Phototherapy

Nadejda Alekseeva, MDNadejda Alekseeva, MDPGY-IV ResidentPGY-IV Resident

Department of Psychiatry Department of Psychiatry LSUHSC-September 2006LSUHSC-September 2006

Light Therapy (LT)Light Therapy (LT)

The least invasive, most natural and The least invasive, most natural and effective treatment of Seasonal Affective effective treatment of Seasonal Affective D/O (SAD)D/O (SAD)

The original theory behind LT was that it The original theory behind LT was that it would cause a normalization of the phase-would cause a normalization of the phase-shift delay in SAD, to lengthen the shift delay in SAD, to lengthen the photoperiod in winter in those with SAD photoperiod in winter in those with SAD and to suppress the production of and to suppress the production of melatonin by the pineal glandmelatonin by the pineal gland

Seasonal Affective DisorderSeasonal Affective Disorder

• There is much more seasonal There is much more seasonal difference in higher latitudes than in difference in higher latitudes than in the lowerthe lower

• In a significant portion of the In a significant portion of the population of the northern US, the population of the northern US, the shorter days of fall and winter shorter days of fall and winter precipitate SADprecipitate SAD

Seasonal Affective DisorderSeasonal Affective Disorder

• SAD is a syndrome that can consist of SAD is a syndrome that can consist of depression, fatigue, hypersomnolence, depression, fatigue, hypersomnolence, hyperphagia, carbohydrate craving, hyperphagia, carbohydrate craving, weight gain, and loss of libidoweight gain, and loss of libido

• If these symptoms persist in the If these symptoms persist in the winter, abate as the days grow longer, winter, abate as the days grow longer, and disappear in the summer, the and disappear in the summer, the diagnosis of SAD can be madediagnosis of SAD can be made

Seasonal Affective Seasonal Affective DisorderDisorder

• Melatonin from the pineal gland has Melatonin from the pineal gland has been implicated in SADbeen implicated in SAD

• Some individuals with SAD go to the Some individuals with SAD go to the other extreme in the spring and other extreme in the spring and summer, experiencing a manic statesummer, experiencing a manic state

Seasonal Affective Seasonal Affective DisorderDisorder• DSM Criteria for SADDSM Criteria for SAD::

• -can be applied to the pattern of MD episodes -can be applied to the pattern of MD episodes in Bipolar I d/o, Bipolar II d/o or MDD recurrentin Bipolar I d/o, Bipolar II d/o or MDD recurrent

• -there has been a regular temporal -there has been a regular temporal relationship between the onset of MD episode relationship between the onset of MD episode (appearance of MD episode in winter)(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 episodesFor the last 2 years, 2 SAD episodes

Epidemiology of SADEpidemiology of SAD

• Incidence of SAD in the general population Incidence of SAD in the general population is 4-10%, with a higher incidence in is 4-10%, with a higher incidence in women than menwomen than men

• SAD incidence increases in population SAD incidence increases in population further Northfurther North

• People from Southern latitudes who move People from Southern latitudes who move North may have an increased risk of SADNorth may have an increased risk of SAD

• Some individuals develop a tolerance to Some individuals develop a tolerance to seasonal changes over timeseasonal changes over time

Seasonal Affective Seasonal Affective DisorderDisorder• Decreased exposure to sunlight in the Decreased exposure to sunlight in the

winter increases the risk of SADwinter increases the risk of SAD

• But studies of populations native to Iceland But studies of populations native to Iceland discovered a possible genetic adaptation to discovered a possible genetic adaptation to the low light of winter in the arcticthe low light of winter in the arctic

• This population had a SAD prevalence of This population had a SAD prevalence of 1.2%1.2%

• Another genetic findingAnother genetic finding: SAD occurs more : SAD occurs more often in relatives of those with SADoften in relatives of those with SAD

Seasonal Affective Seasonal Affective DisorderDisorder

• The most commonly used SAD The most commonly used SAD diagnostic research tools are the:diagnostic research tools are the:

• -Seasonal Pattern Questionnaire -Seasonal Pattern Questionnaire (SPAQ)(SPAQ)

• -Structured Interview guide for the -Structured Interview guide for the Hamilton Depression rating-Seasonal Hamilton Depression rating-Seasonal Affective D/O (SIGH-SAD)Affective D/O (SIGH-SAD)

Mechanisms of Seasonal Mechanisms of Seasonal Changes in SADChanges in SAD

• Individuals with SAD have longer Individuals with SAD have longer periods of melatonin synthesis at periods of melatonin synthesis at night in the winternight in the winter

• Melatonin synthesis is triggered by Melatonin synthesis is triggered by darknessdarkness

• Melatonin synthesis can be Melatonin synthesis can be suppressed by application of LTsuppressed by application of LT

Role of MelatoninRole of Melatonin

• Melatonin is the immediate Melatonin is the immediate downstream metabolite of serotonindownstream metabolite of serotonin

• Low brain level of serotonin might Low brain level of serotonin might contribute to SAD symptoms contribute to SAD symptoms (hyperphagia and carb cravings)(hyperphagia and carb cravings)

• Increased carb cravings in SAD may Increased carb cravings in SAD may be a coping mechanism that be a coping mechanism that stimulates the release of serotoninstimulates the release of serotonin

Light TherapyLight Therapy

• Is a natural, noninvasive, effective, well-Is a natural, noninvasive, effective, well-researched method of treatment for researched method of treatment for SADSAD

• Various Light temperatures and times of Various Light temperatures and times of administration of LT have been studiedadministration of LT have been studied

• Combination of morning and evening Combination of morning and evening exposure appears to offer the best exposure appears to offer the best efficacyefficacy

Light TherapyLight Therapy

• Been used to suppress the production Been used to suppress the production of melatonin by the pineal glandof melatonin by the pineal gland

• Light enters the retina, which in turn Light enters the retina, which in turn stimulates the suprachiasmatic nucleus stimulates the suprachiasmatic nucleus of the hypothalamusof the hypothalamus

• This in turn inhibits the pineal gland This in turn inhibits the pineal gland from converting serotonin to melatoninfrom converting serotonin to melatonin

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

• The 4 components of bright light The 4 components of bright light therapy are:therapy are:

• IntensityIntensity

• TimingTiming

• DurationDuration

• WavelengthWavelength

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

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

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

• Exposure to the eyes of diffuse visible Exposure to the eyes of diffuse visible light with an intensity of at least 2500 light with an intensity of at least 2500 lux daily, preferably in AM, for at least lux daily, preferably in AM, for at least 2 h2 h

• Most light boxes produce 2500 lux at a Most light boxes produce 2500 lux at a distance of 3 feet, and light intensity is distance of 3 feet, and light intensity is inversely related to the square root of inversely related to the square root of distance of the eyes to the light sourcedistance of the eyes to the light source

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

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

• Response to bright light therapy Response to bright light therapy usually begins within 3 to 4 days, usually begins within 3 to 4 days, with full response in 1 to 2 weekswith full response in 1 to 2 weeks

• when LT stopped, relapse can occur when LT stopped, relapse can occur in 3 to 4 daysin 3 to 4 days

Light TherapyLight Therapy

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

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

Light TherapyLight Therapy

• Experimental treatment extended to Experimental treatment extended to other conditions:other conditions:

• Non-seasonal mood d/oNon-seasonal mood d/o

• Alzheimer’s diseaseAlzheimer’s disease

• Circadian-related sleep d/oCircadian-related sleep d/o

• Jet lagJet lag

• Eating d/oEating d/o

• LT improves nocturnal sleep in people LT improves nocturnal sleep in people with dementiawith dementia

• LT reverse age-associated disturbances LT reverse age-associated disturbances of circadian sleep-wake rhythmof circadian sleep-wake rhythm

• LT prevent the age-associated decrease LT prevent the age-associated decrease in the number of vasopressin-secreting in the number of vasopressin-secreting neurons in the suprachiasmic nuclei of neurons in the suprachiasmic nuclei of the hypothalamusthe hypothalamus

• Despite the growth in clinical and Despite the growth in clinical and research programs, there is an research programs, there is an absence of recognition and support absence of recognition and support for LTfor LT

• Most insurers do not pay for this Most insurers do not pay for this treatmenttreatment

• Most residency training programs do Most residency training programs do not provide training in Light Therapynot provide training in Light Therapy