADHD participants reported larger time estimations compared to controls, particularly at long intervals. After controlling for IQ, these findings were nonsignificant. Thus it appears that IQ was a mediating factor in the perception of time passage. While this study did not measure effects of depression, it did include a clinical and nonclinical population, offering support for this methodology.
Roxburgh (2004) presented findings of a recent study of time and depression that focused on the effects of subjective time pressure on depression. A telephone survey was used to assess 790 pa...