Many antipsychotics are associated with weight gain and thus contribute to metabolic and endocrine derangements, including insulin resistance [12]. Valproate is also associated with weight gain, as well as polycystic ovary syndrome. This may be secondary to its inhibition of the cytochrome P450 enzymes, leading to increases in androgen concentration and decreases in sex hormone-binding globulin (SHBG). There may also be direct effects on ovarian production of androgens. Duration of valproate treatment and free testosterone levels have been found to be significantly associated, suggesting a possible cumulative effect of valproate on androgen production [12, 13].

In some women, sexual side effects , e.g., lowered libido and decreased signs of sexual arousal, can be seen with COC use, likely due to increases in SHBG which lower levels of serum-free testosterone. SSRI use may be associated with decreased libido as well. Several studies suggest a relationship between estrogen and serotonin transporter expression with the binding affinity of serotonin receptors being affected, thereby leading to a decrease in sexual desire and/or functioning [14].

The most serious adverse effect associated with COC use in the general population is increased risk of vascular thrombosis . Some studies have suggested that patients on antipsychotic drugs might also be at increased risk of venous thromboembolism, with patients on an atypical antipsychotic such as quetiapine being at the highest risk [15]. There does not seem to be an additive effect for patients on COC simultaneously with antipsychotic drugs, however [16].

Benefits may exist for COC use in patients with schizophrenia as there are postulated positive effects of estrogen on cognitive functioning. Women with schizophrenia tend to present later than men, which is felt to be due to a protective effect of estrogen. Further, women may have more severe symptoms of schizophrenia during low-estrogen phases of their menstrual cycle. This has led to investigations using estrogen as a therapeutic agent for schizophrenia itself [17]. However, this may be less relevant in younger patients.

Drawbacks to the use of COC in patients with significant mental health issues might include difficulty with compliance, particularly during times of exacerbation of psychiatric symptoms. Patients may have distortions of risk around contraception or may have a belief that they are unable to become pregnant on their psychotropic medications [18]. Furthermore, symptoms of stress and depression, substance abuse, and impulsivity may all lead to a high rate of unprotected intercourse and subsequent risk for unintended pregnancy if inconsistently compliant with COC.

If adolescents and young women with depression or bipolar disorder are not being effectively contracepted, there are also concerns for the teratogenicity of certain medications used in treatment. One such medication, valproate , has been associated with major malformations, including neural tube defects, long-term adverse neurocognitive effects, and cardiac abnormalities. However, a recent retrospective review showed that only 30% of reproductive-age females who were prescribed valproate for a mental health disorder were on any form of hormonal contraception and provider counseling regarding teratogenicity of valproate was documented in only 13% of potentially affected patients [19]. Other medications used in mental health treatment which may be associated with major congenital malformations include lithium and carbamazepine, which can cause cardiac defects, and benzodiazepines, which may be linked to an increased incidence of cleft lip or palate [20]. Counseling regarding LARC, e.g., intrauterine devices and contraceptive implants, as a more reliable alternative option for pregnancy prevention, would be advised in patients for whom COC compliance is difficult [4, 5].

When counseling the adolescent patient with a mental health disorder about contraception, there may be individual factors around patient beliefs, goals, and preferences that impact decisions around contraceptive method choice. It is important to note that there may be significant interactions between certain psychotropic medications and hormonal methods of contraception (Table 21.2). LARC methods , which include the intrauterine device and the implantable rod, are increasingly being used by adolescent females in the US [21]. As LARC offers highly effective birth control without the need for frequent personal attention or health visits, these methods may be optimal for patients with mental health disorders that may interfere with medication compliance. Certainly, imparting the most accurate information around potential risks, benefits, and side effects of all options to patients on psychotropic medications allows for an informed patient choice.