Seasonal Affective Disorder (SAD) and Hair Loss

Seasonal Affective Disorder (SAD) is sometimes dismissed off-hand by people who believe it is not a ‘real thing’. However, it is a mental health condition officially recognized by the NHS and affects thousands of people every winter. Dealing with depression is hard enough, but can SAD also lead to hair loss? Read on to find out more.

What is Seasonal Affective Disorder (SAD)?

Seasonal Affective Disorder (SAD) is a form of recurrent depression linked to seasonal change—most commonly triggered during autumn and winter when daylight hours decrease. Reduced light exposure disrupts circadian rhythm, serotonin regulation, and melatonin balance, all of which influence mood, energy, and cognitive function.

SAD is not simply “winter blues.” It is a clinically recognised depressive disorder with measurable psychological and physiological impact.

Common Symptoms of SAD

Individuals experiencing SAD may report:

Persistent low mood
Anhedonia (loss of interest in previously enjoyed activities)
Fatigue and reduced motivation
Sleep disturbance (insomnia or hypersomnia)
Appetite changes and weight fluctuation
Reduced concentration and increased irritability

Symptoms typically improve as daylight hours increase.

Can SAD Contribute to Hair Loss?

While SAD itself does not directly “cause” hair loss, the physiological stress associated with depression can disrupt the hair growth cycle.

Hair follows a structured cycle:

Anagen (growth phase) – 2 to 6 years
Catagen (transition phase)
Telogen (resting/shedding phase)

On average, individuals shed 50–100 hairs per day, which are normally replaced through continuous follicular activity.

However, psychological stress and mood disorders can trigger Telogen Effluvium, a condition in which a larger percentage of follicles prematurely enter the shedding phase. This results in noticeable thinning rather than isolated hair fall.

Seasonal Shedding: Is It Real?

Research suggests mild seasonal variation in hair density:

Increased hair growth activity during spring
Higher shedding rates during late summer and autumn

For individuals already experiencing SAD-related stress, this natural seasonal shift can compound visible thinning.

Seasonal Hair Loss

It wasn’t until a study was carried out at Washington University that scientists came across some interesting data. Looking at Google Trends collected between 2004 and 2016 from eight different English-speaking countries, they honed in on the search term ‘hair loss’.

They found that searches for the term peaked during the summer and autumn periods. They noticed that ‘hair loss’ was less commonly looked for during spring, suggesting it was less of a concern for people as the hair was not noticeably falling out during these months.

It is already known that animals molt at certain periods of the year and for humans, this is known as something called ‘seasonal shedding’. People dealing with mental health issues can sometimes see it manifest itself in their physical appearance. Whether it is weight loss, headaches, aches and pains or hair loss, the high levels of stress created by SAD can also lead to the shedding of hair.

What can I do about SAD-related hair loss?

If you are experiencing SAD you notice you are experiencing more hair loss than normal, there is a good chance the two could be related. SAD hair loss doesn’t mean you are losing your hair for good, it could be restored once the winter period has passed.

Of course, if you are struggling to cope with SAD and need assistance, you should visit your local doctor for advice to see if additional help is required and available. They will be able to offer professional guidance and direction on other resources that may be able to improve the condition of your mental health.

Although it can be very difficult if you are dealing with depressions during the winter months, or at other times of the year, it is important to speak about it and seek help, as suffering in silence can make matters worse in the long run.

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