The use of birth control pills, oral contraceptives, to help prevent pregnancy is widespread. Oral contraceptives contain progestin or synthetic progesterone. These contraceptives have several negative side effects, including physical and emotional changes, according to a review of research in the February 2004 issue of “Medical Hypotheses.” A depressed mood may be one such side effect in some women 3.

Depression, Mood and Affect

People with depression feel sad, blue or down in the dumps; however, depression is more than these feelings, according to the American Psychiatric Association. Mood refers to a constant or sustained emotion; whereas, affect is a state of feeling at a given moment in time. A person with depression would have a flattened mood over a period of time, though the person’s affect may vary, such that the person may seem more happy or sad at times.

Oral Contraception Use on Mood and Affect

Research findings about oral contraceptive use on mood is mixed. Some studies found increased depression among oral contraceptive users, some found decreased rates and a few had no relationships between oral contraceptive use and mood, according to a review of research in the August 2002 edition of the “Journal of Affective Disorders.” Oral contraceptive users experienced less affect changes across the entire menstrual cycle in comparison to women not taking oral contraceptives, according to the article 2.

Risk Factors

Some women taking oral contraceptives experience changes in mood and affect 2. Kirsten Oinonen, Ph.D., et. al; August 2002'). The amount of progesterone in comparison to estrogen may also play a factor. Less progesterone and more estrogen is associated with greater depressed mood in women with a history of having premenstrual sadness. For women without a history of premenstrual sadness, a higher level of progesterone in comparison to estrogen is related to negative mood changes.

How Oral Contraceptives Affect Mood and Affect

Researchers are studying physiological ways oral contraceptives may influence mood and affect and several mechanisms have been suggested, according to the “Journal of Affective Disorders” article 2. One possible way involves the effects of the hormones progesterone and estrogen on the neurotransmitter GABA. Progesterone and estrogen may increase the tendency for GABA to suppress glutamate, which is a neurotransmitter involved with mood. Another mechanism involves the effects of progesterone on monoamine oxidase, MAO, an enzyme that influences neurotransmitters. Progesterone may cause MAO to lower levels of the neurotransmitter serotonin, which may lead to depression.