Sleep + circadian rhythms 2

Question 1

The effect of light therapy in the evening is…

Answer 1

Postpones circadian phase, shift work/jet lag can be regulated by administering light and darkness

Question 2

Explain circadian rhythm lifespan changes

Answer 2

1st months - scattered sleep. In elderly, rhythm is lost and sign of Alzheimers. Adolescence - phase shift - sleep later and wake up later. Reversed in middle age

Question 3

Blue enriched light is good and bad because?

Answer 3

Reading comprehension not significantly increased (bad), reading speed significantly increased (good)

Question 4

Explain advantages of red enriched light

Answer 4

Calmer after 5 mind of red, positive impact on mood

Question 5

Which colour light suppresses melatonin suppression?

Answer 5

Blue light

Question 6

Name the 3 chronobiological interventions

Answer 6

Bright light therapy, exogenous melatonin (oral intake), sleep deprivation theory

Question 7

What nm has the strongest impact?

Answer 7

460nm

Question 8

Explain the 2 brain mechanisms related to light

Answer 8

Serotonin - light is related to serotonin reuptake. Beginning of light exposure - activity all over cortex after 20 minutes.

Question 9

The diagnostic criteria for SAD is…(3)

Answer 9

2+ depressive symptoms/episodes in autumn/winter, spontaneous remission in spring/early summer, atypical symptoms e.g. daytime tiredness, increased sleep, weight gain

Question 10

Explain Barkmann, Wessolouski & Schulte-Markwort’s research into dynamic lights in classrooms

Answer 10

Control - 300lux, 400k. Working highly concentrated - 1060lux, 5800k. Activating blue light - 675lux. Calm down (red-yellow) - 325lux.

Question 11

Which time of day is best for light therapy?

Answer 11

Better earlier in the day. Light 3.5hrs after body temp minimum to change rhythm and treat disorders

Question 12

List the things light therapy can treat

Answer 12

SAD/subsyndromal SAD, bulimia, depression, bipolar, Alzheimers/dementia, chronic sleep problems, shift work, jet lag

Question 13

What are the effects of LED screens?

Answer 13

LED flatscreen had lower sleepiness, whilst sleepiness increased with the flatscreen. Frontal activity is lower

Question 14

What did a study compare as treatments to depression? (4)

Answer 14

Placebo, SSRI, bright light therapy, bright light therapy combined with SSRI

Question 15

What were the findings of the study comparing treatments to depression?

Answer 15

Combiantion of bright light therapy and SSRI does best. SSRI effective in morning, light stronger than placebo.

Question 16

SAD prevalence increases with…

Answer 16

Latitude

Question 17

Explain the epidemiology of SAD and subsyndromal SAD

Answer 17

SAD = 2% men, 3% women. Subsyndromal = 7% men, 10% women

Question 18

Describe the effectiveness of sleep deprivation therapy

Answer 18

Effective in 60% of those with MDD. Rapidly acting, but relapse after 1st night of sleep.

Question 19

How does sleep deprivation therapy work?

Answer 19

It resets the clock gene machinery