Stress and dreams

The correlation is one of the better-established findings in the field: periods of higher waking stress bring more frequent and more distressing dreams, and more nightmares.

What changes

• Nightmare frequency rises.
• Negative emotion in ordinary dreams rises even when the dream is not a nightmare.
• Threatening content becomes more common: being chased, being unable to move, losing something.

Two competing readings

The regulation view holds that dreaming processes emotional material, and that a nightmare is that system under load or failing. On this account distressing dreams during a hard period are the system working hard, not malfunctioning.

The simulation view holds that dreams rehearse threats, and that a brain under threat rehearses more.

Both make sense of the correlation. Neither is established, and you should be suspicious of any site that tells you which one your dream was doing.

What this justifies you actually doing

• Log the stress rating. The pattern dashboard compares nightmare frequency on high-stress and low-stress nights, but it refuses to report the comparison below twenty logged nights, because a "pattern" from five nights is noise.
• Treat a nightmare spike as information about your life, not as a message inside the nightmare.
• If nightmares are frequent, distressing and persistent, that is a treatable problem with an evidence-backed treatment. See the nightmare pages rather than trying to interpret your way out of it.