A new study examined how people’s mental health and well-being varies by time of day, day of the week, and season. They found people generally have the best mood in the morning and the lowest point at midnight. Seasonally, people tend to feel lowest in winter and best in summer.

The researchers looked at several measures of well-being, including mental health (symptoms of depression and/or anxiety), happiness, life satisfaction, sense of life being worthwhile, and loneliness (social well-being). More than 49,000 people participated, providing nearly a million survey responses over two years.

The study was conducted by researchers at University College London and published in the journal BMJ Mental Health. The study found that measures of mental health and well-being varied across time of the day, with people generally waking up feeling better and feeling worst around midnight. The authors suggest these daily variations “might be explained by circadian rhythms in physiological processes. For example, cortisol peaks shortly after waking and reaches its lowest levels around bedtime.” They also observed more variation in daily well-being on the weekends than during the week.

The impact of day of the week on well-being was less clear-cut. For example, depressive symptoms were higher on Wednesdays and Thursdays; happiness, life satisfaction, and worthwhile were all slightly higher on Mondays and Fridays; and happiness was higher on Tuesdays. In addition, there was more variation in daily mental health and wellbeing during weekends than during the week. For example, happiness and life satisfaction peaked first thing in the morning only during the weekend. These fluctuations may be associated with more work-related stress during the week and anticipation of more social and leisure activities on the weekend, the authors note.

Generally, things do indeed seem better in the morning.

Seasonal patterns were clearer with the best well-being in the summer and lowest in the winter. Depressive and anxiety symptoms were highest in the winter and levels of happiness, life satisfaction and sense of whether life being worthwhile were lower in winter compared to other seasons. The seasonal findings are in line with previous evidence for increased mental health concerns, including seasonal affective disorder for some, in the winter. The authors note, however, that the daily variations in the measures did not differ by season.

The measure of loneliness was the exception to these patterns.It varied the least across time of day, day of week and season. This is in line with previous research findings that feelings of loneliness are stable over extended time.

The authors note several possible implications of the research, including the need to account for time, day and season in design and analysis of research on changes in mental health and well-being. It could also help inform programs such as mental health screening efforts, helplines and 24-hour support services.