Just about everyone goes through periods when it is difficult to experience happiness or feel joy, but what many people don’t know is that this phenomenon is called anhedonia, and is a common symptom associated with schizophrenia and depression.
Often, this is due to external factors such as overwhelming stress, relationship problems, or a significant loss. Sometimes, it can be symptomatic of a depressive disorder or another mental illness.
For example, the list of criteria for major depressive disorder in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) includes “markedly diminished interest or pleasure in all, or almost all activities most of the day, nearly every day.”
Clinicians refer to this experience as anhedonia. Anhedonia is symptom of schizophrenia and depression, and is also associated with:
- Anxiety disorders
- Bipolar disorder
- Posttraumatic stress disorder (PTSD)
- Substance misuse and addiction
Though anhedonia is linked with some of the most prevalent mental and behavioral health disorders, it is far from a fully understood phenomenon. However, ongoing research efforts have allowed experts to develop greater insights into the causes and effects of anhedonia, particularly among people who have schizophrenia and depression.
What Is Anhedonia?
As noted at the beginning of this post, anhedonia describes a lack of interest in and an inability to derive pleasure from virtually every aspect of daily life. But it’s actually more than that.
If someone with no clinical background were asked to describe what depression feels like, there is a good chance that their answer might include some of the following difficulties, which are also descriptions of anhedonia:
- Pervasive sense of sadness
- Lack of desire to associate with other people
- Getting no happiness in activities that used to be sources of great joy to them
- Diminished appetite (often because food simply doesn’t taste good anymore)
- Having no interest in or receiving no pleasure from sex
This extended description of anhedonia is supported by a July 2019 study in the journal European Child and Adolescent Psychiatry on children that did not have schizophrenia but did have depression. This study reported that this symptom can be characterized by the following changes and emotions:
- Loss of positive affect
- Blunting of emotions
- No drive or willingness to exert effort
- Social withdrawal
- No sense of purpose
Now that we have established a more thorough understanding of what anhedonia feels like, we can turn our attention toward how it affects people who have depression and schizophrenia.
Anhedonia & Depression
Diego A. Pizzagalli, PhD, explored the relationship between anhedonia and depression in a July 2022 article in The American Journal of Psychiatry. Pizzagalli’s article included the following facts:
- As many as 72% of people who have major depressive disorder (MDD) experience anhedonia.
- Among those with MDD, research connects the presence of anhedonia with poor response to medications, therapy, and neurostimulation treatments.
- Anhedonia increases the likelihood that someone with MDD will die by suicide.
“Treating anhedonia associated with MDD as well as with other neuropsychiatric disorders remains a daunting clinical challenge,” Pizzagalli wrote. “Loss of pleasure, as well as blunted motivation to pursue pleasurable activities and learn from them, negatively impacts our ability to see purpose in life, to function across domains (e.g., family, work, society), and to be resilient when challenged by life stress.”
According to the July 2019 European Child and Adolescent Psychiatry study that we cited in the previous section, researchers who employed functional magnetic resonance imaging (fMRI) and behavioral assessments have discovered that anhedonia can affect people in the following three areas.
The Impact of Anhedonia
- Liking (consummatory/hedonic impact)
- Wanting (anticipatory/motivational impact)
- Learning (impact on reward prediction)
To the authors of the July 2019 study, this indicates that anhedonia among people who have depression is a function of deficiencies in their ability to anticipate and process rewards. The study’s authors noted that deficient reward anticipation has also been cited in neural and behavioral research involving adults.
The profound impact of anhedonia on people with major depressive disorder was also documented in a systematic review and meta-analysis that was published by JAMA Psychiatry in August 2020:
- The JAMA Psychiatry investigation involved data from 168 studies and more than 16,000 individuals.
- The general goal of this effort was to assess differences in anhedonia among people with various physical and mental health concerns.
- Subjects’ experiences with anhedonia were quantified using the Snaith-Hamilton Pleasure Scale (SHAPS).
The team that conducted this meta-analysis found that the severity of anhedonia was “significantly elevated” among people who had the following concerns.
Anhedonia, Mental Health, and Physical Pain
- Major depressive disorder
- Substance use disorders
- Parkinson’s disease
- Chronic pain
Among people with these disorders, those with MDD scored “considerably higher” on the SHAPS, the researchers reported, which indicates a signifcant impact.
“Whereas anhedonia in MDD affects multiple pleasure domains, patients with other conditions may experience decreased enjoyment of only a minority of life’s many rewards,” they wrote.
Anhedonia & Schizophrenia
The authors of the JAMA Psychiatry review in the previous section wrote that patients with schizophrenia are likely to experience “moderate anhedonia.” Other researchers have determined that the impact of anhedonia on those with schizophrenia may be more significant.
According to a June 2022 study in the journal Neuropsychiatric Disease and Treatment, anhedonia may affect as many as 80% of people who have schizophrenia.
Though we typically view anhedonia in the context of the negative symptoms of schizophrenia, the authors of the June 2022 study linked it to disrupted cognition and deficits in reward processing. The researchers found that, among people with schizophrenia, presence of anhedonia correlates with dysfunctional aversion circuits. These systems of neurons influence the ability to predict both rewards and negative responses.
The June 2022 study included the following findings related to brain functioning among people with schizophrenia and anhedonia:
- Anhedonia: possibly be the result of impairments in the brain’s ability to determine the value of rewarding experiences.
- People with schizophrenia show “relatively strong aversive emotions” toward stimuli that people without schizophrenia rate as neutral or pleasant.
- Neuroimaging studies indicate that schizophrenia patients show lower gray matter volume in certain areas of the brain, as well as “enhanced functional coupling” between areas associated with reward.
- Aberrant brain functioning: possibly linked with feedback-processing deficits in patients with schizophrenia.
The authors of this study identified neurocognitive impairments as a likely cause of anhedonia among individuals with schizophrenia. They also linked the motivational deficits characteristic of both schizophrenia and anhedonia with brain aberrations that compromise the ability to make appropriate judgements on the salience of various inputs.
Treatment for Anhedonia
In addition to documenting the prevalence and impact of anhedonia among people with major depressive disorder and schizophrenia, research in this area shows potential shortcomings in treatment, especially as related to prescription medication:
- The authors of the June 2022 Neuropsychiatric Disease and Treatment study noted that neither typical nor atypical antipsychotics demonstrate an ability to achieve “clinically significant improvement” of anhedonia among people who have schizophrenia.
- They also reported that selective serotonin reuptake inhibitors (SSRIs) and other typical first-line antidepressants do not alleviate anhedonia among people who have MDD.
On a more hopeful note, the June 2022 research team indicated that ketamine has shown promise at alleviating anhedonia among people with MDD. Several other researchers have also singled out ketamine for its effectiveness at helping people overcome anhedonia.
For example, researchers noted the potential benefits of ketamine in an October 2021 research article in Frontiers in Psychiatry. That article reported that ketamine infusions led to the following outcomes among subjects who had either MDD or bipolar disorder:
- Decreased anhedonia
- Significant reduction in SHAPS score
- Diminished suicidal ideation
- Reduction of depressive symptoms
One caution in this study is that patients on benzodiazepines (which can alleviate some manic symptoms of bipolar disorder) did not appear to benefit from ketamine infusions to address anhedonia.
A March 2022 review in the journal Psychopharmacology echoed these findings. The authors of this review, which evaluated prior research into ketamine’s benefits for people with anhedonia, described the medication as “an effective and rapid-acting therapeutic in an unmet domain.”
The review’s authors also reported that studies on ketamine reveal “a trend towards symptom reduction and/or improvements in anhedonia … as well as its potential to provide additional benefit in reducing suicidality and improving quality-of-life.”
Learn More Today
Depression and schizophrenia are complex mental health concerns that often require innovative services and dynamic solutions. At Crownview Psychiatric Institute in Oceanside, California, our approach includes customized clinical care, focused educational opportunities, and true wraparound support, all within a welcoming community-like environment.
Depending on the unique needs and goals of each person who heals with us, we may incorporate ketamine treatment and a host of additional adjunctive services into their individualized plan.
To learn more about how we help adults who have been living with depression, schizophrenia, or other complex mental health disorders, please visit our Contact page or call our center today.