Phototherapy Nadejda Alekseeva, MD PGY-IV Resident Department of Psychiatry LSUHSC-September 2006

Light Therapy (LT) Light Therapy (LT) The least invasive, most natural and effective treatment of Seasonal Affective D/O (SAD) The original theory behind LT was that it would cause a normalization of the phase-shift delay in SAD, to lengthen the photoperiod in winter in those with SAD and to suppress the production of melatonin by the pineal gland

Seasonal Affective Disorder Seasonal Affective Disorder There is much more seasonal difference in higher latitudes than in the lower There is much more seasonal difference in higher latitudes than in the lower In a significant portion of the population of the northern US, the shorter days of fall and winter precipitate SAD In a significant portion of the population of the northern US, the shorter days of fall and winter precipitate SAD

Seasonal Affective Disorder Seasonal Affective Disorder SAD is a syndrome that can consist of depression, fatigue, hypersomnolence, hyperphagia, carbohydrate craving, weight gain, and loss of libido SAD is a syndrome that can consist of depression, fatigue, hypersomnolence, hyperphagia, carbohydrate craving, weight gain, and loss of libido If these symptoms persist in the winter, abate as the days grow longer, and disappear in the summer, the diagnosis of SAD can be made If these symptoms persist in the winter, abate as the days grow longer, and disappear in the summer, the diagnosis of SAD can be made

Seasonal Affective Disorder Seasonal Affective Disorder Melatonin from the pineal gland has been implicated in SAD Melatonin from the pineal gland has been implicated in SAD Some individuals with SAD go to the other extreme in the spring and summer, experiencing a manic state Some individuals with SAD go to the other extreme in the spring and summer, experiencing a manic state

Seasonal Affective Disorder Seasonal Affective Disorder DSM Criteria for SAD: DSM Criteria for SAD: -can be applied to the pattern of MD episodes in Bipolar I d/o, Bipolar II d/o or MDD recurrent -can be applied to the pattern of MD episodes in Bipolar I d/o, Bipolar II d/o or MDD recurrent -there has been a regular temporal relationship between the onset of MD episode (appearance of MD episode in winter) -there has been a regular temporal relationship between the onset of MD episode (appearance of MD episode in winter) -full remission or change to mania in spring -full remission or change to mania in spring For the last 2 years, 2 SAD episodes For the last 2 years, 2 SAD episodes

Epidemiology of SAD Incidence of SAD in the general population is 4- 10%, with a higher incidence in women than men Incidence of SAD in the general population is 4- 10%, with a higher incidence in women than men SAD incidence increases in population further North SAD incidence increases in population further North People from Southern latitudes who move North may have an increased risk of SAD People from Southern latitudes who move North may have an increased risk of SAD Some individuals develop a tolerance to seasonal changes over time Some individuals develop a tolerance to seasonal changes over time

Seasonal Affective Disorder Seasonal Affective Disorder Decreased exposure to sunlight in the winter increases the risk of SAD Decreased exposure to sunlight in the winter increases the risk of SAD But studies of populations native to Iceland discovered a possible genetic adaptation to the low light of winter in the arctic But studies of populations native to Iceland discovered a possible genetic adaptation to the low light of winter in the arctic This population had a SAD prevalence of 1.2% This population had a SAD prevalence of 1.2% Another genetic finding: SAD occurs more often in relatives of those with SAD Another genetic finding: SAD occurs more often in relatives of those with SAD

Seasonal Affective Disorder Seasonal Affective Disorder The most commonly used SAD diagnostic research tools are the: The most commonly used SAD diagnostic research tools are the: -Seasonal Pattern Questionnaire (SPAQ) -Seasonal Pattern Questionnaire (SPAQ) -Structured Interview guide for the Hamilton Depression rating-Seasonal Affective D/O (SIGH-SAD) -Structured Interview guide for the Hamilton Depression rating-Seasonal Affective D/O (SIGH-SAD)

Mechanisms of Seasonal Changes in SAD Individuals with SAD have longer periods of melatonin synthesis at night in the winter Individuals with SAD have longer periods of melatonin synthesis at night in the winter Melatonin synthesis is triggered by darkness Melatonin synthesis is triggered by darkness Melatonin synthesis can be suppressed by application of LT Melatonin synthesis can be suppressed by application of LT

Role of Melatonin Melatonin is the immediate downstream metabolite of serotonin Melatonin is the immediate downstream metabolite of serotonin Low brain level of serotonin might contribute to SAD symptoms (hyperphagia and carb cravings) Low brain level of serotonin might contribute to SAD symptoms (hyperphagia and carb cravings) Increased carb cravings in SAD may be a coping mechanism that stimulates the release of serotonin Increased carb cravings in SAD may be a coping mechanism that stimulates the release of serotonin

Light Therapy Light Therapy Is a natural, noninvasive, effective, well- researched method of treatment for SAD Is a natural, noninvasive, effective, well- researched method of treatment for SAD Various Light temperatures and times of administration of LT have been studied Various Light temperatures and times of administration of LT have been studied Combination of morning and evening exposure appears to offer the best efficacy Combination of morning and evening exposure appears to offer the best efficacy

Light Therapy Been used to suppress the production of melatonin by the pineal gland Been used to suppress the production of melatonin by the pineal gland Light enters the retina, which in turn stimulates the suprachiasmatic nucleus of the hypothalamus Light enters the retina, which in turn stimulates the suprachiasmatic nucleus of the hypothalamus This in turn inhibits the pineal gland from converting serotonin to melatonin This in turn inhibits the pineal gland from converting serotonin to melatonin

What are the 4 components of bright light therapy? What are the 4 components of bright light therapy?

The 4 components of bright light therapy are: The 4 components of bright light therapy are: Intensity Intensity Timing Timing Duration Duration Wavelength Wavelength

What light intensity is necessary for melatonin suppression? What light intensity is necessary for melatonin suppression?

Light intensity greater than 2000 lux is necessary for melatonin suppression in most people Light intensity greater than 2000 lux is necessary for melatonin suppression in most people

What is the recommended use of bright light box in SAD? What is the recommended use of bright light box in SAD?

Exposure to the eyes of diffuse visible light with an intensity of at least 2500 lux daily, preferably in AM, for at least 2 h Exposure to the eyes of diffuse visible light with an intensity of at least 2500 lux daily, preferably in AM, for at least 2 h Most light boxes produce 2500 lux at a distance of 3 feet, and light intensity is inversely related to the square root of distance of the eyes to the light source Most light boxes produce 2500 lux at a distance of 3 feet, and light intensity is inversely related to the square root of distance of the eyes to the light source

Using the 2500 lux box at 1.5 feet from the eyes produces 10,000 lux, and the duration of treatment can be reduced, as 30 min at 10,000 lux is equivalent to 2 h at 2500 Using the 2500 lux box at 1.5 feet from the eyes produces 10,000 lux, and the duration of treatment can be reduced, as 30 min at 10,000 lux is equivalent to 2 h at 2500

How long does it take to show a response to bright light? How long does it take to show a response to bright light?

Response to bright light therapy usually begins within 3 to 4 days, with full response in 1 to 2 weeks Response to bright light therapy usually begins within 3 to 4 days, with full response in 1 to 2 weeks when LT stopped, relapse can occur in 3 to 4 days when LT stopped, relapse can occur in 3 to 4 days

Light Therapy Light Therapy Has an overall positive treatment response of up to 70%, with rarely any side effects Has an overall positive treatment response of up to 70%, with rarely any side effects

Combination of LT and CBT demonstrated a lower remission rate than LT alone Combination of LT and CBT demonstrated a lower remission rate than LT alone

Light Therapy Light Therapy Experimental treatment extended to other conditions: Experimental treatment extended to other conditions: Non-seasonal mood d/o Non-seasonal mood d/o Alzheimer’s disease Alzheimer’s disease Circadian-related sleep d/o Circadian-related sleep d/o Jet lag Jet lag Eating d/o Eating d/o

LT improves nocturnal sleep in people with dementia LT improves nocturnal sleep in people with dementia LT reverse age-associated disturbances of circadian sleep-wake rhythm LT reverse age-associated disturbances of circadian sleep-wake rhythm LT prevent the age-associated decrease in the number of vasopressin-secreting neurons in the suprachiasmic nuclei of the hypothalamus LT prevent the age-associated decrease in the number of vasopressin-secreting neurons in the suprachiasmic nuclei of the hypothalamus

Despite the growth in clinical and research programs, there is an absence of recognition and support for LT Despite the growth in clinical and research programs, there is an absence of recognition and support for LT Most insurers do not pay for this treatment Most insurers do not pay for this treatment Most residency training programs do not provide training in Light Therapy Most residency training programs do not provide training in Light Therapy