What is Anhedonia?
Anhedonia is a condition in which a person is unable to take pleasure in activities or situations they once enjoyed. It is a common symptom of depression but also a feature of many other brain-related disorders.
Scientists don’t yet know what causes anhedonia. It is likely related to the brain circuitry that processes rewards, but the precise neurological nature of the condition is elusive. Because of this, treatment of the condition can be challenging.
Symptoms of Anhedonia
Symptoms of anhedonia appear in many different brain disorders, most notably major depression. However, people with anhedonia are not always depressed, and sometimes it can be associated with physical disorders such as Parkinson’s disease or diabetes.
Symptoms can vary in intensity, from a complete loss of enjoyment to a partial dulling of pleasurable feelings associated with positive activities.
Common symptoms of anhedonia include:
- Loss of interest in activities or hobbies that you used to enjoy
- Loss of interest in social activities
- Loss of enjoyment of food
- Loss of interest in personal relationships
- Decreased sex drive
Types of Anhedonia
Some scientists believe that anhedonia can be categorized into two different types depending on the nature of the symptoms; however, the validity of this division is still a matter of debate. The two types of anhedonia are:
- Social anhedonia is the loss of interest in social activities, relationships, and situations involving other people.
- Physical anhedonia is the loss of interest in activities involving physical sensations, such as eating and sex.
What Causes Anhedonia?
Doctors and researchers have not yet determined precisely what causes anhedonia, and there are likely several factors that lead to the onset of the disorder in most cases. It is probably associated with problems in the parts of the brain responsible for reward-seeking and motivation.
Anhedonia is also likely linked to the levels or functioning of a brain chemical called dopamine. Dopamine is part of the brain’s pleasure-reward system. It is also associated with some brain disorders, such as Parkinson’s disease, which might explain why anhedonia is sometimes associated with these disorders.
Is Anhedonia Hereditary?
It’s unclear whether anhedonia has an inherited component, but some brain disorders of which anhedonia is a symptom, including depression, seem to be linked to genetic traits. Studies of families where major depressive disorder occurs strongly suggest that a genetic component may be a critical factor in the development of the condition.
- Some studies have found that when one twin has the disorder, the other twin also has the condition at a rate of as much as 38%.
- Two studies have found that women seem much more likely to inherit the disorder than men. The studies showed that women seem to inherit the condition at a rate of about 40%, while men inherit it at a rate of about 30%.
How Is Anhedonia Detected?
Although anhedonia is not always associated with depression, anhedonia can produce signs and symptoms that are often warning signs of depression. Potential signs of anhedonia include:
- Withdrawal from social activities
- Change in sex drive
- Substance abuse
- Decline in performance at work or school
How Is Anhedonia Diagnosed?
Diagnosis of anhedonia typically begins with a physical assessment followed by a psychological evaluation. First, doctors will usually make an effort to rule out medical conditions that could be causing the physical and mental symptoms. After these potential physical conditions have been ruled out, the diagnostic process will move on to possible psychological causes.
Diagnostic steps may include:
- A physical exam. This exam aims to rule out physical conditions that could be causing the symptoms.
- Blood and laboratory tests. These tests will look at the patient’s blood chemistry for issues such as thyroid function that could be causing the symptoms of anhedonia. Screenings for drugs and alcohol may also be conducted to rule out symptoms caused by substance abuse.
- Psychological assessments. These assessments may take the form of questionnaires or talk sessions with a mental health professional to assess the patient’s mood, mental state, and mental health history. Family members or caregivers may also be asked to participate in these assessments.
A psychiatrist or psychologist will compare the results of the psychological assessments to the diagnostic criteria for major depression and other disorders in the Diagnostic and Statistical Manual of Mental Disorders. Comparing these criteria will help the psychiatrist decide whether the symptoms indicate depression, another psychiatric problem, or a coincidence of depression and another condition.
How Is Anhedonia Treated?
The treatment prescribed for anhedonia depends on the severity of the symptoms, the medical history of the patient, and any underlying physical or psychological conditions that contribute to the symptoms of the disorder. Treating associated disorders such as Parkinson’s disease may help relieve anhedonia.
Aside from treating any underlying disorders, the treatment for anhedonia often includes antidepressant medication, psychotherapy, or both.
Antidepressants, including selective serotonin reuptake inhibitors (SSRIs), are often used to treat anhedonia, primarily when it manifests as a symptom of depression. The effectiveness of SSRIs in improving anhedonia is mixed, and some people report that antidepressants make their anhedonia symptoms worse.
Some recent studies suggest that the drug ketamine may improve symptoms of depression, including anhedonia.
The most common therapeutic approaches used to treat anhedonia and depression are cognitive behavioral therapy (CBT) and interpersonal therapy (IPT). CBT focuses on helping the patient identify a pattern of harmful thoughts and construct strategies and solutions for dealing with them that don’t interfere with functionality. IPT helps the patient understand interpersonal relationships’ challenges and find solutions to the problems.
Therapies sometimes used to treat depression or anhedonia that don’t respond to medication or psychotherapy include:
- Vagus nerve stimulation (VNS)
- Transcranial magnetic stimulation (TMS)
- Electroconvulsive therapy (ECT)
How Does Anhedonia Progress?
In some cases, anhedonia can resolve independently, but it and other symptoms of depression are very likely to recur in most people. Left untreated, depressive symptoms can become more severe and result in significant complications, including:
- Weight gain and its consequences
- Substance abuse
- Anxiety disorders
- Panic disorders
- Relationship dysfunction
- Employment or school dysfunction
- Social anxiety
How Is Anhedonia Prevented?
There is no known way to prevent anhedonia.
Anhedonia Caregiver Tips
As with major depression and other depressive disorders, those who care for sufferers of anhedonia are at risk of developing depression themselves. Caregivers for someone with anhedonia should consider these tips to help the sufferer and themselves deal with the disorder:
- Learn as much as possible about the disorder.
- Don’t expect the sufferer to get better on their own.
- Seek appropriate professional treatment for the sufferer.
- Do everything possible to support the sufferer in the pursuit of treatment.
- Be supportive of the sufferer and acknowledge any improvements.
- Find a support group for caregivers.
- Take time away from the sufferer when possible.
Many people with anhedonia also suffer from other brain and mental health-related issues, a situation called co-morbidity. Here are a few of the disorders commonly associated with anhedonia:
Anhedonia Brain Science
Scientists are interested in better understanding the brain function and chemistry involved in anhedonia to facilitate the development of effective medications, particularly for those who don’t respond well to existing drugs.
- Researchers using imaging technologies have shown people with anhedonia seem to have lower than normal activity in specific brain areas, including the nucleus accumbens, ventromedial prefrontal cortex, and orbitofrontal cortex.
- The functionality of the neurotransmitter chemical dopamine seems to play a significant role in anhedonia; it is hypothesized that other neurochemicals are involved as well.
- The Food and Drug Administration has recently approved the anesthetic ketamine as a treatment for major depression. Scientists have developed a form of the well-established drug administered via a nasal spray; the treatment shows promise for treating the symptoms of medication-resistant depression, including anhedonia.
Title: Development of a Novel Transdiagnostic Intervention for Anhedonia – R33 Phase
Principal Investigator: Gabriel S. Dichter, PhD
University of North Carolina
Chapel Hill, NC
The aim of this project is to develop a novel transdiagnostic treatment for anhedonia, called Behavioral Activation Treatment for Anhedonia (BATA), using ultra-high field functional neuroimaging. There is a critical need for a validated treatment that specifically targets anhedonia, and this project will evaluate the effects of this new treatment on anhedonia. It will establish how this treatment impacts brain systems that mediate reward processing, clinical symptoms of anhedonia, functional outcomes, and behavioral indices of reward processing. This work will also identify brain targets by which future novel anhedonia treatments may be evaluated.
Deficits in motivation and pleasure, together referred to as anhedonia, are implicated in several psychiatric illnesses, including mood and anxiety disorders, substance-use disorders, schizophrenia, and attention-deficit/hyperactivity disorder. As a result, constructs related to anhedonia are central to the NIMH Research Domain Criteria (RDoC) project. Anhedonia is often one of the most difficult psychiatric symptoms to treat and thus represents a critical endophenotype and vulnerability factor for a range of psychiatric disorders. Given the centrality of anhedonia to a large number of psychiatric disorders, improved interventions to treat motivation and pleasure are critical for these disorders. This R61/R33 project aims to develop a novel transdiagnostic treatment for anhedonia called Behavioral Activation Treatment for Anhedonia (BATA). This new intervention is designed to treat anhedonia by emphasizing supported engagement with personally relevant goals and reducing avoidance behaviors. Consistent with the objectives and milestones outlined in RFA-MH-16-406 (“Exploratory Clinical Trials of Novel Interventions for Mental Disorders”), in the R61 phase of this trial that lasted from June 22, 2017-July 31, 2019, the investigators proposed to use an experimental therapeutics approach to first evaluate mesocorticolimbic target engagement by this treatment in a transdiagnostic sample characterized by clinically impairing anhedonia (Aim 1). Specifically, the investigators examined the effects of this treatment, relative to an active comparison treatment, on caudate nucleus activation during reward anticipation and rostral anterior cingulate cortex activation during reward outcomes using ultra-high field (7T) functional magnetic resonance imaging. The investigators also used fMRI to determine the optimal dose of the intervention (Aim 2).
In the current R33 phase of the study, the investigators plan to evaluate the effects of the optimal dose of this new treatment, versus an active comparison treatment, on anhedonic symptoms and functional outcomes (Aim 3), behavioral indicators of reward sensitivity (Aim 4), and neural indicators of reward processing (Aim 5).
Title: Anhedonia, Development, and Emotions: Phenotyping and Therapeutics (ADEPT)
Principal Investigator: Erika E. Forbes, PhD
University of Pittsburgh
The goal of the ADEPT Study is to understand anhedonia in young people and how it changes based on treatments targeting the brain circuit underlying it. Anhedonia is a challenging mental health symptom that involves difficulty with motivation to experience pleasant events. This study could help develop treatments for people whose depression does not improve with traditional treatments.
The ADEPT Study includes two phases. In Phase 1, participants are asked to go through a series of activities to measure anhedonia, including MRI scans, blood draws, behavioral tasks, clinical interviews, questionnaires, and app-based assessments of experiences and behaviors. Phase 2 involves therapeutic activities, such as transcranial magnetic stimulation (TMS), positive affect training, and, for some people, ketamine administration. If the participant qualifies and is interested, they may choose to do Phase 2 activities in addition to Phase 1.
Title: Developing Brain Imaging Analysis Expertise for Personalizing Transcranial Electric Stimulation in Anhedonia Treatment of Patients With Bipolar Depression
Stage: Not Yet Recruiting
Principal Investigator: Jair C. Soares, MD, PhD
The University of Texas Health Science Center
The purpose of this study is to investigate whether transcranial direct-current stimulation (tDCS) will engage reward-related brain circuitry, more specifically, the uncinate fasciculus (UF) tract, which connects the orbitofrontal cortex (OFC) and nucleus accumbens (NAcc) regions. The study will also evaluate whether the changes in the fractional anisotropy (FA) of the UF tract are associated with changes in clinical symptoms of anhedonia. Finally, the study will investigate the moderation role of simulated electric fields (EFs) in an association between FA of the UF and symptoms of anhedonia.