The apprehension is not necessarily data driven and is a cautionary response to the lack of clinical studies in pregnant women. The indication is a trade-off between the adverse effects of the drug, the risks associated with intercurrent diseases and pregnancy complications, and the efficiency of the drug to prevent or ameliorate such risks. In some cases, the use of drugs in pregnancy carries benefits that outweigh the risks. For example, high fever is harmful for the fetus in the early months, thus the use of paracetamol (acetaminophen) is generally associated with lower risk than the fever itself. Similarly, diabetes mellitus during pregnancy may need intensive therapy with insulin to prevent complications to mother and baby. Pain management for the mother is another important area where an evaluation of the benefits and risks is needed. NSAIDs such as Ibuprofen and Naproxen are probably safe for use for a short period of time, 48–72 hours, once the mother has reached the second trimester. If taking aspirin for pain management the mother should never take a dose higher than 100 mg.

A woman may elect to discontinue alcohol once she knows that she is pregnant. A woman can have serious symptoms that accompany alcohol withdrawal during pregnancy. These symptoms can be treated during pregnancy with benzodiazepine.

Cannabis consumption in pregnancy might be associated with restrictions in growth of the fetus, miscarriage, and cognitive deficits. The American Congress of Obstetricians and Gynecologists recommended that cannabis use be stopped before and during pregnancy, Cannabis is the most commonly used illicit substance

among pregnant women.

Although it is difficult to draw firm conclusions, there is some evidence that prenatal exposure to marijuana may be associated with deficits in language, attention, cognitive performance, and delinquent behaviors. THC exposure in rats during the prenatal developmental phase may cause epigenetic changes in gene expression, but there is limited knowledge about the risk for psychiatric disorders because of ethical barriers to studying the developing human brain. While animal studies cannot take into account factors that could influence the effects of cannabis on human maternal exposure, such as environmental and social factors, a 2011 review of rodent studies by Campolongo "et al." said there was "... increasing evidence from animal studies showing that cannabinoid drugs ... induce enduring neurobehavioral abnormalities in the exposed offspring ..." Campolongo "et al." added that "clinical studies report hyperactivity, cognitive impairments and altered emotionality in humans exposed in utero to cannabis". Martin "et al." investigated recent trends in substance abuse treatment admissions for cannabis use in pregnancy in the US, based on Treatment Episodes Data Set (TEDS) from 1992 to 2012, and discovered that, while the proportion of treatment admissions for pregnant women was stable (about 4%), the admissions for women who were pregnant and reported any marijuana use grew from 29% to 43%. A 2015 review found that cannabis use by pregnant mothers impaired brain maturation in their children, and that it also predisposed their children to neurodevelopmental disorders.

U.S. Code of Federal Regulations requires that certain drugs and biological products must be labelled very specifically with respect to their effects on pregnant populations, including a definition of a "pregnancy category." These rules are enforced by the Food and Drug Administration (FDA). The FDA does not regulate labelling for all hazardous and non-hazardous substances and some potentially hazardous substances are not assigned a pregnancy category.

Australia’s categorisations system takes into account the birth defects, the effects around the birth or when the mother gives birth, and problems that will arise later in the child's life caused from the drug taken. The system places them into a category of their severity that the drug could cause to the infant when it crosses the placenta(Australian Government, 2014).

When an infant is born and appears to be healthy, the baby may still have non-visible disorders and organ defects due to exposure to alcohol during the pregnancy. Social problems in the child have been found to be associated with alcohol use during gestation. Alcohol is a cause of microcephaly.

Alcohol use during pregnancy does not effect the ability to breastfeed the infant. In addition, an infant may breastfeed even if the mother continues to consume alcohol after the birth. An infant born to a mother that has an alcohol dependency may go through alcohol withdrawal after the birth.

Research that looks at barriers to cannabis treatment frequently cites a lack of interest in treatment, lack of motivation and knowledge of treatment facilities, an overall lack of facilities, costs associated with treatment, difficulty meeting program eligibility criteria and transport difficulties. A technical report compiled by Australia's National Cannabis Centre.

The role of the endocannabinoid system (ECS) in female fertility has long been suspected and studied. Most studies through 2013 linking development of the fetus and cannabis show effects of consumption during the gestational period, but abnormalities in the endocannabinoid system during the phase of placental development are also linked with problems in pregnancy. According to Sun and Dey (2012), endocannabinoid signaling plays a role in "female reproductive events, including preimplantation embryo development, oviductal embryo transport, embryo implantation, placentation, and parturition". Karusu "et al" (2011) said that a "clear correlation ... in the actual reproductive tissues of miscarrying versus healthy women has yet to be established. However, the adverse effects of marijuana smoke and THC on reproductive functions point to processes that are modulated by ECS."

Keimpema and colleagues (2011) said, "Prenatal cannabis exposure can lead to growth defects during formation of the nervous system"; "[c]annabis impacts the formation and functions of neuronal circuitries by targeting cannabinoid receptors ... By indiscriminately prolonging the "switched-on" period of cannabinoid receptors, cannabis can hijack endocannabinoid signals to evoke molecular rearrangements, leading to the erroneous wiring of neuronal networks". A report prepared for the Australian National Council on Drugs concluded cannabis and other cannabinoids are contraindicated in pregnancy as they may interact with the endocannabinoid system.

Columbia University, in collaboration with the National Institute on Drug Abuse (NIDA), is undertaking a clinical trial that looks at the effects of combined medication on cannabis dependency, to see if lofexidine in combination with dronabinol is superior to placebo in achieving abstinence, reducing cannabis use and reducing withdrawal in cannabis-dependent patients seeking treatment for their marijuana use. Men and women between the ages of 18–60 who met DSM-IV criteria for current marijuana dependence were enrolled in a 12-week trial that started in January 2010.

Georgotas & Zeidenberg (1979) conducted an experiment where they gave an average daily dose of 210 mg of tetrahydrocannabinol (THC), the ingredient in cannabis which is responsible for its psychological effects, to a group of volunteers over a 4-week period. After test ended, the subjects were found to be "irritable, uncooperative, resistant and at times hostile," and many of the patients experienced insomnia. These effects were likely due to withdrawal from the drug and lasted about 3 weeks after the experiment.

A 2014 Cochrane Collaboration review found insufficient data to evaluate the effectiveness of gabapentin and acetylcysteine in the treatment of cannabis dependence and that it warrants further investigation.

A number of medications have been approved for the treatment of substance abuse. These include replacement therapies such as buprenorphine and methadone as well as antagonist medications like disulfiram and naltrexone in either short acting, or the newer long acting form. Several other medications, often ones originally used in other contexts, have also been shown to be effective including bupropion and modafinil. Methadone and buprenorphine are sometimes used to treat opiate addiction. These drugs are used as substitutes for other opioids and still cause withdrawal symptoms.

Antipsychotic medications have not been found to be useful. Acamprostate is a glutamatergic NMDA antagonist, which helps with alcohol withdrawal symptoms because alcohol withdrawal is associated with a hyperglutamatergic system.

Psychedelics, such as LSD and psilocin, may have anti-addictive properties.

From the applied behavior analysis literature, behavioral psychology, and from randomized clinical trials, several evidenced based interventions have emerged: behavioral marital therapy, motivational Interviewing, community reinforcement approach, exposure therapy, contingency management They help suppress cravings and mental anxiety, improve focus on treatment and new learning behavioral skills, ease withdrawal symptoms and reduce the chances of relapse.

In children and adolescents, cognitive behavioral therapy (CBT) and family therapy currently has the most research evidence for the treatment of substance abuse problems. Well-established studies also include ecological family-based treatment and group CBT. These treatments can be administered in a variety of different formats, each of which has varying levels of research support Research has shown that what makes group CBT most effective is that it promotes the development of social skills, developmentally appropriate emotional regulatory skills and other interpersonal skills. A few integrated treatment models, which combines parts from various types of treatment, have also been seen as both well-established or probably effective. A study on maternal alcohol and drug use has shown that integrated treatment programs have produced significant results, resulting in higher negative results on toxicology screens. Additionally, brief school-based interventions have been found to be effective in reducing adolescent alcohol and cannabis use and abuse. Motivational interviewing can also be effective in treating substance use disorder in adolescents.

Alcoholics Anonymous and Narcotics Anonymous are one of the most widely known self-help organizations in which members support each other not to use alcohol. Social skills are significantly impaired in people suffering from alcoholism due to the neurotoxic effects of alcohol on the brain, especially the prefrontal cortex area of the brain. It has been suggested that social skills training adjunctive to inpatient treatment of alcohol dependence is probably efficacious, including managing the social environment.

It is recommended for women planning pregnancy to stop smoking. It is important to examine these effects because smoking before, during and after pregnancy is not an unusual behavior among the general population and can have detrimental health impacts, especially among both mother and child as a result. In 2011, approximately 10% of pregnant women in data collected from 24 states reported smoking during the last three months of their pregnancy.

If one does continue to smoke after giving birth, however, it is still more beneficial to breastfeed than to completely avoid this practice altogether. There is evidence that breastfeeding offers protection against many infectious diseases, especially diarrhea. Even in babies exposed to the harmful effects of nicotine through breast milk, the likelihood of acute respiratory illness is significantly diminished when compared to infants whose mothers smoked but were formula fed. Regardless, the benefits of breastfeeding outweigh the risks of nicotine exposure.

The pregnancy category of a medication is an assessment of the risk of fetal injury due to the pharmaceutical, if it is used as directed by the mother during pregnancy. It does "not" include any risks conferred by pharmaceutical agents or their metabolites in breast milk.

Every drug has specific information listed in its product literature. The British National Formulary used to provide a table of drugs to be avoided or used with caution in pregnancy, and did so using a limited number of key phrases, but now Appendix 4 (which was the Pregnancy table) has been removed. Appendix 4 is now titled "Intravenous Additives". However, information that was previously available in the former Appendix 4 (pregnancy) and Appendix 5 (breast feeding) is now available in the individual drug monographs.

The use of recreational drugs in pregnancy can cause various pregnancy complications.

- Ethanol during pregnancy can cause fetal alcohol syndrome and fetal alcohol spectrum disorder. Studies have shown that light to moderate drinking during pregnancy might not pose a risk to the fetus, although no amount of alcohol during pregnancy can be guaranteed to be absolutely safe.

- Tobacco smoking during pregnancy can cause a wide range of behavioral, neurological, and physical difficulties. Smoking during pregnancy causes twice the risk of premature rupture of membranes, placental abruption and placenta previa. Smoking is associated with 30% higher odds of preterm birth.

- Prenatal cocaine exposure is associated with premature birth, birth defects and attention deficit disorder.

- Prenatal methamphetamine exposure can cause premature birth and congenital abnormalities. Short-term neonatal outcomes show small deficits in infant neurobehavioral function and growth restriction. Long-term effects in terms of impaired brain development may also be caused by methamphetamine use.

- Cannabis in pregnancy has been shown to be teratogenic in large doses in animals, but has not shown any teratogenic effects in humans.

These drugs block dopamine receptors and some also block serotonin receptors (such as chlorpromazine, the first antipsychotic used clinically). Having been on one or more antipsychotics for any appreciable amount of time results in dramatically reduced sensitivity to others with similar mechanisms of action. However, an antipsychotic with a substantial disparity in pharmacology (e.g. haloperidol and quetiapine) may retain significant efficacy.

MAO inhibitor drugs block an enzyme system resulting in increased stores of monoamine neurotransmitters. More common antidepressants such as tricyclic antidepressants and SSRIs block reuptake transporters causing increased levels of norepinephrine or serotonin in synapses. Mood stabilizers include lithium and many anticonvulsants, such as carbamazepine and lamotrigine are also used for mood disorders. This would demonstrate little to zero cross-tolerance with serotonergic or lithium treatment.

Intrauterine exposure to environmental toxins in pregnancy has the potential to cause adverse effects on the development of the embryo/fetus and to cause pregnancy complications. Air pollution has been associated with low birth weight infants. Conditions of particular severity in pregnancy include mercury poisoning and lead poisoning. To minimize exposure to environmental toxins, the "American College of Nurse-Midwives" recommends: checking whether the home has lead paint, washing all fresh fruits and vegetables thoroughly and buying organic produce, and avoiding cleaning products labeled "toxic" or any product with a warning on the label.

Pregnant women can also be exposed to toxins in the workplace, including airborne particles. The effects of wearing N95 filtering facepiece respirators are similar for pregnant women as non-pregnant women, and wearing a respirator for one hour does not affect the fetal heart rate.

Immunizations have not been found to cause miscarriage. There is no significant association between antidepressant medication exposure and spontaneous abortion. The risk of miscarriage is not likely decrease by discontinuing SSRI prior to pregnancy. Some available data suggest that there is a small increased risk of miscarriage for women taking any antidepressant, though this risk becomes less statistically significant when excluding studies of poor quality.

Medicines that increase the risk of miscarriage include:

- retinoids

- nonsteroidal anti-inflammatory drugs (NSAIDs) , such as ibuprofen

- misoprostol

- methotrexate

Ionizing radiation levels given to a woman during cancer treatment cause miscarriage. Exposure can also impact fertility. The use of chemotherapeutic drugs used to treat childhood cancer increases the risk of miscarriage.

Treatment for Antenatal depression poses many challenges because the baby is also affected by any treatments given to the mother. It is suggested that the emotional aspects are handled first which includes;

- Taking it easy by relaxing when possible.

- Spending time with your partner.

- Talk about your fears & anxieties involving the pregnancy.

- Manage your stress.

Counseling is highly recommended to any woman suffering from antenatal depression. It is a very effective way for the mother to express her feelings and explain in her own words what she is feeling. This is very effective in that it gives the doctors a better insight into the symptoms and their severity. In severe cases Medication can be prescribed. This is usually only done if the symptoms have proven so severe that they interfere with day-to-day life, self care, and ability to sleep. During pregnancy, there are two main kinds of antidepressants used during pregnancy; Tricyclic antidepressants (TCAs)and Selective serotonin reuptake inhibitors (SSRIs).Once prescribed, anti-depressant medication has been found to be extremely effective in treating antenatal depression. Patients can expect to feel an improvement in mood in roughly 2 to 3 weeks on average, and can begin to feel themselves truly connect with their baby. Reported benefits of medication include returned appetite, feeling of connect, increased mood, increased energy, and better concentration. Side effects are minor, though they are reported in some cases. Currently, no abnormalities of the baby have been associated with the use of antidepressants during pregnancy.

It may be true that maternal SSRI use during pregnancy can lead to difficulty for their newborn adjusting to conditions outside of the womb immediately following birth. Some studies indicate that infants with exposure to SSRIs in the second and third trimester were more likely to be admitted to intensive care following their birth for respiratory, cardiac, low weight and other reasons, and that infants with prenatal SSRI exposure exhibited less motor control upon delivery than infants who were not exposed to SSRIs. Newborns who were exposed to SSRIs for five months or more prior to birth were at a greater risk for lower Apgar scores 1 and 5 minutes after delivery, indicating they were of lesser health than newborns who were not exposed to SSRIs before birth. However, prenatal SSRI exposure was not found to have a significant impact the long-term mental and physical health of the children. These results are not independent of any effects of prenatal depression on infants.

The past exposure theory suggests that exposure to psychiatric medication alters neural synapses, introducing an that was not previously present. Discontinuation of the drug is expected to result in symptoms of psychiatric illness which resolve once the drug is restarted. This theory suggests that while it may appear that the medication is working, it is only treating a disorder caused by the medication itself. New exposure to psychiatric medication may lead to heightened sensitivity to the effects of drugs and alcohol, which has a deteriorating effect on the patient.

The self-medication theory suggests that people with severe mental illnesses misuse substances in order to relieve a specific set of symptoms and counter the negative side-effects of antipsychotic medication.

Khantizan proposes that substances are not randomly chosen, but are specifically selected for their effects. For example, using stimulants such as nicotine or amphetamines can be used to combat the sedation that can be caused by higher doses of certain types of (usually typical) antipsychotic medication. Conversely, some people taking medications with a stimulant effect such as the SNRI antidepressants Effexor (venlafaxine) or Wellbutrin (bupropion) may seek out benzodiazepines or opioid narcotics to counter the anxiety and insomnia that such medications sometimes evoke.

Some studies show that nicotine administration can be effective for reducing motor side-effects of antipsychotics, with both bradykinesia (stiff muscles) and dyskinesia(involuntary movement) being prevented.

Antenatal depression, also known as Prenatal depression, is a form of clinical depression that can affect a woman during pregnancy, and can be a precursor to postpartum depression if not properly treated. It is estimated that 7% to 20% percent of pregnant women are affected by this condition. Any form of prenatal stress felt by the mother can have negative effects on various aspects of fetal development, which can cause harm to the mother and child. Antenatal depression is often caused by the stress and worry that pregnancy can bring, only at a more severe level. Other risk factors include unplanned pregnancy, difficulty becoming pregnant, history of abuse, and economic or family situations.

Commonly, symptoms involve how the patient views herself, how she feels about going through such a life changing event, the restrictions on the mother's lifestyle that motherhood will place, or how the partner or family feel about the baby. Pregnancy places significant strain on a woman's body, so some stress, mood swings, sadness, irritability, pain, and memory changes are to be expected. Antenatal depression can be extremely dangerous for the health of the mother, and the baby, if not properly treated.

A withdrawal syndrome, also called a discontinuation syndrome is a set of symptoms occurring in discontinuation or dosage reduction of some types of medications. The risk of a discontinuation syndrome occurring increases with dosage and length of use.

- Alcohol withdrawal syndrome, symptoms seen when an individual reduces or stops alcohol consumption after periods of excessive alcohol intake

- Antidepressant discontinuation syndrome, a syndrome that can occur following the interruption, dose reduction, or discontinuation of SSRI or SNRI medications

- Antipsychotic withdrawal syndrome or dopamine supersensitivity psychosis, symptoms seen when an individual reduces or suddenly stops antipsychotics

- Benzodiazepine withdrawal syndrome, symptoms that appear when a long term user stops taking benzodiazepines or reduces the dosage

- Cannabis withdrawal, a form of withdrawal associated with the substance cannabis

- Drug withdrawal

- Neonatal withdrawal, a withdrawal syndrome of infants, caused by administration of drugs or the prenatal exposure to a substance

- Nicotine withdrawal, the effects felt by a person who is nicotine dependent and suddenly stops or significantly reduces his or her nicotine intake

- Opioid withdrawal, symptoms seen cessation or rapid reduction of intake of opioid class drugs

The data presented is for comparative and illustrative purposes only, and may have been superseded by updated data.