Several terms have been used to describe similar concepts to mental health. In a study of the effect of pre-divorce parental relations on offspring outcomes, Amato (2001) and Amato, Loomis &
Booth (1995) used the concept of “psychological well-being”. The study of Amato (2001) comprised global happiness, life satisfaction, and self-esteem; and the study of Amato, Loomis & Booth (1995) comprised overall happiness and psychological distress. Hanson (1999) also used the term
“psychological well-being” to analyze the effect of parental conflict and divorce on children, where
“psychological well-being” comprised behavior problems, global quality of life, and self-esteem. Other common used measures of mental health are depression (Aseltine, 1996; Videon, 2002) and emotional problems (Chase-Lansdale, et al., 1995; Cherlin, Chase-Lansdale, & McRae, 1998).
In Taiwan, some scholars have measured mental health using the Taiwanese Educational Panel Study (TEPS). In a study exploring the relationship between educational achievement and adolescent mental health, Yang (2005) used 14 questions to measure mental health, including depression, insomnia, dizzy, loneliness, helplessness, suicidal ideation, etc. Huang & Lin (2010) used 15 questions of TEPS to develop a Mental Health Questionnaire to compare adolescent mental health between Taiwan and the United States, where the questionnaire included four subscales, measuring emotional symptoms, problematic behavior, attention/distraction, and peer relations. The most recent study using TEPS to measure mental health was the investigation of Wei (2008) exploring the influences on mental health.
Wei used 16 questions, similar to the study of Yang, to measure mental health, including depression, loneliness, helpless, insomnia, anger, etc.
Although the three domestic studies addressed above all use the term “mental health”, the
measurements employed more closely resemble measures of “mental disorder” or “mental illness”. That is, the measures employed focus only on the negative side of mental health, and do not sufficiently accurately measure overall mental health (Keyes, et al., 2010; Power, 2010; Tennant, et al., 2007). Keyes, Dhingra, and Simoe (2010) distinguished positive mental health from mental illness. Measurement of positive mental health include such measures as feeling cheerful, in good spirits, happy, calm or peaceful, satisfied, and full of life during the past 30 days. Keyes et al. (2010) compared changes of positive mental health and mental illness between 1995 and 2005 in adult population, and suggested that changes in mental health strongly predicted changes in mental illness. Westerhof and Keyes (2010) also
distinguished the concepts of mental illness and mental health, and indicated that mental illness (namely distressed) and mental health (namely happy) are related but distinct dimensions of a single concept.
Demonstrating the distinctiveness of these two concepts, age has more impact on mental illness, while gender and marital status have more impact on mental health.
Tennant, Joseph, and Stewart-Brown (2007) also proposed the importance of separately measuring negative and positive mental health. Positive psychology is another term similar to positive mental health, and is defined as “seeking to create more understanding of human happiness and optimal functioning”(Norrish & Vella-Brodrick, 2009), and being based on the assumption that “a fulfilling and happy life consists of more than an absence of mental dysfunction” (Keyes, 2005). Norrish and Vella-Brodrick (2009) considered positive measurements of mental health is particularly important for adolescents, because adolescents tend to have moderate or average mental health rather than good mental health. While most adolescents do not fall within the clinical range for mental illness, a large portion of adolescents exhibit mental health issues (namely lack of confidence, feelings of insecurity, etc.), creating a need for measurements that involve more than just mental illness.
The World Health Organization (2001) defines mental health as “a state of well-being in which every individual realizes their own potential, can cope with normal life stresses, can work productively
and fruitfully, and can make a contribution to their community”. The concept of mental health is broader than those of mental disorder or illness, and includes more dimensions than the mere absence of illness (Aneshensel & Phelan, 1999; WHO, 2001). Of course mental disorder or illness can decrease the likelihood of achieving good mental health, but measuring only mental disorder or illness does not provide a complete picture of mental health. Furthermore, recent studies demonstrate the need for positive measures of mental health (Keyes, et al., 2010; Norrish & Vella-Brodrick, 2009; Tennant, et al., 2007; Westerhof & Keyes, 2010). Johansson, Burnberg, and Eriksson (2007) investigated mental health from the perspective of adolescents, and the results obtained suggested that adolescents perceived mental health as an emotional experience incorporating both positive and negative aspects.
Therefore, this study uses both negative and positive measures of mental health. The negative measure is depressed mood, while the positive measure is happiness.
(1) Depressed mood
Adolescent depression can be classified using three levels (Petersen et al., 1993): depressed mood, depression syndrome, and clinical depression. Depressed mood is a common emotion that can occur at certain points in life and is typically linked to problems such as anxiety and social withdrawal. Depressed mood is typically measured through adolescents providing self-reports of their emotions, and is the single most powerful symptom for differentiating clinically referred and non-referred youth. Depression syndrome is a constellation of problematic behaviors and negative emotions, including social problems, thought problems, attention problems, etc. Depression syndrome is diagnosed based on reports of adolescents, parents, and school teachers.
Clinical depression is linked to a set of long-term emotion and behavior problems that impair functioning of affected adolescents. Clinical depression can be diagnosed using the categorization of mental disorders developed by the American Psychiatric Association or the World Health Organization.
In this study, because it adopts a sociological approach and the main focus is an adolescent population,
and because only self-reported data from adolescents is used, depressed mood is not an appropriate indicator of depression in this study. The measurement of depressed mood is calculated from four items from the student questionnaires, including “do not want to deal with others”, “feeling upset”, “wanting to yell or throw things”, and “feeling lonely”.
(2) Happiness
This study considers happiness an appropriate positive measure of mental health because it not only represents an important mental condition identified in numerous studies (Amato, 2001; Amato, et al., 1995; Westerhof & Keyes, 2010), but also has been found to reduce symptoms of psychopathology
(Diener, 2002), improve physical health (Dillon, 1995), improve coping ability (Fredrickson, 2002), increase self-control (Aspinwall, 1998), enhance relationships with others (Harker, 2001), increase opportunities for success (Lyubomirsky, 2005), and even contribute to longer lifespan (Diener, 2011).