Psychodynamic theorists posit that substance abuse may arise from childhood dependency issues, wherein a child’s unmet caregiving needs lead to reliance on others for support and comfort. If these individuals encounter drugs or alcohol while seeking nurturing, their need for care can evolve into a dependence on substances. Psychodynamic theorists argue that personality traits associated with substance abuse stem from emotional deficiencies experienced in early development.
Research has found that people who misuse drugs and alcohol often show higher levels of dependence, antisocial behavior, novelty-seeking, and depression compared to non-users. However, a drawback of this viewpoint is the wide range of personality traits linked to substance abuse. Different studies suggest various traits as potential factors associated with substance abuse and dependency. As a result, current research does not conclusively determine whether any specific personality trait or group of traits can be directly attributed to disorders related to substance abuse.
Therapists following the psychodynamic theory help patients recognize and address underlying needs and conflicts that lead to substance abuse. They also work on guiding individuals in modifying their lifestyle related to substance use. However, this treatment approach is not very effective on its own and works better when combined with other techniques as part of a comprehensive treatment program.
Substance abuse and dependence are connected to different personality traits, according to various studies. These traits include dependence, impulsivity, and antisocial behavior. As a result, researchers have not identified one main trait or group of traits in substance-related disorders (Chassin et al., 2001; Rozin & Stoess, 1993).
Psychodynamic therapists aim to identify and address the underlying needs and conflicts that contribute to substance-related disorders, while also helping individuals modify their substance-related lifestyles. Nevertheless, research suggests that this approach is generally ineffective in treating these disorders.
Specialized treatment is necessary for individuals to achieve a drug-free state when faced with drug abuse or dependence. A comprehensive treatment program that combines psychodynamic therapy with other methods has proven to be more effective (Galanter & Brooks, 2001; Carroll & Rounsaville, 1995). According to the psychodynamic perspective, substance abusers have underlying dependency needs that stem from their early life experiences (Stetter, 2000; Shedler & Block, 1990).
According to experts, when parents fail to meet a young child’s need for care, the child may turn to others for help and comfort as a way of making up for the lack of nurturing during their early years. If this reliance on outside support includes experimenting with drugs, there is a chance of becoming addicted. In addition, psychodynamic theorists believe that some individuals respond to their early deficiencies by developing a personality that increases their vulnerability to substance abuse.
Various personality inventories and patient interviews have indicated that individuals who abuse or rely on drugs display a higher level of dependency, antisocial behavior, impulsivity, novelty-seeking, and depression when compared to others (Coffey et al., 2003; Cox et al., 2001; Finn et al., 2000). However, it is important to note that these findings only establish correlations without clarifying whether these personality traits predispose individuals to drug use or if drug use leads to the development of such traits. To investigate causation, a study analyzed the personality traits of a large group of nonalcoholic young men and observed their subsequent development (Jones, 1971, 1968).
A study conducted years later compared the characteristics of middle-aged men who developed issues with alcohol to those who did not. The study found that individuals with a tendency towards impulsivity are more likely to develop alcohol problems. This is supported by the fact that the men who had problems with alcohol exhibited greater impulsive behavior during their teenage years and continued this behavior as they reached middle age (Poulos et al. 1995). Additionally, a laboratory experiment observed that rats identified as “impulsive” consumed more alcohol when given the opportunity, unlike other rats (Poulos et al. 1995).
Researchers cannot currently determine any one specific personality trait or group of traits that are prevalent in substance-related disorders. The weakness of this argument is that there are many different personality traits associated with substance abuse and dependence, as various studies have found different “key” traits. Some individuals with drug addiction may be dependent, while others may be impulsive or antisocial (Chassin et al., 2001; Rozin & Stoess, 1993).
Behavioral and cognitive views suggest that operant conditioning may be influential in substance abuse. Behaviorists propose that the pleasurable effects of drugs, such as temporary tension reduction or mood elevation, serve as rewards and can increase the likelihood of seeking such experiences again (Rutledge & Sher, 2001). Furthermore, the rewarding nature of substances may prompt users to experiment with higher doses or alternative administration methods.
According to cognitive theorists, the use of rewards can create an expectation that drugs will be rewarding, which then motivates individuals to increase their drug use during times of tension (Chassin et al., 2001). Several studies have found evidence supporting this idea, showing that people tend to consume more alcohol or seek heroin when they feel stressed or anxious (Ham et al., 2002; Cooper, 1994).
According to a study by Marlatt et al. in 1975, participants were subjected to unfair criticism and belittlement by a planted confederate while working on a difficult anagram task. Afterwards, they were asked to participate in an “alcohol taste task” where they were supposed to compare and rate alcoholic beverages. It was observed that the harassed subjects consumed more alcohol during the taste task compared to the control subjects who had not been criticized. This suggests that behavioral and cognitive theorists argue that individuals use drugs as a form of self-medication when feeling tense. Consequently, it is expected that individuals experiencing anxiety, depression, or intense anger would have higher rates of drug abuse.
The prevalence of substance abuse and dependence is high among those with mood disorders (McDowell & Clodfelter, 2001; Swendsen & Merikangas, 2000). A study on 835 clinically depressed patients revealed that over a quarter of them engaged in drug abuse during depressive episodes (Hasin et al., 1985). Likewise, individuals with posttraumatic stress disorder, eating disorders, schizophrenia, antisocial personality disorder, histories of abuse, and other psychological issues demonstrate higher rates of drug abuse (Brown et al. 2003; Brooner et al., 1997; Yama et al., 1993).
Several behaviorists suggest that classical conditioning might also contribute to substance abuse and addiction (Drobes, Saladin, & Tiffany, 2001). Objects encountered while consuming drugs may function as conditioned stimuli and elicit similar pleasure as the drugs themselves. For instance, individuals who misuse heroin or amphetamines often derive comfort and alleviate withdrawal symptoms from mere exposure to a hypodermic needle or a familiar drug dealer.
In a parallel way, the presence of objects during withdrawal distress can cause withdrawal-like symptoms. For instance, a man who was previously addicted to heroin felt nauseous and experienced other withdrawal symptoms when he went back to the neighborhood where he had previously gone through withdrawal. This reaction ultimately led him to relapse and start using heroin again (O’Brien et al., 1975). Despite the possibility of classical conditioning playing a role in certain instances of drug abuse and dependence, it has not received extensive research backing as a pivotal factor in these patterns (Drobes et al., 2001).
A recent study has indicated that there might be biological factors contributing to drug misuse. Investigations on genetic predisposition and specific biochemical processes have offered some evidence in favor of these suspicions. Breeding experiments conducted over the years aimed at determining if certain animals possess a genetic inclination towards drug dependency (Li, 2000; Kurtz et al., 1996). Through multiple studies, scientists have successfully identified animals with a preference for alcohol over alternative drinks and subsequently mated them.
According to research, the offspring of certain animals have a notable affinity for alcohol (Melo et al., 1996). Similarly, studies involving human twins suggest that individuals may inherit a susceptibility to substance abuse (Tsuang et al., 2001; Kendler et al., 1994, 1992). A significant study found that among identical twins, there was a 54 percent concordance rate for alcohol abuse. This means that if one twin abused alcohol, the other twin did so in 54 percent of cases. In contrast, the concordance rate for fraternal twins was only 28 percent (Kaij, 1960).
Walters (2002) suggests that while the findings have specific conclusions, they do not completely exclude other interpretations. It is important to consider that parenting received by identical twins may be more similar compared to fraternal twins. Supporting evidence for the genetic influence on substance abuse and addiction can be found in studies examining rates of alcoholism among individuals who were adopted shortly after birth (Walters, 2002; Cadoret, 1995; Goldstein, 1994). These studies compare adoptees with biological parents who have alcohol dependency to adoptees with biological parents who do not show such dependence.
According to research, individuals with a family history of alcoholism have a higher likelihood of developing alcohol-related issues compared to those without such a background. This genetic predisposition is backed by findings in genetic linkage strategies and molecular biology techniques (Crabbe, 2002, 2001). In one study, it was found that a majority of individuals with alcohol dependence and half of those with cocaine dependence had an abnormal version of the dopamine-2 (D2) receptor gene. Conversely, less than 20 percent of individuals without dependence possessed this specific gene variant (Connor et al., 2002; Finckh, 2001; Blum & Noble, 1993).
In previous research, Cook & Gurling (2001) have established connections between various genes and substance-related disorders. Additionally, Wise (1996) has made advancements in comprehending the biochemical factors related to drug tolerance and withdrawal symptoms. Essentially, the consumption of a specific drug by an individual leads to heightened activity of particular neurotransmitters that typically function to provide comfort, alleviate pain, enhance mood, or boost attentiveness.
Repeated drug consumption leads to the brain decreasing its production of neurotransmitters, while the drug enhances their activity. As a result, the brain’s involvement becomes less important. Through continued drug use, the body gradually reduces its neurotransmitter production, necessitating higher doses for desired effects. Consequently, drug users develop tolerance as they rely on drugs rather than their own biological functions for comfort or alertness.
If an individual discontinues drug use suddenly, they will go through withdrawal symptoms as a result of a temporary decrease in their neurotransmitter supply. These symptoms will continue until the brain resumes its normal production of essential neurotransmitters. The specific neurotransmitters impacted vary depending on the specific drug employed. Misuse of alcohol or benzodiazepines can diminish GABA production in the brain, whereas opioid usage can reduce endorphin production. Moreover, prolonged consumption of cocaine or amphetamines might lower dopamine production in the brain (Volkow et al., 1999).
Scientists have discovered anandamides, neurotransmitters that work similarly to THC, the compound found in marijuana. The excessive use of marijuana can result in a reduction in the production of these neurotransmitters. This discovery explains why people who frequently use substances develop tolerance and encounter withdrawal symptoms (Johns, 2001; Biegon & Kerman, 1995). Nonetheless, there remains the question of what causes drugs to be enjoyable and what initially motivates specific individuals to use them.
Multiple brain-imaging studies indicate that various substances and stimuli, such as cocaine, amphetamines, caffeine, music, hugs, and words of praise, have the ability to activate a specific reward center in the brain. This reward center is commonly known as the “pleasure pathway” (Kelley & Berridge, 2002; Volkow & Fowler, 2000). The activation of dopamine, which is a crucial neurotransmitter within this pathway, is responsible for generating the pleasurable sensation connected with these stimulations.
It seems that certain drugs indirectly activate the reward center by causing biochemical reactions that increase dopamine activity. Alcohol, opioids, and marijuana are examples of substances that can initiate these reactions. Some experts suggest that individuals who misuse drugs may have a reward-deficiency syndrome, which means their reward center is not easily activated by normal life events (Blum et al., 2000; Nash, 1997). Consequently, they resort to using drugs as a way to stimulate this pleasure pathway, particularly during stressful periods.
The abnormal D2 receptor gene is considered a potential cause of this syndrome (Finckh, 2001; Lawford et al. , 1997). Psychodynamic therapists aim to assist patients with substance-related disorders in identifying and resolving the underlying needs and conflicts that contribute to the disorders. Furthermore, they endeavor to facilitate changes in the individuals’ patterns of substance-related behavior (Stetter, 2000; Hopper, 1995).
Although often applied, the effectiveness of this approach in treating substance-related disorders has been found to be limited (Cornish et al. 1995; Holder et al. , 1991). It is possible that regardless of the underlying causes, drug abuse or dependence becomes a persistent problem that requires direct treatment in order for individuals to achieve drug-free status. Combining psychodynamic therapy with other approaches in a comprehensive treatment program tends to yield better results (Galanter & Brooks, 2001; Carroll & Rounsaville, 1995). A widely used behavioral treatment for substance-related disorders is aversion therapy, which is based on the principles of classical conditioning.
Aversion therapy, a technique used to treat alcohol abuse and dependence, involves repeatedly pairing an unpleasant stimulus (such as an electric shock) with the consumption of the substance. This pairing is aimed at changing individuals’ reaction to the substance itself and reducing their desire for it. Specifically, in a particular version of this therapy, drinking behavior is associated with drug-induced nausea and vomiting (Owen-Howard, 2001; Welsh & Liberto, 2001).
Another method, called covert sensitization, involves instructing individuals with alcoholism to conjure up extremely distressing, repugnant, or terrifying situations while they are consuming alcohol (Cautela, 2000; Kassel et al., 1999). The purpose of associating these imaginary scenarios with liquor is to elicit negative reactions towards alcohol itself. Therapists may encourage clients to envision the following scenes: A behavioral strategy that has demonstrated efficacy in temporarily treating individuals who abuse cocaine and certain other substances is contingency management. This approach ties rewards (such as program privileges) to the provision of drug-free urine samples (Katz et al., 2001; Petry, 2000).
In one study, 68 percent of cocaine abusers who completed a six-month contingency training program achieved at least eight weeks of continuous abstinence (Higgins et al. , 1993). Behavioral interventions for substance abuse and dependence have usually had limited success as the sole form of treatment (Carroll & Rounsaville, 1995). A major problem is that these approaches can only be effective when individuals remain motivated to continue with them despite their unpleasantness or demands. Generally, behavioral treatments work best when combined with either biological or cognitive approaches (Kassel et al. 1999; Whorley, 1996).
Two popular approaches that combine cognitive and behavioral techniques aim to assist individuals in gaining control over their substance-related behaviors. One such approach is behavioral self-control training (BSCT), primarily used for addressing alcoholism. Therapists employing this method initially instruct clients to monitor their own drinking patterns (Miller et al., 1992; Miller, 1983). By documenting the times, locations, emotions, bodily changes, and other factors accompanying their drinking, individuals enhance their awareness of situations presenting a heightened likelihood of excessive alcohol consumption.
Individuals are educated on coping strategies to apply in situations where they experience difficulties. These strategies involve establishing boundaries for alcohol consumption, identifying when those boundaries are being approached, managing the pace of drinking (including spacing out drinks and sipping instead of consuming quickly), and utilizing relaxation techniques, assertiveness skills, and other coping behaviors instead of turning to alcohol. According to Walters (2000) and Hester (1995), about 70 percent of participants who complete this training exhibit some level of improvement, particularly among the young and those who are not physically dependent on alcohol.
The cognitive-behavioral approach known as relapse-prevention training is similar to BSCT (Spiegler & Guevremont, 2003; Parks & Marlatt, 2000, 1999) in assigning heavy drinkers similar tasks. It teaches them to plan ahead for drinking, including the appropriate number of drinks, type of drink, and circumstances in which to consume alcohol. This approach has been found to reduce the frequency of intoxication in some cases (Foxhall, 2001). Like BSCT, it is most effective for individuals who abuse alcohol but are not physically dependent on it (Meyer et al., 1989).
The approach has also been used, with some success, in the treatment of marijuana and cocaine abuse (Foxhall, 2001; Carroll & Rounsaville, 1995). Biological Treatments Biological approaches may be used to help people withdraw from substances, abstain from them, or simply maintain their level of use without further increases (Welsh & Liberto, 2001). As with the other forms of treatment, biological approaches alone rarely bring long-term improvement, but they can be helpful when combined with other approaches. Detoxification Detoxification is systematic and medically supervised withdrawal from a drug.
Some detoxification programs are offered on an outpatient basis. Others are located in hospitals and clinics and may also offer individual and group therapy, a “full-service” institutional approach that has become popular. One detoxification approach is to have clients withdraw gradually from the substance, taking smaller and smaller doses until they are off the drug completely.
Another approach to detoxification is to administer additional medications that can alleviate withdrawal symptoms (Malcolm et al. 2002; Schuckit, 1999). In certain cases, anti-anxiety medications are used to mitigate severe alcohol withdrawal symptoms such as delirium tremens and seizures. Detox programs have shown promise in helping motivated individuals overcome drug addiction (Zhao et al., 2001; Allan et al., 2000). However, individuals who do not receive further treatment—whether psychological, biological, or sociocultural—after successful detoxification, have a higher likelihood of relapse.
When individuals have successfully discontinued drug use, they must be cautious about reverting back to abusive or dependent behaviors.
As a support for resisting temptation, individuals with substance-related disorders may receive antagonist drugs that alter or prevent the effects of the addictive substance (Welsh & Liberto, 2001). Disulfiram (Antabuse), for instance, is frequently prescribed to individuals aiming to abstain from alcohol. When taken alone, a small dose of this medication appears to have minimal adverse effects. However, if alcohol is consumed while on disulfiram, the person will encounter severe nausea, vomiting, blushing, increased heart rate, dizziness, and potentially fainting.
Disulfiram can reduce the likelihood of alcohol consumption due to the anticipated severe reaction. This treatment has shown effectiveness with individuals who are committed to following the prescribed course. To address opioid dependence, narcotic antagonists may be employed. These medications bind to endorphin receptor sites in the brain, rendering the opioids ineffective and removing the pleasurable effects. Consequently, continued drug use becomes futile.
While narcotic antagonists have proved valuable in emergency situations for rescuing individuals from opioid overdoses, some clinicians view them as too hazardous for routine treatment of opioid dependence. The cautious administration of these antagonists is essential due to the likelihood of inducing severe withdrawal symptoms in individuals with addiction (Roozen et al., 2002; Ling et al., 2001). In recent times, partial antagonists, referred to as “partial agonists”, have been created as alternative narcotic antagonists that result in less severe withdrawal symptoms (Amass et al., 2000).
Recent research suggests that narcotic antagonists may have potential applications in addressing alcohol and cocaine dependence (Kiefer et al., 2003; O’Brien & McKay, 2002). Some studies, for instance, have reported the effectiveness of naltrexone, a narcotic antagonist, in reducing alcohol cravings (O’Malley et al., 2000, 1996, 1992). It is worth considering why narcotic antagonists, which primarily target the brain’s endorphin receptors, can contribute to the treatment of alcoholism that is largely attributed to activity in GABA sites. A plausible explanation lies in the brain’s reward center (Gianoulakis, 2001).
If different drugs ultimately activate the same pleasure pathway, it is logical to assume that antagonists for one drug could indirectly affect the impact of other drugs as well. Drug Maintenance Therapy addresses the issue of drug-related lifestyle being a bigger problem than the direct effects of the drug. Heroin addiction, for instance, causes significant harm through overdoses, use of unsterile needles, and involvement in criminal activities. Therefore, clinicians showed great enthusiasm when methadone maintenance programs were introduced in the 1960s as a treatment for heroin addiction (Dole & Nyswander, 1967, 1965).
In these programs, individuals with addiction are provided the opioid methadone as a substitute for heroin in a controlled medical setting. Despite developing a dependency on methadone, their addiction is effectively managed with medical supervision. Unlike heroin, methadone can be orally administered, eliminating the risks associated with needles and requiring just one daily dose. Initially, methadone programs demonstrated high effectiveness and led to the establishment of many such programs in the United States, Canada, and England (Payte, 1989).
During the 1980s, these programs lost popularity due to the dangers of methadone itself. Many clinicians and clients began to believe that substituting one addiction with another was not an acceptable solution for substance dependence (Cornish et al., 1995). In fact, withdrawing from methadone can be more challenging than stopping heroin use because the withdrawal symptoms can last almost twice as long (Blackmund et al., 2001; Kleber, 1981). Pregnant women who are maintained on methadone also have concerns about the drug’s impact on their fetus (DeCubas & Field, 1993).
Despite concerns, there has been renewed interest among clinicians in maintenance treatment with methadone or buprenorphine, a substitute drug. This is partly due to new research support and the rapid spread of the HIV virus among intravenous drug abusers and their partners and children. In the early 1990s, over a quarter of AIDS cases were directly linked to drug abuse, with intravenous drug abuse being the indirect cause in 60 percent of childhood AIDS cases.
Methadone treatment is not only safer than street opioid use, it also includes AIDS education and other health instructions in many programs (Sorensen & Copeland, 2000).
Research indicates that the effectiveness of methadone maintenance programs is enhanced by combining them with education, psychotherapy, family therapy, and employment counseling (O’Brien & McKay, 2002; Woody et al. , 1998). Currently, there are over 900 methadone clinics in the United States that provide the drug to as many as 160,000 patients at an average cost of $13 a day (ONDCP, 2002, 2000; Marks, 1998).
Sociocultural Therapies, as previously mentioned, focus on the belief that psychological issues arise within a social environment and are most effectively addressed within that context. Within the realm of substance-related disorders, three sociocultural approaches have been implemented: (1) self-help programs, (2) programs tailored to specific cultures and genders, and (3) community prevention programs. Self-help and residential treatment programs have been created by individuals who struggle with substance abuse to aid each other in recovery without the involvement of professional support.
The drug self-help movement originated in 1935 when two Ohio men met to explore alternative treatments for alcoholism. Their initial conversation led to the formation of Alcoholics Anonymous (AA), a self-help group. Members of AA engage in discussions about alcohol-related issues, exchange ideas, and offer support. AA has grown to include over 2 million members in 100,000 groups across the US and 150 other countries. It provides peer support, along with moral and spiritual principles, to aid individuals in overcoming alcohol addiction (AA World Services, 2003).
Different AA members find different elements of the organization beneficial. Some find peer support helpful (Galanter et al., 1990), while others find the spiritual aspect significant (Swora, 2001). Regular meetings are held, and members provide assistance to each other round the clock. In addition, AA offers guidance on living a sober life, emphasizing the importance of abstaining “one day at a time” and recognizing the truth that they have no control over alcohol and must cease drinking permanently if they wish to lead normal lives.
Al-Anon and Alateen are self-help organizations that provide support for individuals who have family members or loved ones with alcoholism. Additionally, there are self-help programs like Narcotics Anonymous and Cocaine Anonymous specifically designed for other substance-related disorders. Some self-help programs have evolved into residential treatment centers or therapeutic communities, such as Daytop Village and Phoenix House. These centers offer a drug-free environment where individuals who were once dependent on drugs can live, work, socialize, and undergo various therapies (including individual, group, and family therapies). Ultimately, the goal is to help these individuals transition back into community life (Landry, 1994).
The evidence supporting self-help and residential treatment programs mainly comes from individual testimonials. Many tens of thousands of people have shared that they are members of these programs and attribute them to positive changes in their lives (Gleick, 1995). While research on the programs has also yielded favorable results (Tonigan, 2001; Timko et al., 2000), the number of studies conducted has been limited (Watson et al., 1997). Additionally, there is a need for culture- and gender-sensitive programs as many people struggling with substance abuse come from impoverished and potentially violent environments.
Today, an increasing number of treatment programs aim to address the unique sociocultural pressures and challenges faced by drug abusers who are impoverished, homeless, or belong to minority groups (Straussner, 2001). Therapists with an understanding of their clients’ life difficulties are better equipped to tackle the stressors that frequently contribute to relapse. Similarly, therapists now recognize the need for distinct treatment approaches for women, in contrast to those designed for men (Knowlton, 1998; Lisansky-Gomberg, 1993). This is because women and men have varying physical and psychological responses to drugs (Hamilton, 1991).
The treatment of women who use drugs may be complex due to various factors, such as sexual abuse, potential pregnancy while using drugs, the challenges of being a parent, and the fear of legal consequences for drug abuse during pregnancy (Thompson & Kingree, 1998; Cornish et al., 1995). As a result, many women prefer seeking assistance at clinics or residential programs that are sensitive to their gender-specific needs. Moreover, certain programs even provide accommodation for children to live with their mothers during the recovery process (Clark, 2001).
One effective way to address substance-related disorders is through community prevention programs (Gottfredson & Wilson, 2003). Initially, drug-prevention initiatives were focused in schools, but now they are also available in workplaces, activity centers, and other community settings, as well as through the media (Bennett & Lehman, 2003; St. Pierre, 2001). These programs vary in their approaches with some advocating for complete abstinence from drugs and others promoting responsible use. Additionally, some programs aim to disrupt drug use while others aim to delay the age at which individuals first experiment with drugs.
Different programs may have different approaches to drug prevention, including offering drug education, teaching alternatives to drug use, attempting to alter the psychological state of potential users, aiming to change peer relationships, or combining these strategies. Prevention programs can target individuals (such as educating them about negative drug effects), families (through teaching parenting skills), peer groups (by promoting resistance to peer pressure), schools (by implementing strict drug policy enforcement), or the community as a whole (through public service announcements like the “Just say no” campaign in the past).
The most effective prevention efforts focus on multiple areas to consistently address drug abuse in individuals’ lives (Smith, 2001; Wagenaar et al., 2000). Certain prevention programs have even been designed for preschool children (Hall & Zigler, 1997). I believe that many individuals struggling with substance abuse have experienced a life-altering traumatic event, such as divorce, the death of a loved one, a difficult childhood, or a predisposed disposition.
This concept arouses a sense of engaging in unfamiliar activities. One example is divorce, which prompts individuals to reassess their decisions in life. Following a divorce, some individuals may succumb to alcoholism as they sense a lack of purpose in their lives. Similarly, the death of a loved one can elicit the same response. A difficult upbringing can result in an individual resorting to substance abuse as a means of erasing the traumatic experiences they have endured.
Predisposed disposition affects mainly babies whose parents were under the influence of substance abuse during pregnancy.