Why Am I Depressed?

If you often have low moods, lack energy, and lose interest in your daily activities and hobbies, you may wonder, "Why am I depressed?" Experts do not exactly know what causes depression, though it's one of the most common mental health conditions. Research has identified several possible causes and risk factors, including genetics, seasonal changes, and stress. 

About one in six adults in the United States have depression in their lifetime. Understanding your depression risk can help you take steps to find support and treatment. Read on to learn possible depression causes and risk factors and how and when to seek help. 

Brain Chemistry

Your brain has chemicals, or neurotransmitters, that tell your body how to function. Your mood may change if two neurotransmitters, dopamine or serotonin, are too high or too low.

For example, dopamine helps you feel motivated and rewarded. A study published in 2016 found that dopamine dysfunction causes depressive symptoms like losing interest and motivation. The cause of that imbalance varies from person to person. Still, the researchers pointed out that stress and trauma trigger dopamine dysfunction.  

Researchers do not understand the link between depression and serotonin entirely. Serotonin helps you process emotions that affect your mood. Low serotonin levels do not appear to cause depression, but increasing serotonin levels can be an effective way to treat depression.

As a result, healthcare providers commonly treat depression with medicines that impact those brain chemicals, such as serotonin-norepinephrine reuptake inhibitors (SNRIs) or selective serotonin reuptake inhibitors (SSRIs).

Menstruation

Some people who menstruate have premenstrual dysphoric disorder (PMDD), which causes severe premenstrual syndrome (PMS) symptoms. Some people with PMDD have depression symptoms, including low mood during the week or two before their period.

PMDD may cause physical symptoms like:

• Bloating
• Breast tenderness
• Cramps
• Headaches

People with depression are more likely to have PMDD than others. Changing hormones during your menstrual cycle may disrupt serotonin levels, which may cause depression. 

A healthcare provider may suggest antidepressants, hormonal birth control, or therapy to treat PMDD.

Nutritional Deficiencies

An imbalanced diet can affect anyone's mood, but some evidence suggests that people with depression often have nutritional deficiencies.

For example, research has linked depression symptoms to a lack of nutrients, such as:

• B vitamins
• Magnesium
• Omega-3 fatty acids
• Zinc

Those nutrients help aid or create brain chemicals necessary for healthy brain function. For example, omega-3s aid in serotonin neurotransmission and help your brain process emotional behavior. Research has found that omega-3s may treat some cases of depression.

Still, there's not enough evidence showing how diet may cause depression. Speak with a healthcare provider or pharmacist before starting any supplements.

Pregnancy

Pregnancy causes emotional and physical demands, hormonal shifts, and stress, all of which may lead to perinatal depression. You may have perinatal depression during pregnancy (prenatal depression) and after childbirth (postpartum depression). 

Depression can make caring for yourself and others challenging. Treatment with medication, therapy, or a combination of both can often make you feel better.  

Seasonal Changes

Seasonal changes during the fall and winter months, when the days are shorter than in the spring and summer months, may lead to seasonal affective disorder (SAD). A lack of sunlight exposure may alter your circadian rhythm, which regulates hormones and other body functions related to mood.  

A healthcare provider may advise light therapy to treat SAD. Some people with SAD notice their depression symptoms typically improve during the spring and summer months.

Thyroid Disorders

A healthcare provider may check that your thyroid is properly functioning if you have depression symptoms. Your thyroid is a butterfly-shaped gland in your neck that creates hormones that affect many functions in your body, including your mood. Research has linked hypothyroidism, which causes low levels of thyroid hormones, to depression symptoms.

Other underactive thyroid symptoms include:

• Cold sensitivity
• Dry hair or skin 
• Fatigue
• Joint and muscle pain

Medications that help replace thyroid hormones may manage depression symptoms if hypothyroidism is the cause.

Is Depression Hereditary?

People who have family members with depression are more likely to develop the mental health condition than others. A family history of perinatal depression may increase your risk of depression during or after pregnancy. Having had depression yourself at one point increases your risk for depression later in life.

Some evidence suggests that people with depression may have genetic variants predisposing them to it. Those variants may cause changes in brain chemistry related to depression. Though, there's not enough evidence to support that link.

Who Gets Depression?

According to data from the National Institute of Mental Health (NIMH) collected among adults older than 18 in the United States, some people are more likely to develop depression than others, such as:

• Age: Rates of depression are highest among people aged 18–25, with 18.6% affected.
• Ethnicity: People who identify with two or more ethnicities are more likely to have depression than others. Interpersonal and structural racism drives inequities that increase the risk of poor health outcomes among ethnic minority groups.
• Sex: The NIMH reports that 10.3% of people assigned female at birth have depression, compared to 6.2% of people assigned male at birth.

Research has found that ethnic minority groups are more likely to have long-lasting, severe depression symptoms than White people. A study published in 2019 noted that ethnic minority groups are often underrepresented in data due to underdiagnoses. Ethnic minority groups may face barriers to mental healthcare services, often due to factors like cost and stigma.

Risk Factors

Certain environmental factors and life experiences may increase your risk of depression, especially if you are already at risk due to other genetic or health factors. These risk factors do not necessarily cause depression but can trigger symptoms in some people. 

Adverse Childhood Experiences

Childhood plays a vital role in developing your brain and personality. Research has found that severe early childhood stress, such as abuse, can fundamentally change brain function and lead to severe depression later in life.

Medications

Some prescription medications alter levels of brain chemicals that help regulate mood. For example, medicines that treat chronic migraine, heart problems, Parkinson's disease, and seizure disorders may result in depression symptoms. Talk to a healthcare provider if you take medications that may impact your mood.

Sleep Deprivation

A bad night's sleep can zap your mood, and a long-term lack of sleep can affect mental health. Research has found that people with insomnia are more likely to develop depression than those who regularly get enough sleep. Sleep changes, especially trouble sleeping, are common with depression and may worsen symptoms.

Stress

Depression may stem from negative thinking patterns related to stressful situations, like:

• Being part of a marginalized community 
• Feeling isolated
• Going through events like breakups, grief, loss, and major transitions
• Having a chronic illness, especially later during adulthood

People with an anxiety disorder or obsessive-compulsive disorder (OCD) may be at risk for depression. Anxiety disorders typically involve prolonged stress that impacts your daily activities. OCD causes intrusive thoughts (obsessions), which may lead to certain behaviors (compulsions). For example, an obsession may be a fear of germs, while the compulsion may be to wash your hands excessively.

Some evidence suggests that people with an anxiety disorder or OCD may be likelier to develop depression than others. Depression symptoms may occur as a result of feeling helpless or hopeless in managing their negative thoughts and stress.

Cognitive behavioral therapy (CBT) and psychotherapy can help people manage stress, anxiety disorders, and OCD by thinking differently about difficult circumstances. For example, CBT may include behavioral activation, a technique that encourages you to partake in activities that improve your mood. Examples may include gardening or socializing with your friends.

Substance Use Disorders

Research has linked alcohol use disorder (AUD) to depression. Alcohol is a depressant that slows body functions, including how your body balances brain chemicals like dopamine and serotonin. Some people may self-medicate their low mood by drinking, worsening depression symptoms.

Some evidence suggests that people who smoke cigarettes are more likely to become depressed than others. Still, researchers do not know the exact reason.

A Quick Review

Several environmental, genetic, and health factors related to brain chemicals and hormones may cause depression. You may seek help if you constantly feel hopeless and sad, interfering with your daily activities. 

Speak with a healthcare provider if you think you may have depression. They may refer you to a mental health specialist. It can feel vulnerable to admit you are struggling and ask for help. Still, several effective treatments can help improve your quality of life.