If feelings of anxiety persist without an obvious trigger, literature describes them as possible features related to emotional or mental health. Public-health sources discuss mental health alongside physical health because both relate to overall well-being. Surveys indicate that a substantial proportion of people report a mental health condition at some point in life. Research on adolescents also examines trends in self-reported life satisfaction over time.
Mental health conditions are discussed in population studies for their associations with day-to-day functioning and, in some analyses, with physical health indicators. Many conditions can be long-lasting or recur across the lifespan. Reports note that a notable share of people describe emotional difficulties during the year. Adolescents may experience periods of low mood and heightened anxiety. Substance use and certain repetitive behaviors are covered in clinical literature within substance use and behavioral addiction frameworks.
Eating disorders are described in epidemiologic reports across ages and genders. They involve persistent patterns related to eating, body image, and weight, which can include restriction or episodes of overeating. Sources characterize these conditions as multifactorial, reflecting psychological, biological, and social influences.
Major depression is discussed internationally as a common mental health condition. Descriptions include prolonged low mood, reduced interest or pleasure, changes in sleep and appetite, and difficulties with concentration. In some presentations, thoughts of self-harm are reported in the literature. Symptom patterns can differ in duration and intensity among individuals.
Post-traumatic stress disorder (PTSD) is outlined as a condition that can follow exposure to traumatic events. Features documented in studies include intrusive memories, avoidance of reminders, changes in arousal or reactivity, and alterations in mood and cognition. The intensity and course of experiences vary widely, and symptom clusters are used in research to characterize the condition.
Bipolar disorder is described by mood episodes ranging from manic or hypomanic periods (elevated or irritable mood, increased energy, reduced need for sleep, rapid speech) to depressive periods (low mood, decreased energy, changes in sleep and appetite). Fluctuations in activity level, attention, and productivity are commonly discussed. Cognitive effects such as distractibility and memory difficulties are also noted during episodes.
Schizophrenia is summarized with positive symptoms (e.g., hallucinations, delusions, disorganized speech) and negative symptoms (e.g., reduced emotional expression, limited motivation, social withdrawal). Functional changes in daily life and social interaction are frequently mentioned. Prevalence estimates are comparatively lower than for many other mental health conditions.
Symptom profiles differ across individuals and contexts, influenced by personal history, temperament, and environment. Descriptions often focus on patterns in mood regulation, thought processes, perceptions, and behavior. Variability over time is common, and many accounts highlight interactions between psychological and social factors.
Across groups of mental health conditions, frequently described features include persistent low mood, difficulties with attention and concentration, confusion, excessive worry, feelings of guilt, reduced social engagement, fatigue, sleep disturbances (including insomnia), altered perceptions, and challenges managing daily tasks. Some individuals report substance use problems or gambling behaviors. Changes in sexual interest can also occur. Thoughts of self-harm are noted in clinical literature for certain conditions.
Learn more about mental health disorders at National Institute of Mental Health (NIMH).