Substance Use in Women Research Report
Sex and Gender Differences in Substance Use

Men are more likely than women to use almost all types of illicit drugs,¹³ and illicit drug use is more likely to result in emergency department visits or overdose deaths for men than for women. "Illicit" refers to use of illegal drugs, including marijuana (according to federal law) and misuse of prescription drugs. For most age groups, men have higher rates of use or dependence on illicit drugs and alcohol than do women.¹⁴ However, women are just as likely as men to develop a substance use disorder.¹⁵ In addition, women may be more susceptible to craving^16–19 and relapse,^20,21 which are key phases of the addiction cycle.

Illegal Drugs

Marijuana (Cannabis)

Similar to other addictive drugs, fewer females than males use marijuana.¹³ For females who do use marijuana, however, the effects can be different than for male users. Research indicates that marijuana impairs spatial memory in women more than it does in men,^22,23 while males show a greater marijuana-induced high.^24,25

In one study specific to teenagers, male high school students who smoke marijuana reported poor family relationships and problems at school more often than female students who smoke marijuana.²⁶ However, a few studies have suggested that teenage girls who use marijuana may have a higher risk of brain structural abnormalities associated with regular marijuana exposure than teenage boys.^27,28

Animal studies show that female rats are more sensitive to the rewarding,^29,30 pain-relieving,^31–33 and activity-altering^31,33,34 effects of marijuana's main active ingredient, delta-9-tetrahydrocannabinol (THC). Many of these differences have been attributed to the effects of sex hormones,^{29,31,35–37} although rodent research also points to the possibility that there are sex differences in the functioning of the endocannabinoid system, the system of brain signaling where THC and other cannabinoids exert their actions.^30,38

Marijuana Use Disorder

Men	Women
Similarities
At least one other mental health disorder Low rate of seeking treatment
Differences
Other substance use disorders Antisocial personality disorder Severity of disorder	Panic attacks Anxiety disorders Disorder develops more quickly

For both sexes, marijuana use disorder is associated with an increased risk of at least one other mental health condition, such as depression or anxiety. However, men who are addicted to marijuana have higher rates of other substance use problems as well as antisocial personality disorders. By contrast, women who are addicted to marijuana have more panic attacks³⁹ and anxiety disorders.^40,41 Although the severity of marijuana use disorders is generally higher for men, women tend to develop these disorders more quickly after their first marijuana use.⁴² Rates of seeking treatment for marijuana use disorder are low for both sexes.⁴³

Stimulants (Cocaine and Methamphetamine)

Research in both humans and animals suggests that women may be more vulnerable to the reinforcing (rewarding) effects of stimulants, with estrogen possibly being one factor for this increased sensitivity.^44–47 In animal studies, females are quicker to start taking cocaine—and take it in larger amounts—than males. Women may also be more sensitive than men to cocaine's effects on the heart and blood vessels. In contrast, female and male cocaine users show similar deficits in learning, concentration, and academic achievement, even if women had been using it longer. Female cocaine users are also less likely than male users to exhibit abnormalities of blood flow in the brain's frontal regions. These findings suggest a sex-related mechanism that may protect women from some of the detrimental effects of cocaine on the brain.⁴⁸

As for methamphetamine, women report using the drug because they believe it will increase energy and decrease exhaustion associated with work, home care, child care, and family responsibilities. Weight loss is another incentive women cite for methamphetamine use—and one reported significantly more by women than by men.^49,50 Women also report using methamphetamine because they believe it will increase energy and decrease exhaustion associated with work, home care, child care, and family responsibilities.^49,50 Women who use methamphetamine also have high rates of co-occurring depression.^51–54

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Source: Brecht et al., 2004

Women tend to begin using methamphetamine at an earlier age than do men,^50,51 with female users typically more dependent on methamphetamine compared to male users.^53,55 Women are also less likely to switch to another drug when they lack access to methamphetamine.⁵⁰ In addition, as with other substances, women tend to be more receptive than men to methamphetamine treatment.^51,54,56

MDMA (Ecstasy, Molly)

Research suggests that MDMA produces stronger hallucinatory effects in women compared to men, although men show higher MDMA-induced blood pressure increases.⁵⁷ There is some evidence that, in occasional users, women are more prone than men to feeling depressed a few days after they last used MDMA.⁵⁸ Both men and women show similar increases in aggression a few days after they stop using MDMA.^58,59

MDMA can interfere with the body's ability to eliminate water and decrease sodium levels in the blood, causing a person to drink large amounts of fluid. In rare cases, this can lead to increased water in the spaces between cells, which may eventually produce swelling of the brain and even death. Young women are more likely than men to die from this reaction, with almost all reported cases of death occurring in young females between the ages of 15 and 30.^60,61 MDMA can also interfere with temperature regulation and cause acute hyperthermia, leading to neurotoxic effects and even death.⁶²

Heroin

Compared with men, women who use heroin are:

• younger
• likely to use smaller amounts and for a shorter time
• less likely to inject the drug
• more influenced by drug-using sexual partners

Research suggests that women tend to use smaller amounts of heroin and for less time, and are less likely than men to inject it.⁶³ Most women who inject heroin point to social pressure and sexual partner encouragement as factors.^63–66 One study indicates that women are more at risk than men for overdose death during the first few years of injecting heroin, but it is unclear why this might be the case. One possibility is that women who inject heroin are more likely than their male counterparts to also use prescription drugs—a dangerous combination. Women who do not overdose within these first few years are more likely than men to survive in the long term. This could be due to differences in treatment and other environmental factors that impact heroin use.⁶⁷

Prescription Drugs

Prescription drug misuse is the use of a medication without a prescription, in a way other than as prescribed, or for the experience or feelings elicited. Prescription drug misuse can be dangerous if mixed together without a physician's guidance, or mixed with other drugs or alcohol.

Prescription Opioids

Some research indicates that women are more sensitive to pain than men⁶⁸ and more likely to have chronic pain,⁶⁹ which could contribute to the high rates of opioid prescriptions among women of reproductive age.⁷⁰ In addition, women may be more likely to take prescription opioids without a prescription to cope with pain, even when men and women report similar pain levels. Research also suggests that women are more likely to misuse prescription opioids to self-treat for other problems such as anxiety or tension.⁷¹

A possible consequence of prescription opioid misuse is fatal overdose, which can occur because opioids suppress breathing. In 2016, 7,109 women and 9,978 men died from prescription opioid overdose (a total of 17,087)* which is about 19 women per day compared to about 27 men dying from overdosing on prescription opioids. However, from 1999 to 2016, deaths from prescription opioid overdoses increased more rapidly for women (596 percent or sevenfold) than for men (312 percent or fourfold). Women between the ages of 45 and 54 are more likely than women of other age groups to die from a prescription opioid overdose.⁷²

*Note that in this instance, “prescription opioids” includes other opioids and methadone (ICD-10 codes T40.2-T40.3).

Anti-Anxiety Medications and Sleeping Aids

Women are more likely to seek treatment for misuse of central nervous system depressants,¹⁴ which include sedatives sometimes prescribed to treat seizures, sleep disorders, and anxiety, and to help people fall asleep prior to surgery. Women are also more likely than men to die from overdoses involving medications for mental health conditions, like antidepressants. Antidepressants and benzodiazepines (anti-anxiety or sleep drugs) send more women than men to emergency departments.⁷³ Because women are also more at risk than men for anxiety^74,75 and insomnia,⁷⁶ it is possible that women are being prescribed more of these types of medications; greater access can increase the risk of misuse and lead to substance use disorder or overdose.

Other Substances

Alcohol

In general, men have higher rates of alcohol use, including binge drinking. However, young adults are an exception: girls ages 12 to 20 have slightly higher rates of alcohol misuse and binge drinking than their male counterparts.¹³

Drinking over the long term is more likely to damage a woman's health than a man's, even if the woman has been drinking less alcohol or for a shorter length of time.^77,78 Comparing people with alcohol use disorders, women have death rates 50 to 100 percent higher than do men, including deaths from suicides, alcohol-related accidents, heart disease, stroke, and liver disease.⁷⁹ In addition, there are some health risks that are unique to female drinkers. For example, heavy drinking is associated with increased risk of having unprotected sex, resulting in pregnancy or disease,⁸⁰ and an increased risk of becoming a victim of violence and sexual assault. In addition, drinking as little as one drink per day is associated with a higher risk of breast cancer in some women, especially those who are postmenopausal or have a family history of breast cancer.⁷⁹

In addition, men and women metabolize alcohol differently due to differences in gastric tissue activity. In fact, after drinking comparable amounts of alcohol, women have higher blood ethanol concentrations.^79,81–83 As a result, women become intoxicated from smaller quantities of alcohol than men.⁸²

More information on sex and gender differences in alcohol use is available from the National Institute of Alcohol Abuse and Alcoholism (NIAAA).

Nicotine (Tobacco)

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Source: CDC, 2014

Research indicates that men and women differ in their smoking behaviors. For instance, women smoke fewer cigarettes per day, tend to use cigarettes with lower nicotine content, and do not inhale as deeply as men.⁸⁴ Women also may smoke for different reasons than men, including regulation of mood and stress.⁸⁵ It is unclear whether these differences in smoking behaviors are because women are more sensitive to nicotine, because they find the sensations associated with smoking less rewarding, or because of social factors contributing to the difference; some research also suggests women may experience more stress and anxiety as a result of nicotine withdrawal than men.⁸⁶

Risk of death from smoking-associated lung cancer, chronic obstructive pulmonary disease, heart disease, and stroke continues to increase among women—approaching rates for men.⁸⁷ According to data collected from 2005 to 2009, approximately 201,000 women die each year due to factors related to smoking—compared to about 278,000 men.⁸⁸ Some dangers associated with smoking—such as blood clots, heart attack, or stroke—increase in women using oral contraceptives.⁸⁹

The number of smokers in the United States declined in the 1970s and 1980s, remained relatively stable throughout the 1990s, and declined further through the early 2000s. Because this decline in smoking was greater among men than women, the prevalence of smoking is only slightly higher for men today than it is for women. Several factors appear to be contributing to this narrowing gender gap, including women being less likely than men to quit and more likely to relapse if they do quit.⁹⁰