Heroin-assisted treatment (HAT, the medical prescription of heroin) has been available in Switzerland since 1994. A 2001 study found a high rate of treatment retention and significant improvement in health, social situation and likelihood to leave the illegal drug scene in enrolled participants. The study found that the most common reason for discharge was the start of abstinence treatment or methadone treatment. The study also found that heroin-assisted treatment is cost-beneficial on a society level due to reduced criminality and improved overall health of participants.

The heroin-assisted treatment program was introduced in Switzerland to combat the increase in heroin use in the 1980s and 1990s and written into law 2010 as one pillar of a four-pillar strategy using repression, prevention, treatment and risk reduction. Usually, only a small percentage of patients receives heroin and have to fulfil a number of criteria. Since then, HAT programs have been adopted in the Netherlands, United Kingdom, Germany, Spain, Denmark, Belgium, Canada, and Luxembourg.

There are efforts to decrease the number of opioids prescribed in an effort to decrease opioid use disorder and deaths related to opioid use.

Little attention has focused on the degree that benzodiazepines are abused as a primary drug of choice, but they are frequently abused alongside other drugs of abuse, especially alcohol, stimulants and opiates. The benzodiazepine most commonly abused can vary from country to country and depends on factors including local popularity as well as which benzodiazepines are available. Nitrazepam for example is commonly abused in Nepal and the United Kingdom, whereas in the United States of America where nitrazepam is not available on prescription other benzodiazepines are more commonly abused. In the United Kingdom and Australia there have been epidemics of temazepam abuse. Particular problems with abuse of temazepam are often related to gel capsules being melted and injected and drug-related deaths. Injecting most benzodiazepines is dangerous because of their relative insolubility in water (with the exception of midazolam), leading to potentially serious adverse health consequences for users.

Benzodiazepines are a commonly misused class of drug. A study in Sweden found that benzodiazepines are the most common drug class of forged prescriptions in Sweden. Concentrations of benzodiazepines detected in impaired motor vehicle drivers often exceeding therapeutic doses have been reported in Sweden and in Northern Ireland. One of the hallmarks of problematic benzodiazepine drug misuse is escalation of dose. Most licit prescribed users of benzodiazepines do not escalate their dose of benzodiazepines.

Addiction is a complex but treatable condition. It is characterized by compulsive drug craving, seeking, and use that persists even if the user is aware of severe adverse consequences. For some people, addiction becomes chronic, with periodic relapses even after long periods of abstinence. As a chronic, relapsing disease, addiction may require continued treatments to increase the intervals between relapses and diminish their intensity. While some with substance issues recover and lead fulfilling lives, others require ongoing additional support. The ultimate goal of addiction treatment is to enable an individual to manage their substance misuse; for some this may mean abstinence. Immediate goals are often to reduce substance abuse, improve the patient's ability to function, and minimize the medical and social complications of substance abuse and their addiction; this is called "harm reduction".

Treatments for addiction vary widely according to the types of drugs involved, amount of drugs used, duration of the drug addiction, medical complications and the social needs of the individual. Determining the best type of recovery program for an addicted person depends on a number of factors, including: personality, drugs of choice, concept of spirituality or religion, mental or physical illness, and local availability and affordability of programs.

Many different ideas circulate regarding what is considered a successful outcome in the recovery from addiction. Programs that emphasize controlled drinking exist for alcohol addiction. Opiate replacement therapy has been a medical standard of treatment for opioid addiction for many years.

Treatments and attitudes toward addiction vary widely among different countries. In the US and developing countries, the goal of commissioners of treatment for drug dependence is generally total abstinence from all drugs. Other countries, particularly in Europe, argue the aims of treatment for drug dependence are more complex, with treatment aims including reduction in use to the point that drug use no longer interferes with normal activities such as work and family commitments; shifting the addict away from more dangerous routes of drug administration such as injecting to safer routes such as oral administration; reduction in crime committed by drug addicts; and treatment of other comorbid conditions such as AIDS, hepatitis and mental health disorders. These kinds of outcomes can be achieved without eliminating drug use completely. Drug treatment programs in Europe often report more favorable outcomes than those in the US because the criteria for measuring success are functional rather than abstinence-based. The supporters of programs with total abstinence from drugs as a goal believe that enabling further drug use means prolonged drug use and risks an increase in addiction and complications from addiction.

Early treatment of acute withdrawal often includes medical detoxification, which can include doses of anxiolytics or narcotics to reduce symptoms of withdrawal. An experimental drug, ibogaine, is also proposed to treat withdrawal and craving.

Neurofeedback therapy has shown statistically significant improvements in numerous researches conducted on alcoholic as well as mixed substance abuse population. In chronic opiate addiction, a surrogate drug such as methadone is sometimes offered as a form of opiate replacement therapy. But treatment approaches universal focus on the individual's ultimate choice to pursue an alternate course of action.

Therapists often classify patients with chemical dependencies as either interested or not interested in changing.

Treatments usually involve planning for specific ways to avoid the addictive stimulus, and therapeutic interventions intended to help a client learn healthier ways to find satisfaction. Clinical leaders in recent years have attempted to tailor intervention approaches to specific influences that affect addictive behavior, using therapeutic interviews in an effort to discover factors that led a person to embrace unhealthy, addictive sources of pleasure or relief from pain.

From the applied behavior analysis literature and the behavioral psychology literature, several evidenced-based intervention programs have emerged (1) behavioral marital therapy (2) community reinforcement approach (3) cue exposure therapy and (4) contingency management strategies. In addition, the same author suggests that social skills training adjunctive to inpatient treatment of alcohol dependence is probably efficacious.

Individuals with a substance abuse history are at an increased risk of misusing benzodiazepines.

Several (primary research) studies, even into the last decade, claimed, that individuals with a history of familial abuse of alcohol or who are siblings or children of alcoholics appeared to respond differently to benzodiazepines than so called "genetically healthy" persons, with males experiencing increased euphoric effects and females having exaggerated responses to the adverse effects of benzodiazepines.

Whilst all benzodiazepines have abuse potential, certain characteristics increase the potential of particular benzodiazepines for abuse. These characteristics are chiefly practical ones—most especially, availability (often based on popular perception of 'dangerous' versus 'non-dangerous' drugs) through prescribing physicians or illicit distributors. Pharmacological and pharmacokinetic factors are also crucial in determining abuse potentials. A short elimination half-life, high potency and a rapid onset of action are characteristics which increase the abuse potential of benzodiazepines. The following table provides the elimination half-life, relevant potency to other benzodiazepines, speed of onset of action and duration of behavioural effects.

Residential drug treatment can be broadly divided into two camps: 12-step programs and therapeutic communities. Twelve-step programs are a nonclinical support-group and faith-based approach to treating addiction. Therapy typically involves the use of cognitive-behavioral therapy, an approach that looks at the relationship between thoughts, feelings and behaviors, addressing the root cause of maladaptive behavior. Cognitive-behavioral therapy treats addiction as a behavior rather than a disease, and so is subsequently curable, or rather, unlearnable. Cognitive-behavioral therapy programs recognize that, for some individuals, controlled use is a more realistic possibility.

One of many recovery methods are 12-step recovery programs, with prominent examples including Alcoholics Anonymous, Narcotics Anonymous, Drug Addicts Anonymous and Pills Anonymous. They are commonly known and used for a variety of addictions for the individual addicted and the family of the individual. Substance-abuse rehabilitation (rehab) centers offer a residential treatment program for some of the more seriously addicted, in order to isolate the patient from drugs and interactions with other users and dealers. Outpatient clinics usually offer a combination of individual counseling and group counseling. Frequently, a physician or psychiatrist will prescribe medications in order to help patients cope with the side effects of their addiction. Medications can help immensely with anxiety and insomnia, can treat underlying mental disorders (cf. self-medication hypothesis, Khantzian 1997) such as depression, and can help reduce or eliminate withdrawal symptomology when withdrawing from physiologically addictive drugs. Some examples are using benzodiazepines for alcohol detoxification, which prevents delirium tremens and complications; using a slow taper of benzodiazepines or a taper of phenobarbital, sometimes including another antiepileptic agent such as gabapentin, pregabalin, or valproate, for withdrawal from barbiturates or benzodiazepines; using drugs such as baclofen to reduce cravings and propensity for relapse amongst addicts to any drug, especially effective in stimulant users, and alcoholics (in which it is nearly as effective as benzodiazepines in preventing complications); using clonidine, an alpha-agonist, and loperamide for opioid detoxification, for first-time users or those who wish to attempt an abstinence-based recovery (90% of opioid users relapse to active addiction within eight months or are multiple relapse patients); or replacing an opioid that is interfering with or destructive to a user's life, such as illicitly-obtained heroin, dilaudid, or oxycodone, with an opioid that can be administered legally, reduces or eliminates drug cravings, and does not produce a high, such as methadone or buprenorphine – opioid replacement therapy – which is the gold standard for treatment of opioid dependence in developed countries, reducing the risk and cost to both user and society more effectively than any other treatment modality (for opioid dependence), and shows the best short-term and long-term gains for the user, with the greatest longevity, least risk of fatality, greatest quality of life, and lowest risk of relapse and legal issues including arrest and incarceration.

In a survey of treatment providers from three separate institutions, the National Association of Alcoholism and Drug Abuse Counselors, Rational Recovery Systems and the Society of Psychologists in Addictive Behaviors, measuring the treatment provider's responses on the "Spiritual Belief Scale" (a scale measuring belief in the four spiritual characteristics of AA identified by Ernest Kurtz); the scores were found to explain 41% of the variance in the treatment provider's responses on the "Addiction Belief Scale" (a scale measuring adherence to the disease model or the free-will model of addiction).

The use of stimulants in humans causes rapid weight loss, cardiovascular effects such as an increase in heart rate, respirations and blood pressure, emotional or mental side effects such as paranoia, anxiety, and aggression, as well as a change in the survival pathway known as the reward/reinforcement pathway in our brain. An increase in energy, a reduced appetite, increased alertness and a boost in confidence are all additional side effects of stimulant use when introduced to the body.

The symptoms of stimulant use disorder include failure to control usage and frequency of use, an intense craving for the drug, increased use over time to obtain the same effects, known as a developed tolerance, and a continued use despite negative repercussions and interference in one’s everyday life and functioning. Furthermore, a disorder is noted when withdrawal symptoms occur because of a decrease in the drug amount and frequency, as well as stopping the use of the drug entirely. These withdrawal symptoms can last for days, weeks, months, and on rare occasions, years, depending on the frequency and dosages used by the individual. These symptoms include, but are not limited to, increased appetite, decreased energy, depression, loss of motivation and interest in once pleasurable activities, anxiety, insomnia, agitation and an intense craving for the drug. Unless intensive medical and psychological treatment is sought after, there is a very high likelihood of relapse among the user.

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.

Death can be prevented in individuals who have overdosed on opioids if they receive basic life support and naloxone is administered soon after the overdose occurs. Naloxone is effective at reversing the cause, rather than just the symptoms, of an opioid overdose. A longer-acting variant of naloxone is naltrexone. Naltrexone is primarily used to treat opioid and alcohol dependence.

Programs to provide drug users and their caregivers with naloxone are recommended. In the United States its use is estimated to have prevented 10,000 opioid overdose deaths. Healthcare institution-based naloxone prescription programs have also helped reduce rates of opioid overdose in the US state of North Carolina, and have been replicated in the US military. Nevertheless, scale-up of healthcare-based opioid overdose interventions are limited by providers’ insufficient knowledge and negative attitudes towards prescribing take-home naloxone to prevent opioid overdose. Programs training police and fire personnel in opioid overdose response using naloxone have also shown promise.

Although opioid overdose accounts for the leading cause of accidental death, it can be prevented in primary care settings. Clear protocols for staff at emergency departments and urgent care centers can reduce opioid prescriptions for individuals presenting in these settings who engage in drug seeking behaviors or who have a history of substance abuse. Providers should routinely screen patients using tools such as the CAGE-AID and the Drug Abuse Screening Test (DAST-10) to screen adults and the CRAFFT to screen adolescents aged 14–18 years. Other “drug seeking” behaviors and physical indications of drug use should be used as clues to perform formal screenings.

Individuals diagnosed with opioid dependence should be prescribed naloxone to prevent overdose and/or should be directed to one of the many intervention/treatment options available, such as needle exchange programs and treatment centers. Brief motivational interviewing can also be performed by the clinician during patient visits and has been shown to improve patient motivation to change their behavior. Despite these opportunities, the dissemination of prevention interventions in the US has been hampered by the lack of coordination and sluggish federal government response.

Prescription monitoring program allow physicians to view individuals' history of prescribed opioids and other controlled substances to prevent risky behaviors, such as doctor shopping and drug diversion. These programs are operational in 49 states and the District of Columbia, and have generally been found to decrease prescribing of opioids.

Regulative policies, such as Florida’s pill mill law, have also been found to decrease opioid prescribing and use, which are both correlated with opioid overdoses. Florida's pill mill law addressed pill mills, or rogue pain management clinics where prescription drugs are inappropriately prescribed and dispensed, and required these clinics to register with the state, have a physician-owner, created inspection requirements, and established prescribing and dispensing requirements and prohibitions for physicians at these clinics.

Amphetamine dependence refers to a state of psychological dependence on a drug in the amphetamine class. In individuals with substance use disorder (problematic use or abuse with dependence), psychotherapy is currently the best treatment option as no pharmacological treatment has been approved. Tolerance is expected to develop with regular substituted amphetamine use. When substituted amphetamines are abused, drug tolerance develops rapidly.

Severe withdrawal associated with dependence from recreational substituted amphetamine use can be difficult for a user to cope with. Long-term use of certain substituted amphetamines, particularly methamphetamine, can reduce dopamine activity in the brain. Psychostimulants that increase dopamine and mimic the effects of substituted amphetamines, but with lower abuse liability, could theoretically be used as replacement therapy in amphetamine dependence. However, the few studies that used amphetamine, bupropion, methylphenidate and modafinil as a replacement therapy did not result in less methamphetamine use or craving.

In 2013, overdose on amphetamine, methamphetamine, and other compounds implicated in an "amphetamine use disorder" resulted in an estimated 3,788 deaths worldwide (3,425–4,145 deaths, 95% confidence).

Barbiturate dependence develops with regular use of barbiturates. This in turn may lead to a need for increasing doses of the drug to get the original desired pharmacological or therapeutic effect. Barbiturate use can lead to both addiction and physical dependence, and as such they have a high potential for abuse. Management of barbiturate dependence involves considering the affected person's age, comorbidity and the pharmacological pathways of barbiturates. Psychological addiction to barbiturates can develop quickly. The GABA receptor, one of barbiturates' main sites of action, is thought to play a pivotal role in the development of tolerance to and dependence on barbiturates, as well as the euphoric "high" that results from their abuse. The mechanism by which barbiturate tolerance develops is believed to be different from that of ethanol or benzodiazepines, even though these drugs have been shown to exhibit cross-tolerance with each other. The management of a physical dependence on barbiturates is stabilisation on the long-acting barbiturate phenobarbital followed by a gradual titration down of dose. The slowly eliminated phenobarbital lessens the severity of the withdrawal syndrome and reduces the chances of serious barbiturate withdrawal effects such as seizures. Antipsychotics are not recommended for barbiturate withdrawal (or other CNS depressant withdrawal states) especially clozapine, olanzapine or low potency phenothiazines e.g. chlorpromazine as they lower the seizure threshold and can worsen withdrawal effects; if used extreme caution is required.

In general, the simultaneous use of multiple drugs should be carefully monitored by a qualified individual such as board certified and licensed medical doctor, either an MD or DO Close association between prescribing physicians and pharmacies, along with the computerization of prescriptions and patients' medical histories, aim to avoid the occurrence of dangerous drug interactions. Lists of contraindications for a drug are usually provided with it, either in monographs, package inserts (accompanying prescribed medications), or in warning labels (for OTC drugs). CDI/MDI might also be avoided by physicians requiring their patients to return any unused prescriptions. Patients should ask their doctors and pharmacists if there are any interactions between the drugs they are taking.

On June 30, 2009, an FDA advisory panel recommended that Vicodin and another painkiller, Percocet, be removed from the market because they have allegedly caused over 400 deaths a year. The problem is with paracetamol (acetaminophen/Tylenol for example ) overdose and liver damage. These two drugs, in combination with other drugs like Nyquil and Theraflu, can cause death by multiple drug intake and/or drug overdose. Another solution would be to not include paracetamol with Vicodin or Percocet.

The National Institute on Drug Abuse (NIDA) says that "even though anabolic steroids do not cause the same high as other drugs, steroids are reinforcing and can lead to addiction. Studies have shown that animals will self-administer steroids when given the opportunity, just as they do with other addictive drugs. People may persist in abusing steroids despite physical problems and negative effects on social relationships, reflecting these drugs’ addictive potential. Also, steroid abusers typically spend large amounts of time and money obtaining the drug; another indication of addiction. Individuals who abuse steroids can experience withdrawal symptoms when they stop taking them, including mood swings, fatigue, restlessness, loss of appetite, insomnia, reduced sex drive, and steroid cravings, all of which may contribute to continued abuse. One of the most dangerous withdrawal symptoms is depression. When depression is persistent, it can sometimes lead to suicidal thoughts. Research has found that some steroid abusers turn to other drugs such as opioids to counteract the negative effects of steroids."

Youth treatment and intervention should focus on eliminating or reducing the effects of adverse childhood experiences, like childhood maltreatment, since these are common risk factors contributing to the early development of alcohol abuse. Approaches like contingency management and motivational interviewing have shown to be effective means of treating substance abuse in impulsive adolescents by focusing on positive rewards and redirecting them towards healthier goals. Educating youth about what is considered heavy drinking along with helping them focus on their own drinking behaviors has been shown to effectively change their perceptions of drinking and could potentially help them to avoid alcohol abuse.

Completely stopping the use of alcohol, or "abstinence," is the ideal goal of treatment. A strong social network and family support maybe important in achieving this goal.

Some people who abuse alcohol may be able to reduce the amount they drink, also called "drinking in moderation." If this method does not work, the person may need to try abstinence. Abstinence has been regularly achieved by many alcoholics in Alcoholics Anonymous.

Mindfulness-based intervention programs (that encourage people to be aware of their own experiences in the present moment and of emotions that arise from thoughts) can reduce the consumption of alcohol.

Preventing or reducing the harm has been called for via increased taxation of alcohol, stricter regulation of alcohol advertising and the provision of brief Interventions. Brief Interventions for alcohol abuse reduce the incidence of unsafe sex, sexual violence, unplanned pregnancy and, likely, STD transmission. Information and education on social norms and the harms associated with alcohol abuse delivered via the internet or face-to-face has not been found to result in any meaningful benefit in changing harmful drinking behaviours in young people.

According to European law, individuals who are suffering from alcohol abuse or other related problems cannot be given a license, or if in possession of a license cannot get it renewed. This is a way to prevent individuals driving under the influence of alcohol, but does not prevent alcohol abuse per se.

An individual's need for alcohol can depend on their family's alcohol use history. For instance, if it is discovered that their family history with alcohol has a strong pattern, there might be a need for education to be set in place to reduce the likelihood of reoccurrence (Powers, 2007). However, studies have established that those with alcohol abuse tend to have family members who try to provide help. In many of these occasions the family members would try to help the individual to change or to help improve the individual's lifestyle.

Male anabolic-androgenic steroid abusers often have a troubled social background.

The distribution of naloxone to injection drug users and other opioid drug users decreases the risk of death from overdose. The Centers for Disease Control and Prevention (CDC) estimates that U.S. programs for drug users and their caregivers prescribing take-home doses of naloxone and training on its utilization are estimated to have prevented 10,000 opioid overdose deaths. Healthcare institution-based naloxone prescription programs have also helped reduce rates of opioid overdose in the U.S. state of North Carolina, and have been replicated in the U.S. military. Nevertheless, scale-up of healthcare-based opioid overdose interventions is limited by providers' insufficient knowledge and negative attitudes towards prescribing take-home naloxone to prevent opioid overdose. Programs training police and fire personnel in opioid overdose response using naloxone have also shown promise in the US.

In the United States there are four approved medications for alcoholism: disulfiram, two forms of naltrexone, and acamprosate. Several other drugs are also used and many are under investigation.

- Benzodiazepines, while useful in the management of acute alcohol withdrawal, if used long-term can cause a worse outcome in alcoholism. Alcoholics on chronic benzodiazepines have a lower rate of achieving abstinence from alcohol than those not taking benzodiazepines. This class of drugs is commonly prescribed to alcoholics for insomnia or anxiety management. Initiating prescriptions of benzodiazepines or sedative-hypnotics in individuals in recovery has a high rate of relapse with one author reporting more than a quarter of people relapsed after being prescribed sedative-hypnotics. Those who are long-term users of benzodiazepines should not be withdrawn rapidly, as severe anxiety and panic may develop, which are known risk factors for relapse into alcohol abuse. Taper regimes of 6–12 months have been found to be the most successful, with reduced intensity of withdrawal.

- Acamprosate may stabilise the brain chemistry that is altered due to alcohol dependence via antagonising the actions of glutamate, a neurotransmitter which is hyperactive in the post-withdrawal phase. By reducing excessive NMDA activity which occurs at the onset of alcohol withdrawal, acamprosate can reduce or prevent alcohol withdrawal related neurotoxicity. Acamprosate reduces the risk of relapse amongst alcohol dependent persons.

- Disulfiram (Antabuse) prevents the elimination of acetaldehyde, a chemical the body produces when breaking down ethanol. Acetaldehyde itself is the cause of many hangover symptoms from alcohol use. The overall effect is severe discomfort when alcohol is ingested: an extremely fast-acting and long-lasting uncomfortable hangover. This discourages an alcoholic from drinking in significant amounts while they take the medicine.

- Naltrexone is a competitive antagonist for opioid receptors, effectively blocking the effects of endorphins and opioids. Naltrexone is used to decrease cravings for alcohol and encourage abstinence. Alcohol causes the body to release endorphins, which in turn release dopamine and activate the reward pathways; hence when naltrexone is in the body there is a reduction in the pleasurable effects from consuming alcohol. Evidence supports a reduced risk of relapse among alcohol dependent persons and a decrease in excessive drinking. Nalmefene also appears effective and works by a similar manner.

- Calcium carbimide works in the same way as disulfiram; it has an advantage in that the occasional adverse effects of disulfiram, hepatotoxicity and drowsiness, do not occur with calcium carbimide.

The Sinclair method is a method of using naltrexone or another opioid antagonists to treat alcoholism by having the person take the medication about an hour before they drink alcohol, and only then. The medication blocks the positive reinforcement effects of ethanol and hopefully allows the person to stop drinking or drink less.

Evidence does not support the use of selective serotonin reuptake inhibitors (SSRIs), tricyclic antidepressants (TCAs), antipsychotics, or gabapentin.

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.