Sleep, Physical Activity, and Mood Among People Seeking Mental Health Care.

Sleep duration was associated with subsequent mood through an inverse U-shaped relationship, with both short and long sleep duration associated with poorer mood.

• The quadratic term for sleep duration predicting mood was b = -0.027 (95% CI, -0.031 to -0.023)
• The study involved 1476 participants (mean [SD] age, 36.5 [14.2] years; 1062 [72.0%] female) seeking mental health care
• Mood was measured on a scale of 1 (worst mood) to 10 (best mood) via daily participant report
• Sleep was measured objectively using wrist-based actigraphy over a 12-month period

Patients varied substantially in their optimal sleep duration for peak mood, with a mean optimal sleep duration of 6.8 hours.

• Mean (SD) optimal sleep duration for peak mood was 6.8 (1.9) hours across participants
• The SD of 1.9 hours indicates substantial individual variation in optimal sleep duration
• This finding highlights that a single universal sleep duration recommendation may not be appropriate for all individuals seeking mental health care

Physical activity was positively associated with subsequent mood, with diminishing associations at higher than usual activity levels for a given individual.

• Linear term for step count predicting mood: b = 0.160 (95% CI, 0.149 to 0.162; P < .001)
• Quadratic term for step count predicting mood: b = -0.022 (95% CI, -0.027 to -0.017; P < .001)
• The negative quadratic term indicates diminishing returns on mood at higher-than-usual physical activity levels for that individual
• Physical activity was measured objectively as step count via wrist-based actigraphy

Daily mood was bidirectionally associated with subsequent sleep in a wavelike manner.

• Linear term for mood predicting subsequent sleep: b = -1.377 (95% CI, -1.877 to -0.877; P < .001)
• Quadratic term for mood predicting subsequent sleep: b = -0.394 (95% CI, -0.765 to -0.023; P = .037)
• The association was described as 'wavelike,' indicating a non-monotonic relationship between mood and subsequent sleep

Daily mood was bidirectionally associated with subsequent step count in a wavelike manner.

• Linear term for mood predicting subsequent step count: b = 0.020 (95% CI, 0.003 to 0.030; P = .02)
• Quadratic term for mood predicting subsequent step count: b = -0.010 (95% CI, -0.020 to -0.001; P = .03)
• The association was described as 'wavelike,' indicating a non-monotonic relationship between mood and subsequent physical activity

The study enrolled 1476 participants seeking mental health care at a university academic medical center over approximately two and a half years.

• Participants were enrolled between May 13, 2020, and December 12, 2022
• Mean (SD) age was 36.5 (14.2) years; 1062 (72.0%) were female
• Data analysis was performed from September 2024 to June 2025
• This was a 12-month cohort study using within-person linear mixed-effects models, enabling within-person rather than only between-person comparisons

The study measured three sleep-related variables objectively via actigraphy: total sleep time, interrupted nighttime sleep, and napping.

• Objective, wrist-based actigraphy was used for all sleep and physical activity measures
• Sleep measures included total sleep time, interrupted nighttime sleep, and napping
• Physical activity was captured as step count
• Linear mixed-effects models were used to estimate associations among sleep, physical activity, and mood scores