Depressed In Winter And Summer

  • Suruthy Mary Joseph Bachelor in Biomedical Science (IBMS)- BSc in University of Portsmouth, UK
  • Chloe Vilenstein Master's degree, Neuroscience, Ecole normale supérieure, Paris, France


Mind is a blog suggesting that there is such a thing as seasonal depression influenced by winter and summer seasons, giving the term seasonal affective disorder with depression.   

Definition of SAD and depression

Seasonal affective disorder (SAD) is the seasonal pattern in which an individual experiences depression. SAD is assumed to have depression causing a shift in the weather or being high in temperature latitude.1 

Importance of understanding the link

We are usually affected by the weather, whether it is winter or summer. We feel lazy, and our mood is dropping, which can lead to worse sleeping patterns. Yet, if the feeling persists and interferes with your day-to-day life, then it turns out to be depression.1 

Thus, you need to be diagnosed with SAD. 

Symptoms of SAD

The proper symptoms of SAD differ in individuals as it has to do with how people are feeling. For instance, the lack of energy is detectable when a person feels no motivation, is unable to concentrate, your mood is low, and you do not want to be around people.1

Anxiety is the most constant symptom, and the lack of energy can be frustrating as we are unable to do work or be productive.1

The sleeping pattern depends on an individual's depression, having much to no sleep depending on the season. Much worse complications such as having a cold being suicidal from depressing thoughts or having no appetite.1

Depressive symptoms

Depression symptoms are classified into different categories.

 Firstly, the signs of depression indicate the feeling felt. I was upset, empty, and useless, feeling isolated and having difficulty relating to people. No self-confidence and feeling tired all the time are SAD signs.2

Secondly, the behavioural pattern shows avoidance of social events, suicidal thoughts, self-harming and difficulty expressing and formulating thoughts and needs.2

Then, we have the psychotic symptoms. The term demonstrates paranoia and delusions to the point of hearing voices. Depression correlates to mood regulation such that it is easy to create false sensations.2 

The signs and symptoms tend to accumulate into the suicidal phase. An individual will feel low in confidence. Self-harm is experiencing thoughts that are difficult to manage.2

Anxiety symptoms usually follow when we are trying to focus on work to distract from the negativity. The feeling will not stop, and beyond that, it dysregulates our sleep.2

Overall, the signs and symptoms demonstrate the inability to go through the daily routine, like paying attention at work, including personal projects. Furthermore, it would lead to severe disorders like bipolar personality disorders like DPD (dependent personality disorder) and BDP (borderline personality disorder).2

Seasonal patterns

Now that we have listed the depression and SAD symptoms, let’s explore the seasonal patterns. The winter pattern starts in early winter and then lifts off during the sunniest day.3

SAD in winter means that sleeping times are long as the period is at its coldest. During this period, we crave high carbohydrates, are prone to gaining weight, along with low mood.3 

However, in the summer season, it disturbs profound sleep as it will get hot while having negative feelings that make it impossible to ease the mind. 

Less appetite causes us to lose body weight. Agitation and an increase in irritability are the outcomes of losing weight quickly while the weather is hot.3

Differences from MDD

Seasonal affective disorder is associated with major depression disorder. SAD is diagnosed with depression disorder as a subplayer. In addition, seasonal affective disorder and major depression disorder together cause a shift in mood and are more common in young adults.4 

The symptoms of SAD and MDD are parallel; they both express depressive disorder and loss of interest, but the depression will get worse when the seasons arrive. 

Thus, the treatment approach has the same guidelines in using anti-depressant and cognitive behavioral therapy (CBT).4

Nevertheless, seasonal depression does not mean that the individual would not have depression tendencies; it is just that the depression gets worse during climate change.4

Causes of SAD

The experts are not clear on what causes SAD, but the main source is depression. There is guidance on factors that could trigger the worse side of depression. 

Role of reduced sunlight

The light is a factor that could ease SAD depression. Less light on the back of the eye alters the brain chemicals, preventing you from controlling your sleeping pattern, appetite, and changes in body temperature, and your mood regulator is disturbed.5

The effect of light depends on the exposure received and on the criteria assessed for diagnosis.1

Circadian rhythm disruption

Circadian rhythm disruption is a failure in the cycle of sleeping. There is such a thing as the inner body clock that is disrupted due to depression, having less focus on work and having self-esteem issues.5

Circadian rhythm disruption causes a delay in the sleeping cycle, which adds to SAD winter depression.

The bright light and low melatonin, a hormone released from the brain to time the sleeping cycle, indicates a misalignment encouraging circadian rhythm disruption, then progresses to experience SAD.6

The circadian rhythm sleep disorder includes depression, which is a factor contributing to SAD.5

Genetic and environmental factors

SAD is associated with genetics. The genetic factor is unpredictable to intervene if an individual develops depressive symptoms. Some individuals may be immune to the gene depression.7

A genetic variant is an altered DNA due to an unknown cause. A study conducted in 2018 shows that gene variant triggers and influences conduction like depression.7

The discussion gathers the thinking that changes in genetics can contribute to suffering from SAD and depression.7

Genetic factors may get in the way of the medication where absorption causes an impact on being ineffective.7 

Neurotransmitter imbalances

The brain chemistry dysregulation is what triggers SAD depression. Neurotransmitters are signals that communicate the mood between each brain cell. The signals produce serotonin hormone to regulate the mood, and other medications do incorporate antidepressants such as Prozac.8   

Neurotransmitters are the principal factors that induce depression to be out of control. 

Depression is caused by a chemical imbalance, which is still under investigation to provide evidence. However, there are different types of antidepressants that adhere to the neurotransmitters for the medication to be efficient.8

Depression medication should be tailored to the neurotransmitters and supervise the progress.8

The impact on neurotransmitters leads to fewer receptors to receive the neurotransmitter's signal, and there are not enough new neurotransmitters to stimulate. Thus, low serotonin production encourages depression and, furthermore, SAD.8

Relationship between SAD and depression

Depression is a beginning factor that later stabilises into a season where the depression feelings, signs and sad symptoms get worse in either winter or summer. 

Overlapping symptoms

The symptoms of SAD are not far off the depression symptoms. The two symptoms are gathered into one; Mayo Clinics explain in more detail that depression symptoms overlap with being irritable, frustrated, not getting proper sleep, unstable in weight and anxious are the symptoms that coincide with SAD symptoms.9 

Neurobiological mechanisms

The neurobiological mechanism resumes in the collapsing of the neurotransmitters, inducing the structure of the brain's sustainability.10

Neuroinflammation is an inflammatory reaction towards brain signal failing and then HPA axis dysfunction.10

The hypothalamic-pituitary-adrenal (HPA) axis balances the hormone when stressed. The outcome triggers neurogenesis and neuroplasticity.10

Neuroplasticity normally adapts to stress, but depression causes neuroplasticity to dysfunction and encourages imbalance in negative stimuli; thus, depression persists.11

Neurogenesis's function is to produce and promote new neurons. However, it is disturbing the production of new neurons. The outcome shows that the stress and mood are irregular.12

Risk factors for depression

There are certain factors that influence depression traits to be dominant when depression is associated with an individual’s personality and low self-esteem.9

Any situation that increases and feeds anxiety stress can then be worse as physical and mental abuse forces more complications.9 

Risk factors such as bipolar disorder, alcoholism and suicide if the depression escalates.9

Importance of diagnosis and treatment

SAD needs to be diagnosed as the disorder is predictable, correlating with either the winter blues or summer. SAD diagnosis is similar to depression but as the season fluctuates the spike of depression, it means that treatment preparation can facilitate SAD symptoms and prevent further complications.1 

The timing seems to be important to get the right support from the helpline and get the right treatment, hopefully not affecting brain chemistry or interfering with neurotransmitters.1

Diagnosis and treatment of SAD and depression

The first action to take is to be diagnosed, as it is in the best interest to not be misdiagnosed. Taking an appointment with your GP is advised. The GP will assess your symptoms and characterise your mental health state to decide and provide support. 

Diagnostic criteria

The criteria are to decide on the type of depression according to the National Institute of Health and Care Excellence (NICE). NICE guidelines will be followed by the GP to assure the right practice of diagnosing is valid. Following NICE would ensure the right to proper medication and therapies.1

The guidelines website shows all the disorders, including depression. For instance, assessment follow-ups, new treatment for first episodes, preventing relapse, possible disorders associated and which patients are prone to the diagnosis.1

Screening and assessment tools

Talking therapy is recommended after being diagnosed with SAD and depression by NICE. The NHS can provide proper counselling and medication followed by talking therapy.1

Cognitive-behavioral therapy (CBT) is the popular choice for SAD. CBT’s approach analyses how the individual thinks versus the things they do.

 CBT encourages SAD individuals to talk about their current situation instead of traditional therapy. The therapy session needs to be constant even if the individual is feeling better.1

Light therapy is better suited for winter depression. The therapy session is set up with a device that emits bright white and blue lights. The light increases of melatonin to promote sleeping as well as serotonin hormone to balance the mood.1

Evidence-based treatments

The treatment to manage the SAD winter or summer depression is through antidepressant medication. The medication would work best when the seasonal spike approaches as the depression’s symptoms are dominant.3

Mayo Clinic identifies Wellbutrin XL, and its splendid response can ease depression episodes.  These medications should be taken to prevent the upcoming waves of depression.3

Despite the drug medication, vitamin D sunlight exposure is an alternative way; it has been established that light exposure on the back of the eye can promote melatonin and serotonin hormones to stabilise mood disorders.3  

Importance of psychoeducation and lifestyle changes

Psychotherapy is also another talking therapy specific to SAD. During the therapy sessions, the expert will work on avoidance behaviour to cope. For instance, he is verbally pronouncing negative thoughts and learning to reduce anxiety.3

The method is to build and set a new foundation on healthy behaviour and combining physical exercise in order to sleep.3


In short, depression is the main symptom of seasonal affective disorder. SAD depression will fluctuate according to a season whether winter or summer, the weather can influence when it comes to our mood. Belief in light therapy and sunlight exposure (vitamin D) received on the back of the eye can ease the disorder. 

Before SAD depression gets worse, getting a proper diagnosis is important to accepting the disorder, preparing medications and having a support system. 


  1. Seasonal affective disorder [Internet]. seasonal affective diorder.Available from:
  2. Depression [Internet]. Depression . Mind; Available from:
  3. Seasonal affective disorder (Sad) - Symptoms and causes [Internet]. Mayo Clinic. [cited 2023 May 8]. Available from:
  4. How to tell the difference between seasonal affective disorder and depression [Internet]. Rogers Behavioral Health. [cited 2023 May 8]. Available from:
  5. Circadian rhythm sleep disorders: types, symptoms and management [Internet]. Cleveland Clinic. [cited 2023 May 8]. Available from:
  6. Lewy AJ, Emens JS, Songer JB, Sims N, Laurie AL, Fiala SC, et al. Winter Depression: Integrating mood, circadian rhythms, and the sleep/wake and light/dark cycles into a bio-psycho-social-environmental model. Sleep Med Clin [Internet]. 2009 Jun 1 [cited 2023 May 8];4(2):285–99. Available from:
  7. How genetics can play a role in depression [Internet]. Verywell Mind. [cited 2023 May 8]. Available from:
  8. What is the chemistry behind depression? [Internet]. Verywell Mind. [cited 2023 May 8]. Available from:
  9. Depression (Major depressive disorder) - Symptoms and causes [Internet]. Mayo Clinic. [cited 2023 May 8]. Available from:
  10. Neurobiology of depression - a simplified guide [Internet]. Psych Scene Hub. 2023 [cited 2023 May 8]. Available from:
  11. Liu W, Ge T, Leng Y, Pan Z, Fan J, Yang W, et al. The role of neural plasticity in depression: from hippocampus to prefrontal cortex. Neural Plasticity [Internet]. 2017 Jan 26 [cited 2023 May 8];2017:e6871089. Available from:
  12. Miller B, Hen R. The current state of the neurogenic theory of depression and anxiety. Current Opinion in Neurobiology. 2015;30:51–8.
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Suruthy Mary Joseph

Bachelor in Biomedical Science (IBMS)- BSc in University of Portsmouth

Suruthy has established 10 years of education in medical science and provides a strong writing background in advanced medical research. Suruthy undertook projects of her own and succeeded in Biomedical data. She is still eager to research and undercover clinical trials to educate the general public on various health problems and benefits. She incorporates her knowledge of traditional natural remedies in her research and writing. She is currently writing essays on various diseases at Klarity. presents all health information in line with our terms and conditions. It is essential to understand that the medical information available on our platform is not intended to substitute the relationship between a patient and their physician or doctor, as well as any medical guidance they offer. Always consult with a healthcare professional before making any decisions based on the information found on our website.
Klarity is a citizen-centric health data management platform that enables citizens to securely access, control and share their own health data. Klarity Health Library aims to provide clear and evidence-based health and wellness related informative articles. 
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