If heat, sunshine, and tons of free time leave you feeling low, you could have summer depression

• Summer depression, a type of major depression, begins in summer and improves as the weather cools.
• Experts believe causes include high pollen, increased heat and sunlight, and changes in routine.

You've likely heard of the winter blues, but did you know some people experience significant mood changes when summer rolls around?

This type of seasonal affective disorder (SAD) is often called summer depression. While SAD is more common in the wintertime, when days are shorter and darker, it can set in any time of year.

Summer depression typically occurs between late May or June and late September.

Note: Some people experience spring depression, which involves similar symptoms as summer depression but generally begins around March and ends by June.

Here's what to know about the signs, causes, and common treatments for summer depression.

Signs and symptoms

Many summer depression symptoms tend to involve the opposite of winter depression symptoms. For example, while winter depression often causes oversleeping, summer depression may cause trouble falling or staying asleep.

Here are some other common signs to pay attention to as the hotter months approach, according to Rachel Cavallaro, a licensed psychologist with Thriveworks.

• Decreased appetite and unintentional weight loss
• Agitation or restlessness
• Difficulty focusing
• Irritability
• Loss of interest in activities
• Social avoidance
• Decreased interest in sex

Cavallaro says these symptoms usually start as soon as you begin to feel seasonal changes — often around May, or as the days get longer and the weather gets warmer — and resolve by fall.

What causes it?

About 5% of US adults experience SAD, and only about 10% of that group have summer depression, according to Cavallaro.

Research also suggests SAD occurs four times more often in women than men.

Notable risk factors for summer depression include:

• Living in an area with distinct seasons
• Having another mood disorder, like bipolar disorder or major depression
• Having a family history of depression or SAD

Research on summer depression remains limited, but experts have come up with a few theories to help explain why this condition develops.

Increased sunlight exposure

According to Dr. Mary Kaland, a licensed psychiatrist with Lehigh Valley Health Network, an increase in sunlight can disrupt your circadian rhythms — your body's natural internal clock that regulates your sleep-wake cycle.

As a result, you may find it harder to get adequate sleep, which can then negatively affect your mood.

Seasonal allergies

Kaland says the increases in pollen during the early summer may take a toll on your mood if you have seasonal allergies.

In fact, a 2019 study of Amish adults — who experience high pollen and sunlight exposure during the summer months — found that participants reported worse mood symptoms on days with surging pollen counts.

Lack of routine

Routines offer a sense of predictability and accomplishment and can add meaning to your life.

According to a 2021 study of Chinese college students, those who reported more family routines in childhood had a lower risk of depression symptoms in adulthood.

Yet summertime can disrupt your daily routine, leaving vast expanses of unstructured time. This is especially true for students, teachers, and people who travel a lot during the summer.

Dr. Jeff Ditzell, a licensed psychiatrist in private practice, says this lack of structure can allow more time for anxious rumination, which can contribute to depression.

Increased heat and humidity

Summertime means increased heat and humidity, which can bring discomfort for a lot of people. Not only that, but the summer heat can leave you fatigued and energy depleted, feelings often linked to depression.

If you find the heat particularly intolerable, you may even skip depression-busting activities you'd normally enjoy, Cavallaro says, like social outings or exercise.

Body image issues

As the temperatures rise, many people swap their pants and sweaters for tank tops, shorts, and swimsuits. If you experience body-related insecurities, this can cause significant distress, Cavallaro says.

You might, then, end up skipping social events to avoid being seen in warm-weather clothes, which can then further your feelings of isolation or loneliness.

Additionally, Cavallaro says seeing people on social media showing off more skin may deepen insecurities by triggering comparisons and negative self-talk. If you think your poor body image is causing or worsening your depression, Chedd suggests limiting your time on social media and engaging in daily positive self-talk.

Financial stressors

Ditzell says summer can often trigger money-related worries for business owners who face a slowdown in sales.

Knowing you can't afford to take a vacation or send your child to daycare could also prompt feelings of depression.

Moreover, if you rely on school lunches to feed your children, you may also feel anxious or depressed as you try to ensure they're well nourished during the summer.

Unmet high expectations

"People are bombarded with summertime ads about people having an amazing time at resorts, on cruises, and amusement parks, and they may not have access to those experiences," says Naomi Angoff Chedd, a licensed mental health counselor and Clinical Director at Counslr.

"Even if they do, they may feel let down, because not every experience is all it's cracked up to be," Chedd says — this disappointment can then trigger feelings of guilt about how grateful, excited, or happy you "should" feel, often worsening feelings of depression.

Getting a diagnosis

The actual diagnosis for summer depression is major depressive disorder (MDD) with a seasonal pattern, according to Cavallaro.

Here's the criteria for a diagnosis:

• A pattern of depression that begins and ends at a specific time every year.
• Symptoms that return for at least two years, with no nonseasonal episodes of depression.
• Having more seasons of depression than seasons without depression over your lifetime.

If you already have a diagnosis of MDD, a trained mental health professional can adjust your diagnosis to MDD with a seasonal pattern. Kaland says it's a matter of determining whether your symptoms become different, more frequent, or more intense in the summer.

Potential treatments

You don't need to face the summer months with dread each year. These strategies can help improve symptoms and boost your mood:

Cognitive behavioral therapy (CBT)

Cavallaro says CBT is one of the most effective types of therapy for depression.

CBT aims to increase your awareness of negative thought patterns that can lower your mood and emotional state. A therapist trained in CBT can help you work to identify and address any anxious, self-critical, or otherwise unhelpful thoughts you experience.

Important: Many experts consider CBT the gold standard treatment for depression and other mental health conditions — but not everyone finds CBT helpful. Alternate approaches include interpersonal therapy, psychodynamic therapy, mindfulness-based cognitive therapy, and acceptance and commitment therapy.

Best online therapy providers

• Best for full access to a self-selected therapist: BetterHelp, from $60 per week
• Best for limited access to an assigned therapist, covered by insurance: TalkSpace, from $65 per week
• Best for cheap online therapy and self-guided work: Online-Therapy.com, from $31.96 per week

Medication

Your primary care physician or psychiatrist may try prescribing you an antidepressant for severe summer depression, with the most common medication being selective serotonin reuptake inhibitors (SSRIs).

Antidepressants like SSRIs can improve symptoms like fatigue and low mood, and you may start to regain your interest in the things you usually enjoy. That said, they can't address depression causes or triggers.

According to Cavallaro, these medications tend to be far more effective when combined with therapy.

It can take up to six to eight weeks to notice an improvement in symptoms with these medications, so your doctor may decide to prescribe them a month or two before summer starts.

Other coping mechanisms may include:

• Establishing a routine: Sticking to a schedule means you know what to expect each day, which may help ease anxious thoughts or a sense of purposelessness. You might, for instance, start your day by meditating, making breakfast, and checking emails. In the afternoons, you might set aside time for a hobby. At night, Cavallaro recommends winding down and putting away blue light-emitting devices about an hour before bed.
• Taking care of your body: Chedd recommends a regular sleep schedule, nutritious meals, and adequate exercise if you're able. Exercise can contribute to feelings of competence and confidence, boost your self-image, take your mind off negative thoughts, and release mood-boosting chemicals in your brain, Chedd says.
• Staying connected: Staying in touch with loved ones and planning regular check-in times or hangouts can help you avoid feeling lonely or isolated during the summer. It can also help you get support with managing symptoms of depression.
• Journaling: Writing down the feelings you experience can contribute to deeper self-awareness and a sense of taking control of your life, Chedd says. Also, journaling can help you keep track of depression symptoms and make it easier to notice patterns, like when they tend to worsen or improve.
• Mindfulness meditation: "Mindfulness meditation helps you objectively observe your thoughts and feelings so you can be less reactive to them. By focusing on your breath, you can reduce feelings of stress in the body," Cavallaro says.

Insider's takeaway

Though research on the causes of summer depression remains limited, experts believe it can stem from a wide range of factors, such as drastic changes in routine, seasonal allergies, and sleep difficulties related to increased sun exposure.

Although summer depression may not be as common as winter depression, it can have a similar impact on your overall health and quality of life. Ultimately, the best treatment generally depends on the cause. Support from a trained mental health professional can help you determine key triggers and explore helpful treatments.

For example, if you think your poor body image is the cause, Chedd suggests taking a break from or limiting your time on social media and engaging in daily positive self-talk.

Above all, Chedd says it's important to remind yourself you're not alone, and your feelings aren't permanent — they can, and will, get better.