On Anhedonia: A Lasting Effect of Addiction

By Laurel Sindewald

Much of the battle of recovery is a hidden, quiet affair. After the shakes subside and a person is considered stable enough to have survived acute withdrawal symptoms, the person in recovery from addiction has a hard slog ahead.

The experience has not been studied enough for it to be considered official, but people who have seen or experienced it have given it a name anyway: post-acute withdrawal syndrome or PAWS. SAMHSA has taken note of the condition and has published an article with helpful details on how PAWS affects people recovering from different substance addictions. Symptoms of PAWS can include depression, anhedonia, loss of concentration, craving, sleep disturbances, stress sensitivity, anxiety, and guilt.

While post-acute withdrawal syndrome has not been studied extensively as a whole, anhedonia is a lasting effect of substance use disorders. Anhedonia refers to a physical loss of one’s ability to experience pleasure. Though drug cues continue to elicit craving and the promise of that elusive pleasure, natural sources of pleasure will feel as if they’ve utterly lost their charms. This condition occurs in several neuropsychiatric disorders, most notably major depression and schizophrenia in addition to substance use disorders. It is unknown what exactly causes anhedonia. Yet whether anhedonia causes addiction, addiction causes anhedonia, or anhedonia is caused by other things than addiction and simply co-occurs with addiction, we know that anhedonia occurs upon abstinence from the addictive substance.

Anhedonia is the result of changes in the dopaminergic mesolimbic and mesocortical reward circuit, involving the ventral tegmental area, the ventral striatum, and part of the prefrontal cortex. The inactivation of dopamine in these areas is proposed to lead to anhedonia, though more research is needed to be certain. A recent study (2012) by Robert Malenka of Stanford University found that the nucleus accumbens, part of the ventral striatum, does not work properly when anhedonia occurs. He found that the melanocortin transmitter may have a more specific and relevant role in producing anhedonia in rats under chronic stress than dopamine.

The evidence of anhedonia’s link to addiction is well documented. One study (2009) presented pleasant pictures to a control group and to a group of people addicted to heroin and found that heroin users had reduced responsiveness to these natural reinforcers, “across a range of psychophysiological measures.” They found that, furthermore, their subjective ratings of the pleasant pictures predicted future heroin use.  Another study (2005) found that anhedonia occurred with withdrawal symptoms and was especially associated with craving.  Other studies have also documented that anhedonia occurs (Cook et al., Zijlstra et al., Hatzigiakoumis et al., Leventhal et al.) and persists (Stevens et al., Martinotti et al.) in people in recovery. Anhedonia is more pronounced in people recovering from multiple addictions, and several studies emphasize that anhedonia is a significant indicator of relapse (Koob and Le Moal, Volkow et al., Garfield et al.).

Anhedonia is known to follow cocaine, amphetamine, tobacco, alcohol, cannabis, and especially opiate substance use disorders, though according to SAMHSA its occurrence and intensity does vary from person to person. It is also documented to be long-lasting, though how long is uncertain. A study (2008) of 102 people diagnosed with alcohol use disorders found that anhedonia persisted for the duration of their 12 month study.

It is likely anhedonia can persist longer than a year, but the duration of the condition has not been investigated. A meta-study (2013) of 32 research articles from three different databases has been conducted, intending to discover the average duration of anhedonia among other questions, but the abstract did not report a single study in which the duration of anhedonia after abstinence was studied.

There are some treatments that have had success in treating anhedonia. fMRI studies of Behavioral Activation, a behavioral therapy used to treat depression, have revealed “BOLD responses of the striatum during reward anticipation,” suggesting that Behavioral Activation therapy may be a helpful treatment.

Pharmacological treatments have been developed, specifically targeting the activation of the dopaminergic reward system. These are commonly psychostimulants, dopamine agonists, and bupropion (a norepinephrine/dopamine reuptake inhibitor), thought most treatments were developed to treat anhedonia in depressed patients rather than specifically substance use disorders. A recent study (2011) by Martinotti et al. found that intravenous administration of the drug Acetyl-l-Carnitine accelerated the improvement of anhedonia in detoxified alcohol dependent subjects. Martinotti et al. (2009) also found that aripiprazole was as efficacious as naltrexone in reducing craving in alcohol dependent subjects, and more effective at treating anhedonia. Subjects receiving aripiprazole also remained abstinent for longer periods of time than those receiving naltrexone. More tentatively, in 2008 Martinotti et al. found that the drug quetiapine decreased alcohol consumption, craving, and psychiatric symptoms such as anhedonia in alcohol dependent subjects with comorbid mood disorders.

Even more encouraging, Robert Malenka has had a breakthrough in research regarding anhedonia, which may lead to better pharmacological treatments in the future. He studied rats that had been kept under conditions of chronic stress and who had shown a reduction in preference of sugar water over regular water, as well as significant weight loss. The rats’ conditions improved after he inhibited the release of melanocortin, a transmitter that functioned to reduce the activity of neurons in the nucleus accumbens during periods of chronic stress.

For those who prefer alternative therapies, clinical trials are reported to be underway for the effectiveness of acupuncture in treating drug addiction by influencing the reward system. It is yet to be seen whether acupuncture can be demonstrated to help anhedonia.

Exercise may be beneficial as physical activity has been shown to be inversely related to both depression and anhedonia and regular exercise reduces anhedonia and depression. Regular exercise and a diet tailored to recovery from the drug of abuse may be two immediate treatments for anhedonia, and likely for other PAWS symptoms as well. As research on the exact mechanisms behind anhedonia continues, treatments will undoubtedly improve.

Laurel Sindewald is a writer, researcher, and editor.

The content of this post is for informational purposes only and is not a substitute for medical or professional advice. Consult a qualified health care professional for personalized medical and professional advice.

This post was last updated on 10/20/16.

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Comments

  1. Great read. As a sufferer of anhedonia it is inspiring to know there is at least some light being shed on this area of study. Research in this area could help so many of my generation and i know i can speak for us in saying we are greatful to any and everyone making advances in this area of study.

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