Teen depression signs and symptoms include a change from the teenager's previous attitude and behavior that can cause significant distress and problems at school or home, in social activities, or in other areas of life.

Depression symptoms can vary in severity, but changes in your teen's emotions and behavior may include the examples below.

Emotional changes

Be alert for emotional changes, such as:

• Feelings of sadness, which can include crying spells for no apparent reason
• Frustration or feelings of anger, even over small matters
• Feeling hopeless or empty
• Irritable or annoyed mood
• Loss of interest or pleasure in usual activities
• Loss of interest in, or conflict with, family and friends
• Low self-esteem
• Feelings of worthlessness or guilt
• Fixation on past failures or exaggerated self-blame or self-criticism
• Extreme sensitivity to rejection or failure, and the need for excessive reassurance
• Trouble thinking, concentrating, making decisions and remembering things
• Ongoing sense that life and the future are grim and bleak
• Frequent thoughts of death, dying or suicide

Behavioral changes

Watch for changes in behavior, such as:

• Tiredness and loss of energy
• Insomnia or sleeping too much
• Changes in appetite — decreased appetite and weight loss, or increased cravings for food and weight gain
• Use of alcohol or drugs
• Agitation or restlessness — for example, pacing, hand-wringing or an inability to sit still
• Slowed thinking, speaking or body movements
• Frequent complaints of unexplained body aches and headaches, which may include frequent visits to the school nurse
• Social isolation
• Poor school performance or frequent absences from school
• Less attention to personal hygiene or appearance
• Angry outbursts, disruptive or risky behavior, or other acting-out behaviors
• Self-harm — for example, cutting, burning, or excessive piercing or tattooing
• Making a suicide plan or a suicide attempt

It's not known exactly what causes depression, but a variety of issues may be involved. These include:

• Brain chemistry. Neurotransmitters are naturally occurring brain chemicals that carry signals to other parts of your brain and body. When these chemicals are abnormal or impaired, the function of nerve receptors and nerve systems changes, leading to depression.
• Hormones. Changes in the body's balance of hormones may be involved in causing or triggering depression.
• Inherited traits. Depression is more common in people whose blood relatives — such as a parent or grandparent — also have the condition.
• Early childhood trauma. Traumatic events during childhood, such as physical or emotional abuse, or loss of a parent, may cause changes in the brain that make a person more susceptible to depression.
• Learned patterns of negative thinking. Teen depression may be linked to learning to feel helpless — rather than learning to feel capable of finding solutions for life's challenges.

Many factors increase the risk of developing or triggering teen depression, including:

• Having issues that negatively impact self-esteem, such as obesity, peer problems, long-term bullying or academic problems
• Having been the victim or witness of violence, such as physical or sexual abuse
• Having other mental health conditions, such as bipolar disorder, an anxiety disorder, a personality disorder, anorexia or bulimia
• Having a learning disability or attention-deficit/hyperactivity disorder (ADHD)
• Having ongoing pain or a chronic physical illness such as cancer, diabetes or asthma
• Having certain personality traits, such as low self-esteem or being overly dependent, self-critical or pessimistic
• Abusing alcohol, nicotine or other drugs
• Being gay, lesbian, bisexual or transgender in an unsupportive environment

Family history and issues with family or others may also increase your teenager's risk of depression, such as:

• Having a parent, grandparent or other blood relative with depression, bipolar disorder or alcohol use problems
• Having a family member who died by suicide
• Having a dysfunctional family and family conflict
• Having experienced recent stressful life events, such as parental divorce, parental military service or the death of a loved one

Untreated depression can result in emotional, behavioral and health problems that affect every area of your teenager's life. Complications related to teen depression may include, for example:

• Alcohol and drug misuse
• Academic problems
• Family conflicts and relationship difficulties
• Involvement with the juvenile justice system
• Suicide attempts or suicide