Depression is a mental state of low mood and aversion to activity. It affects more than 280 million people of all ages (about 3.5% of the global population). Depression affects a person's thoughts, behavior, feelings, and sense of well-being. Depressed people often experience loss of motivation or interest in, or reduced pleasure or joy from, experiences that would normally bring them pleasure or joy.
In the study of psychology, neuroticism has been considered a fundamental personality trait. In the Big Five approach to personality trait theory, individuals with high scores for neuroticism are more likely than average to be moody and to experience such feelings as anxiety, worry, fear, anger, frustration, envy, jealousy, pessimism, guilt, depressed mood, and loneliness. Such people are thought to respond worse to stressors and are more likely to interpret ordinary situations, such as minor frustrations, as appearing hopelessly difficult.
Feelings are subjective self-contained phenomenal experiences. According to the APA Dictionary of Psychology, a feeling is "a self-contained phenomenal experience"; and feelings are "subjective, evaluative, and independent of the sensations, thoughts, or images evoking them". The term feeling is closely related to, but not the same as, emotion. Feeling may for instance refer to the conscious subjective experience of emotions. The study of subjective experiences is called phenomenology.
In psychology, temperament broadly refers to consistent individual differences in behavior that are biologically based and are relatively independent of learning, system of values and attitudes. Some researchers point to association of temperament with formal dynamical features of behavior, such as energetic aspects, plasticity, sensitivity to specific reinforcers and emotionality. Temperament traits (such as neuroticism, sociability, impulsivity, etc.
Pessimism is a negative mental attitude in which an undesirable outcome is anticipated from a given situation. Pessimists tend to focus on the negatives of life in general. A common question asked to test for pessimism is "Is the glass half empty or half full?"; in this situation, a pessimist is said to see the glass as half empty, or in extreme cases completely empty, while an optimist is said to see the glass as half full. Throughout history, the pessimistic disposition has had effects on all major areas of thinking.
Dysthymia (dɪsˈθaɪmiə ), also known as persistent depressive disorder (PDD), is a mental and behavioral disorder, specifically a disorder primarily of mood, consisting of similar cognitive and physical problems as major depressive disorder, but with longer-lasting symptoms. The concept was used by Robert Spitzer as a replacement for the term "depressive personality" in the late 1970s. In the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV), dysthymia is a serious state of chronic depression, which persists for at least two years (one year for children and adolescents).
Affect, in psychology, refers to the underlying experience of feeling, emotion, attachment, or mood. The modern conception of affect developed in the 19th century with Wilhelm Wundt. The word comes from the German Gefühl, meaning "feeling". A number of experiments have been conducted in the study of social and psychological affective preferences (i.e., what people like or dislike). Specific research has been done on preferences, attitudes, impression formation, and decision-making.
Seasonal affective disorder (SAD) is a mood disorder subset in which people who typically have normal mental health throughout most of the year exhibit depressive symptoms at the same time each year. It is commonly, but not always, associated with the reductions in total daily sunlight hours that occur during the summer or winter. Common symptoms include sleeping too much, having little to no energy, and overeating. The condition in the summer can include heightened anxiety.
A mental state, or a mental property, is a state of mind of a person. Mental states comprise a diverse class, including perception, pain/pleasure experience, belief, desire, intention, emotion, and memory. There is controversy concerning the exact definition of the term. According to epistemic approaches, the essential mark of mental states is that their subject has privileged epistemic access while others can only infer their existence from outward signs.
The traits of extraversion (also spelled extroversion) and introversion are a central dimension in some human personality theories. The terms introversion and extraversion were introduced into psychology by Carl Jung, although both the popular understanding and current psychological usage vary. Extraversion tends to be manifested in outgoing, talkative, energetic behavior, whereas introversion is manifested in more reflective and reserved behavior.
