What is seasonal affective disorder (SAD)?
This is a disorder that usually causes depression in the fall and winter months in women. It is associated with increased sleep and increased appetite, especially carbohydrate cravings. It is usually treated with light therapy and can also benefit from restricting sleep time.
What is phototherapy?
Phototherapy is the use of daylight or artificial light (10,000 lux) to affect sleep or wake and mood. Special therapy lights are used to avoid excessive UV exposure which could lead to damage to the retina or cancer. Light can also trigger mania or bipolar disorder and should not be used in people with these conditions. It is usually given for 30-60 minutes at a time with the person sitting several feet away and at rest (exercise produces hormones which block the effect of light). Light acts to directly influence melatonin, which is the hormone the brain uses to manage the sleep-wake schedule. Other than daylight, a sleep physician should manage light therapy.
How does depression and sleep interact?
It is well known that depression will lead to increased difficulty with sleep, and it is also known that sleep disorders can lead to an increased risk of depression. Sleep deprivation (not enough sleep), can improve depression, but can also worsen mania (overactivity). Getting enough sleep, but having abnormal sleep, can lead to increased paranoia, which is often associated with mental health disorders, such as schizophrenia. People who have anxiety can have increased insomnia and may spend excessive time during the night watching the clock and being upset about their poor quality of sleep.
Can someone commit a crime or perform violent acts in their sleep?
Criminal activity can be related to sleep disorders and their treatments, but these are usually due to impaired driving and accidents, rather than pre-meditated events. The victims are often completely unknown to the affected individual. Sleepwalking can lead a person to do daily routine activities which are already patterned in their brain, such as opening doors, putting on clothing, et cetera. Sleep walking will not cause someone to do something out of character, unprovoked and unrelated to their usual rituals, i.e. to rob a bank or go to murder someone for revenge or financial gain.