The Condition

Depressive disorders are a group of mood disorders that affect a person’s ability to perform daily functions, facilitated by persistent or episodic irritable, sad or vacant moods. Depression affects men and women of all ages; it can be disabling, interfere in daily activities, limit normal functioning, and potentially lead to suicide. Worldwide, it has been estimated 340 to 360 million people suffer from major depressive disorders with 18 million represented in the United States.⁸⁷ Depressive disorders occur more frequently in women, with prevalence rates approximately twice as high as those in men.⁸⁸ The sex difference in depressive disorder prevalence emerges during adolescence and is most pronounced in this life stage and through early adulthood. In 2021, depressive disorders were the sixth leading cause for disability-adjusted life years (DALYs), in women internationally. They did not rank among the top ten causes for men. In the United States, the burden is particularly significant among adolescents and young women aged 15-39, where depression ranks among the three leading causes of DALYs.⁸⁹

No single cause of depression has been identified; however, studies indicate combinations of factors are likely to exist. Since women are being diagnosed more than men, research is currently exploring factors associated with their increased risk for depression. Social, genetic, hormonal, biological and chemical factors unique to women are being examined as potential links to depression.⁸⁴

Depressive illnesses have been characterized as brain disorders; magnetic resonance imaging (MRI) has demonstrated brain matter in those with depression appear differently than in those where no depression has occurred.⁹⁰ Depression is a disorder of brain circuits, neurotransmitter signaling, and stress‑response systems, not simply a chemical shortage. In depressive disorders, neurotransmitter systems involved in neural communication, especially those regulating mood, motivation, sleep, and appetite, show disrupted signaling, leading to impaired functioning across the brain circuits that govern emotional and physiological regulation.⁹¹

Depressive episodes can last several months or up to one year depending on the individual’s family support system and access to treatment. Depression has been shown to influence subsequent episodes. Recurrent episodes can vary among women and years may lapse between occurrences; however, as women age the frequency of episodes tends to increase.⁹² Studies have indicated at least 60% of those suffering their first depressive episode will typically encounter a second and those experiencing two episodes will have a 70% chance to suffer a third.⁹³ One study focused on depression that precedes an onset of manifest bipolar disorder as early stage bipolar disorder. In a population cohort of 3012 young community participants, 3.6% of people with an initial depression were re-diagnosed with bipolar disorder after a period of up to 10 years.⁹⁴ The risk was substantially higher at 9% in those with onset of depression before the age of 17.

Adolescence is an important period of growth and development as well as a key risk period when the occurrence of depressive symptoms rises abruptly. During adolescence, sex differences emerge and widen noticeably with regard to emotional disorders, and we do not se these changes in childhood. Depressive symptoms are two to three times more prevalent in girls compared to boys during adolescence, and girls are also affected more seriously by depression.⁹⁵

Hormonal fluctuations during menstrual cycles, pregnancy, and menopause can significantly impact anxiety levels, making anxiety conditions more common and often more severe in women. Additionally, women have greater social pressures related to appearance, career, and family roles, which contribute to heightened stress and anxiety. There are different types of anxiety disorders, and a difference between anxiety as a normal response to threat or stress.⁹⁶ There are times when anxiety is a normal physical response to a perceived danger. Also, depressive symptoms often accompany anxiety disorder as a comorbidity. Anxiety symptoms occur on a continuum, and many people with mild symptoms of recent onset associated with stressful events or situations improve without needing any treatment. However, the chronic nature and associated disability of anxiety disorders means that most patients who fulfil diagnostic criteria are likely to benefit from treatment, whether this is psychological or pharmacological.⁹⁶