AM I DEPRESSED OR IS IT JUST OVERTHINKING??

Image source: How to stop overthinking: 10 effective tips by Lachlan Brown

By, Dr.Shadab Kamal

TOPICS COVER:

What is circadian rythym?
How circadian rythym affects your mental health?
Deeper Insights About Melatonin
cortisol functions in maintaining circadian rythym.
what exactly the word depression entitles to?
What can be the possible causes of depression-like behaviour?

Oh my God! I feel like I am going in depression. I am not even thinking about it yet I am sad, I do not feel like going out, meeting people, going to work or study. I am just being so hopeless.
What is happening to me? This is not me at all.

After wasting the whole day, you ended up in bed to sleep but in your great mind here pops some fancy thoughts. You tossed a couple of times left to right and right to left. Sometimes supine sometimes prone and whoosh!

I can see a light in your room now, where it’s coming from?
Hold on!! You are on your phone now??? Perhaps searching a way out of your thoughts!!!
And the clock ticks 12..2..4..5……AM!
Its almost dawn. Shit!! A light to frustration and despair.

Day 2:

You wakeup (your room is definitely going to be bright) and clock says “GOOD AFTERNOON”, it is already noon!!
Your circadian rythym is not matching the world clock. And here you start mentoring your brain “I am sleeping for only 06 to 07 hours” that’s healthy…
However, I sense some guilt in your inner voice.

By now I am sure you are smiling and figuring that this story almost relates you.
If you wanna understand the phenomenon, here’s a bit of science.

If not, you can skip to click here to what exactly the word depression entitles to?

What is circadian rythym?
A circadian rythym is a natural 24- hours endogenous molecular clock  that is running in the background of your brain. In simpler words, you can call it a sleep-wake cycle monitorization unit and it works on the principle of your day (light) and night(dark) routine by osscilating every 24 hours.

It is controlled by a part of our brain called hypothalamus. A bidirectional relationship exists between mood disorders and circadian rhythms. Mood disorders are often associated with disrupted circadian clock-controlled responses, such as sleep and cortisol secretion, whereas disruption of circadian rhythms via jet lag, night-shift work, or exposure to artificial light at night, can precipitate or exacerbate affective symptoms in susceptible individuals. (1)

How circadian rythym affects your mental health?
Exposure to light at night perturbs the circadian system because light is the major entraining cue used by the body to discriminate day and night. When exposure to light is mistimed or nearly constant, biological and behavioral rhythms can become desynchronized, leading to negative consequences for health. (2)

Melatonin and cortisol the two key hormones play their  role in maintaining effective sleep wake cycle.
Melatonin is referred as a “sleep hormone” or “hormone of darkness”, named after its surge at night time when the surroundings are dark.  However, Cortisol (a glucocorticoid) is referred as a “stress hormone” that is in higher concentrations early morning as you rise.

Deeper Insights About Melatonin
Melatonin is synthesized by pineal gland ( a deep seated part of brain), produced from an inhibitory neurotransmitter Serotonin that regulates and balances the affect of excitatory neurotransmitters of brain. Serotonin  is made from tryptophan (an amino acid) through a cascade of enzymatic reactions.
Note that,  Pineal gland which is interestingly located outside the blood brain barrier, does not allow serotonin to enter the BBB via serotonergic pathways and this perhaps accounts for the ability of the pineal gland to have a large uptake of tryptophan leading to a high melatonin production and secretion in response to darkness.

However, the suprachiasmatic nucleus ( SCN , a master clock in hypothalamus, as discussed earlier) also has some modest direct projections to presympathetic neurons in the paraventricular nucleus, and therefore may drive some sympathetic rhythms directly, particularly those that regulate sympathetic drive to the pineal gland, and therefore melatonin secretion. (3)

The SCN functions as the central circadian oscillator. Clocks throughout the body remain synchronized with one another by responding to signals from the SCN, either through direct neural inputs or indirect signals such as humoral, behavioral, or other physiological rhythms. For example, timing of feeding and body temperature can help synchronize peripheral oscillators. Aberrant light exposure that disrupts these rhythms may drive downstream dysregulation of circadian rhythms in peripheral systems. Thus, via suppression of melatonin rhythm, light at night has the potential to substantially alter physiology and behavior.  (1)

 Cortisol functions in maintaining circadian rythym.
Cortisol is an essential steroid hormone secreted by the adrenal gland and like many other physiological processes in the body has a circadian rhythm. This rhythm is also regulated by the main circadian oscillator (pacemaker) in the suprachiasmatic nucleus (SCN).  Normal individuals, without disease of the hypothalamo—pituitary— adrenal (HPA) axis, at midnight, have very low or undetectable cortisol levels that build up overnight to peak first thing in the morning. Cortisol levels then decline slowly throughout the day. (4) The HPA axis receives input from the central pacemaker which controls the circadian release of corticotrophin-releasing hormone (CRH) in the paraventricular nucleus, this is also stimulated by physical and emotional stressors. CRH in turn stimulates the release of adrenocorticotrophic hormones (ACTH) from the corticotroph cells in the anterior pituitary, and thence the glucocorticoid cortisol from the adrenal cortex. In turn, cortisol exerts inhibitory effects at pituitary and hypothalamic levels, in a classical negative feedback loop although there is no feedback on the SCN. (4)[Oster et al. 2006b].

A bidirectional relationship exists between cortisol rhythmic activity and the sleep wake cycle (SWC) although both systems have two separate generators in the SCN [Spath-Schwalbe et al. 1992]. Sleep disturbances associated with increased daytime fatigue have been reported for patients with adrenal insufficiency [Lovas et al. 2003]. Rapid eye movement (REM) sleep latency and time may vary in patients with adrenal insufficiency on conventional treatment thus interrupting sleep continuity  [Garcia-Borreguero et al. 2000]. (4)

What exactly the word depression entitles to?
Depression or MDD (major depressive disorder as per DSM-5 criterion ) lies under the category of Mood Disorder and is describes as alterations in mood, typically increased sadness and/or irritability that is accompanied by at least one of the following psychophysiological symptoms: alterations in sleep, sexual desire, or appetite, inability to experience pleasure, slowing of speech or actions, crying, and suicidal thoughts.

Picture Source: https://www.researchgate.net/figure/Diagnostic-criteria-for-major-depressive-disorder-MDD-in-the-DSM-5-and-ICD-10_tbl3_296607799

Now take some time to evaluate if you fall in this criteria. If not, perhaps you are not suffering from this mood disorder. The other way around is a depression-like behavior. [A common misnomer of depression (MDD) but have the ability to develop it in future].

Note that, the neurotransmitter I discussed earlier “serotonin” is the one that plays a  major role in precipitating low mood and the disruption of circadian rythym can cause disproprortion of this neurotransmitter making the person vulnerable to become a diagnosed case of Depression.

What can be the possible causes of depression-like behaviour?
If I want to sum up, all the possible causes in just word , I will state “stress”.

1.  Death of a loved one
2.  Loss of a job
3.  Financial burdens/obligations
4.  Divorce
5.  Getting married
6.  Any sort of physical and emotional trauma (harassment, violence, rape, abuse, accident, burns)
7.  Financial trauma and emotional trauma (theft)
8.  Taking care of a sick patient

These all are external stresses i.e. induced. However, there are internal stresses that comes from within. And the major one is “Over-thinking”. Worrying unnecessarily can cause a shift in your hormones that can precipitate low mood.

Let’s take an example,

• of a work environment where your boss is not too appreciating. In such an environment, you will always be feel pressurized, as you do not want to loose your job and self-esteem.

• Likewise, parent stresses; how our kids should move in future? Uncertainty about their future, worrying about their marriages… and many more..

• Or, take this covid-19 pandemic. News channels, social media, news papers are literally shouting.. disrupting mental health. Indeed they are a source of awareness and keeps all of us up to date, still we can see increasing numbers of patients seeking help from psychotherapist and psychiatrist.

Wrapping up all in a nutshell,
From the above listed depression (MDD) symptoms, if five of them from the chart along with a low mood are not lasting for about 2 weeks. You are over thinking!! You are pushing your mind and body to develop it. You need to STOP!!

If you are suffering as per the diagnostic criteria without a single day break of healthy happy mood till 2 weeks, you need serious help! Consult a psychotherapist/psychiatrist…

Do not listen to people/ do not care what the society will think.
Just as all parts of your body needs a doctor when you fall ill, so does your brain related issues. Sounds Perfectly normal? It is… normal.

Works Cited
1. Circadian rhythm disruption and mental health. Walker, W.H., Walton, J.C., DeVries, A.C. et al. 2020, Transl Psychiatry. https://doi.org/10.1038/s41398-020-0694-0

2. Timing of light exposure affects mood and brain circuits. Bedrosian, T., Nelson, R. jan 2017, s.l. : Transl Psychiatry, 2017. 0028-0836. https://doi.org/10.1038/tp.2016.262

3. Clifford B. Saper,Ruth L. Stornetta. science direct. [book auth.] Ruth L. Stornetta Clifford B. Saper. The rat nervous system (4th edition). s.l. : Elsevier, 2015. https://doi.org/10.1016/B978-0-12-374245-2.00023-1

4. Replication of cortisol circadian rhythm: new advances in hydrocortisone replacement therapy. Sharon Chan, Miguel Debono. s.l. : sage journal, 2010. https://doi.org/10.1177/2042018810380214