Is Modafinil Addictive?

Modafinil has lower abuse liability than traditional stimulants such as amphetamine and methylphenidate, but addiction and dependence are still possible.

Human laboratory studies have found that modafinil can produce desirable subjective effects and can function as a reinforcer under some conditions. Severe dependence has also been documented after extreme dose escalation.

What Does “Addictive” Mean?

Several related concepts are used when researchers assess whether a drug may become problematic.

Abuse liability refers to characteristics that may make a drug more likely to be used for non-medical effects, including pleasurable or stimulant-like subjective effects.

Reinforcement refers to whether exposure to a drug increases the likelihood that someone will choose or work to receive it again.

Tolerance occurs when a larger dose is needed to produce an effect previously achieved with a smaller dose.

Physical dependence refers to physiological adaptation in which reducing or stopping a drug can produce withdrawal symptoms.

Addiction or substance use disorder involves impaired control over drug use and may include craving, repeated unsuccessful attempts to reduce use, continued use despite harm, or substantial time spent obtaining or using the drug.

Withdrawal refers to symptoms that emerge after reducing or stopping a drug following physiological adaptation. The return of the condition a medication was treating is not necessarily withdrawal.

How Is Modafinil Classified in the US?

The U.S. Drug Enforcement Administration classifies modafinil as a Schedule IV controlled substance.

Schedule IV drugs are considered to have lower abuse potential than substances in Schedules I through III. Amphetamine and methylphenidate are Schedule II controlled substances.

Does Modafinil Have Abuse Potential?

Jasinski (2000) compared modafinil with methylphenidate in 24 men with histories of polysubstance abuse that included cocaine.

Participants received placebo, modafinil at 200, 400 or 800 mg, or methylphenidate at 45 or 90 mg under double-blind conditions.

Participants could distinguish both modafinil and methylphenidate from placebo and reported liking the effects of both drugs. Modafinil therefore produced subjectively desirable effects in this population.

Unlike methylphenidate, modafinil did not produce a significant response on the Amphetamine Scale of the Addiction Research Center Inventory. Its overall subjective profile differed from that of the reference stimulant.

Makris et al. (2007) compared modafinil with d-amphetamine in 11 healthy adults. Modafinil increased some ratings associated with stimulant effects, including scores on the Amphetamine and Morphine-Benzedrine Group scales of the Addiction Research Center Inventory. D-amphetamine produced clearer increases in ratings such as feeling stimulated and liking the drug.

Can Modafinil Be Reinforcing?

Unlike drug-liking measures, reinforcement experiments test whether someone will work to obtain a drug again, a distinction Stoops et al. (2005) examined using modafinil doses of 100, 200 and 400 mg.

Six healthy adults could work to obtain previously sampled doses under two conditions.

In the performance condition, participants knew they would later complete repeated arithmetic tasks. In the relaxation condition, they would spend the session resting in a darkened room.

Under the performance condition, modafinil increased the amount of work participants performed to obtain it in a dose-related manner. The same effect was not observed under the relaxation condition.

By contrast, Vosburg et al. (2010) found no preferential selection of modafinil over placebo in 12 cocaine-experienced participants who sampled modafinil at 200, 400 or 600 mg and then repeatedly chose which capsules they wanted to receive.

Ratings including drug liking, willingness to pay and feeling high also did not show systematic increases with modafinil.

How Does Modafinil Affect Dopamine and Reward Pathways?

Volkow et al. (2009) used positron emission tomography to study 10 healthy men after they received 200 or 400 mg of modafinil.

Modafinil occupied dopamine transporters and increased extracellular dopamine in several brain regions, including the nucleus accumbens, which is involved in reward and reinforcement.

The researchers reported a 19.4% reduction in raclopride binding potential in the nucleus accumbens after modafinil, consistent with increased extracellular dopamine.

This finding establishes that modafinil engages a pathway relevant to abuse liability, but it does not establish how often addiction occurs because the study measured acute dopamine changes and dopamine-transporter occupancy rather than rates of substance use disorder.

Can You Become Dependent on Modafinil?

Alacam et al. (2018) described a 24-year-old man with ADHD who began taking modafinil without medical supervision at 50 mg per day and progressively increased his dose in an attempt to maintain its effects on attention and academic performance.

He reportedly used approximately 300 to 400 mg per day for two years before escalating further. By the time he was assessed, he was taking as much as 5,000 mg per day.

He described needing increasingly large doses to obtain the effects he had previously experienced. Attempts to reduce or stop modafinil were associated with irritability, anxiety, sweating, tremor, fatigue, disturbed sleep, vivid unpleasant dreams and a strong urge to take the drug.

He was admitted to a psychiatric ward with an initial DSM-5 diagnosis of stimulant use disorder. After modafinil was stopped, clinicians observed craving, psychomotor agitation, sweating, tremor and fatigue.

The case documents severe problematic modafinil use in one individual whose dose had escalated to 5,000 mg per day.

Does Modafinil Cause Withdrawal?

The US Modafinil in Narcolepsy Multicenter Study Group conducted a nine-week randomised trial involving 271 people with narcolepsy. Participants received 200 mg of modafinil, 400 mg of modafinil or placebo, followed by a two-week placebo-controlled discontinuation phase involving 240 participants.

After modafinil was discontinued, excessive daytime sleepiness returned to baseline levels in participants who had been receiving the drug.

The researchers did not observe symptoms characteristic of an amphetamine withdrawal syndrome and reported no evidence of dependence during up to nine weeks of treatment at the doses studied.

Because excessive daytime sleepiness returned to baseline rather than being identified as a new withdrawal syndrome, its reappearance does not by itself demonstrate drug withdrawal. A person taking modafinil to control excessive sleepiness may become sleepy again once its wake-promoting effect is removed.

The trial covered nine weeks of therapeutic treatment, so it does not address longer periods of use or prolonged exposure to much higher doses.

What Do We Still Not Know?

There are no large prospective studies designed specifically to establish the incidence of modafinil dependence among long-term users.

The risk after years of continuous treatment therefore remains uncertain.

The available studies also do not establish the long-term dependence risk of repeated self-directed modafinil use for performance enhancement.

Population-level data on sustained supratherapeutic use and progressive dose escalation are similarly limited, making it difficult to estimate how often severe patterns of problematic use occur.

Conclusion

People taking prescribed modafinil should not increase their dose in an attempt to maintain or intensify its effects without medical guidance.

Progressive dose escalation, strong cravings, taking more than prescribed or repeated difficulty cutting down are reasons to discuss modafinil use with a healthcare professional.

References

Alacam, H., Basay, O., Tumkaya, S., Mart, M., & Kar, G. (2018). Modafinil dependence: A case with attention-deficit/hyperactivity disorder. Psychiatry Investigation, 15(4), 424–427. https://doi.org/10.30773/pi.2016.10.25

Jasinski, D. R. (2000). An evaluation of the abuse potential of modafinil using methylphenidate as a reference. Journal of Psychopharmacology, 14(1), 53–60. https://doi.org/10.1177/026988110001400107

Makris, A. P., Rush, C. R., Frederich, R. C., Taylor, A. C., & Kelly, T. H. (2007). Behavioral and subjective effects of d-amphetamine and modafinil in healthy adults. Experimental and Clinical Psychopharmacology, 15(2), 123–133. https://doi.org/10.1037/1064-1297.15.2.123

Stoops, W. W., Lile, J. A., Fillmore, M. T., Glaser, P. E. A., & Rush, C. R. (2005). Reinforcing effects of modafinil: Influence of dose and behavioral demands following drug administration. Psychopharmacology, 182(1), 186–193. https://doi.org/10.1007/s00213-005-0044-1

US Modafinil in Narcolepsy Multicenter Study Group. (2000). Randomized trial of modafinil as a treatment for the excessive daytime somnolence of narcolepsy. Neurology, 54(5), 1166–1175. https://doi.org/10.1212/WNL.54.5.1166

U.S. Drug Enforcement Administration. (2024). Drugs of abuse: A DEA resource guide.

Volkow, N. D., Fowler, J. S., Logan, J., Alexoff, D., Zhu, W., Telang, F., Wang, G.-J., Jayne, M., Hooker, J. M., Wong, C., Hubbard, B., Carter, P., Warner, D., King, P., Shea, C., Xu, Y., Muench, L., & Apelskog-Torres, K. (2009). Effects of modafinil on dopamine and dopamine transporters in the male human brain: Clinical implications. JAMA, 301(11), 1148–1154. https://doi.org/10.1001/jama.2009.351

Vosburg, S. K., Hart, C. L., Haney, M., Rubin, E., & Foltin, R. W. (2010). Modafinil does not serve as a reinforcer in cocaine abusers. Drug and Alcohol Dependence, 106(2–3), 233–236. https://doi.org/10.1016/j.drugalcdep.2009.09.002