Recently, the Diagnostic and Statistical Manual
of Mental Disorders, fifth edition, has changed the name “seasonal affective disorder,”
or SAD, to “depressive disorder with seasonal pattern.” The new name is not as catchy as “SAD,”
or “SAD” but it does describe the condition more precisely. That’s because depressive disorder with
seasonal pattern is not really a distinct disease, but rather depression that worsens
at the same time each year, usually in the late fall and winter. So let’s first review depression. Depression, or major depression, is a serious
condition where someone’s life isn’t enjoyable and it interferes with someone’s day-to-day
life, like working, studying, eating, and sleeping. The causes of depression aren’t fully known,
but it’s thought to involve a deficiency of monoamine neurotransmitters in the brain,
like dopamine, norepinephrine, and especially serotonin. In depressive disorder with seasonal pattern,
there’s a strong relationship with the circadian rhythm, which is an internal clock that keeps
your body in tune with the rising and setting of the sun. At the base of the brain, is a region called
the hypothalamus, and within it are a group of neurons located in a specific spot called
the suprachiasmatic nucleus or SCN. The neurons in the suprachiasmatic nucleus
get information about light from optic nerves, and use that information to run the circadian
rhythm. The suprachiasmatic nucleus relays that information
to the pineal gland, a tiny cone-shaped structure near the hypothalamus. And when it’s dark out, the pineal gland
releases the hormone melatonin, which is chemically related to serotonin. Melatonin lowers your heart rate and body
temperature, which helps you go to sleep. When it’s light outside, the pineal gland
stops releasing melatonin, and that has the opposite effect – raising your heart rate
and body temperature, and that keeps you awake. A risk factor for developing depressive disorder
with seasonal pattern is having a sleep phase delay, which is when a person makes too little
melatonin at night. This can be due to things like decreased sensitivity
to changes in light, problems with the communication between the retina and the hypothalamus, and
even external sources of light like late-night computer use. A sleep phase delay can result in a person’s
internal clock having more than the standard 24 to 25 hours in a day, which might sound
awesome – but actually it means that a person may not be able to sleep until at least eighteen
hours after they woke up that day. Day after day, that quickly becomes exhausting. It can be hard for anyone to adjust to the
late sunrises and early sunsets of winter, especially those who live in higher latitudes. But for those with a disordered circadian
rhythm, the shorter days seems to somehow interfere with monoamine production, causing
the person to become depressed. Another mechanism that may be involved relates
to vitamin D, which is largely obtained in a reaction that relies on sunlight. Vitamin D is involved in the synthesis of
serotonin and dopamine in the brain, and if someone is already deficient in vitamin D
decreased sunlight, and therefore decreased synthesis of monoamines, might push a vitamin-D
deficient person into depression. Both the sleep phase delay and vitamin-D deficiency
ideas hold promise, but they don’t yet explain those few people who get depressive disorder
with seasonal pattern in the summer. Symptoms of depressive disorder with seasonal
pattern are similar to those of depression, and include intense feelings of worthlessness
or guilt, and a lack of enjoyment in activities they took pleasure in during other times in
the year. They may find it hard to concentrate, and
in severe cases, have thoughts of death or suicide. So, when it comes to diagnosis, for the depression
to be truly seasonal, it must occur in the same season each year for at least two years
in a row, and the symptoms must diminish or disappear with the new season. It’s also important not to confuse seasonally-triggered
depression with depression caused by recurring psychological or social stressors, like having
job pressures or living alone during certain months of the year. Treatment of depressive disorder with seasonal
pattern usually includes light therapy, medication, and psychotherapy. In light therapy, a person sits close to an
intensely bright light box for 30 to 90 minutes every morning. Unlike the light bulbs you’d normally use
around your house, light-therapy boxes have light wavelengths that allow the skin to produce
vitamin D. Antidepressants can also be helpful – for example, selective serotonin reuptake
inhibitors can increase serotonin levels, and bupropion can increase norepinephrine
and dopamine levels. Finally, cognitive behavioral therapy can
be particularly useful in helping people identify and manage their feelings. Alright, as a quick recap, seasonal affective
disorder, otherwise known as depressive disorder with seasonal pattern is a depression that
recurs in the same season for at least two years in a row, and the symptoms must diminish
or disappear with the new season. It usually occurs in the fall and winter months,
and may be related to a dysregulated circadian rhythm or vitamin D deficiency.

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19 thoughts on “Seasonal affective disorder – causes, symptoms, diagnosis, treatment, pathology

  1. I'm doing a school assignment where i have to make a psycho-educative programme.
    This helped me out so much, both for the information and the design of the video. Big cheers!

  2. I can know about the seasonal effects on hemisphere to courses schizophrenia u can made video about this topic plz☺️☺️

  3. I become sad and depressed after sun set . I am taking antidepressants for last 4 years.
    Please tell me some guidelines

  4. Cause of the depression isn't fully known?
    But it is! This world and life are fallen, horrid, and constantly going downwards spiral. It's statistics, human ecology, conservation biology and epidemiological medical studies that keep proving this.
    At this point, depression is mostly caused by the environment, and is a natural response in objective people with compromised ability of self-fooling (in a wand of a better word) and denial.

  5. Does anyone get it where you can smell autumn in the air, and it brings past memories flooding back and makes you really sad and feel so alone?

  6. This is just for whiny teenagers who don't like the cold. Depression is a serious issue caused by actual problems in your life and your mind. Not the temperature outside.

  7. I’m happier in the spring and summer . I still have my bad days but when I don’t see the sun in the fall and winter I get severely down .

  8. I dont get much happier than below average during the summer or spring but the winter really fucks with my brittle will to live.

  9. Depression I think is possibly corelated to personality types. I believe all are capable of becoming depressed but some more inclined than others. I'm an infj male and around october of each year I go through a severe depression cycle.

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