Circadian Therapy in Bipolar Disorder: What You Need to Know

Thirty international experts agree

STUDY: Crouse JJ et al, Bipolar Disorders 2026

STUDY TYPE: Expert consensus (Delphi study)

FUNDING: National Health and Medical Research Council (Australia)

Background

Circadian disruption is a core part of bipolar disorder’s biology. Genetic studies link bipolar disorder to the circadian CLOCK genes, and randomized trials support bright light therapy, social rhythm therapy, and dark therapy. Yet most training programs and guidelines barely mention it. This task force set out to define what clinicians need to know.

Disclaimer: I was an author on this paper.

The Study

• Thirty psychiatrists and researchers from 15 countries, most with decades of clinical experience.
• Rated nearly 750 statements on circadian science and chronotherapy across three Delphi rounds.
• A statement reached consensus if 80% or more rated it essential or important.

Results

The panel reached consensus on 342 statements. Here are some highlights:

• Evening chronotypes (night owls) have a higher risk of mood-disorders
• Lithium normalizes the expression of circadian rhythm genes and may work in part by shifting circadian rhythms, allowing night owls to fall asleep earlier
• Sleep disturbance is an early warning sign of mania worth acting on
• Bright light therapy works best at 7,000 to 10,000 lux, mid-day, for 30 to 120 minutes
• Blue-blocking glasses, worn from evening (typically 6:00 pm) until bedtime and followed by a pitch-dark bedroom, can speed resolution of mania in hospitalized patient
• Social rhythm therapy works by having patients track five daily anchors: wake time, first contact with another person, start of formal activities, dinner, and bedtime

The full set of circadian facts is free and summarized below:

Practice Implications

1. Talk to patients about the circadian nature of bipolar.
2. It is practical, destigmatizing, and empowers them to make changes that prevent new episodes.