Anhedonia

Anhedonia refers to deficits in hedonic function, including reduced motivation or ability to experience pleasure.

 

It includes: the inability to experience pleasure, reduced motivation, reduced  wanting, reduced liking and deficits in reinforcement learning.

 

It is associated with depressive disorders, substance-related disorders, psychotic disorders, and personality disorders, where it is defined by either a reduced ability to experience pleasure, or a diminished interest in engaging in pleasurable activities.

 

Anhedonia defined as the reduced ability to experience pleasure, and deficits in multiple facets of reward. 

 

Characterized  by affect blunting, restricted affect, emotional numbing, flat affect , particularly in the context of post-traumatic stress disorders. 

 

Brain regions implicated in anhedonia include the prefrontal cortex, particularly the orbitofrontal cortex (OFC), the striatum, amygdala, anterior cingulate cortex (ACC), hypothalamus, and ventral tegmental area 

 

It is theorized that anhedonia may result from the breakdown in the brain’s reward system, involving the neurotransmitter dopamine. 

 

The process can be characterized as the impaired ability to pursue, experience and/or learn about pleasure.

 

Anhedonia occurs in roughly 70% of people with a major depressive disorder.

 

Anhedonia is a core symptom of major depressive disorders.

Many individuals with this symptom describe a lack of enjoyment of food.

 

Anhedonia is of negative symptoms: including deficits in pleasure and motivation in schizophrenia.

 

Schizophrenia is associated with reduced positive pattern of response to an unexpected reward.

 

Anhedonia is common in patients with a dependence upon a wide variety of drugs, including alcohol, opioids, and nicotine. 

 

It usually becomes less severe over time, but relapse is common.

 

Anhedonia occurs frequently in Parkinson’s disease, with rates between 7%–45% being reported.

 

Sexual anhedonia in males refers to ejaculation with no accompanying sense of pleasure.

 

Women can suffer from lack of pleasure from orgasm process as well.

 

Sexual anhedonia related to,

 

Hyperprolactinaemia

 

Hypoactive sexual desire disorder 

 

Low levels of testosterone

 

Spinal cord injury

 

Multiple sclerosis

 

Use of SSRI antidepressants

 

Use anti-psychotic agents

 

Fatigue

 

Physical illness

 

In sexual anhedonia, bupropion aids in treatment, relieveing sexual dysfunction.

 

Social anhedonia is the presence of disinterest in social contact and a lack of pleasure in social situations.

 

Social anhedonia is characterized by social withdrawal. 

 

Social anhedonia manifests as an indifference to other people, and represents a deficit in the ability to experience pleasure.

 

Social anhedonia is characteristic, as well as a predictor of, schizophrenia spectrum disorders, and is seen as a potential evolution of most personality disorders.

 

Clinically manifests with: decreased ability to experience interpersonal pleasure, social withdrawal/isolation,

 

decreased capacity for social contact/interaction, lack of close friends and intimate relationships, and decreased quality of those relationships,

 

Social anhedonia may represent a prodrome of psychotic disorders.

 

First-degree relatives of individuals with schizophrenia show elevated levels of social anhedonia.

 

Higher baseline scores of social anhedonia are associated with later development of schizophrenia.

 

Anhedonia may,represent a genetic risk marker for schizophrenia-spectrum disorders.

 

Anhedonic patients perform worse on a number of neuropsychological tests than non-anhedonic participants, and show similar physiological abnormalities seen in patients with schizophrenia.

 

Anhedonia is present in several forms of psychopathology: Depression, schizophrenia, social anxiety.

 

Patients  with social anhedonia may have  increased stress reactivity, in response to a stressful event.

 

Social anhedonia is a core characteristic of schizoid behavior,  and contributes to risk for psychosis and schizophrenia.

 

Not all people with schizophrenia display social anhedonia.

 

Patients who have social anhedonia may never be diagnosed with a schizophrenia-spectrum disorder, and It may be a predictor of future schizophrenia-spectrum disorders.

 

Social anhedonia usually manifests in adolescence.

 

There is no  medical treatment for social anhedonia.

 

Social support may also play a valuable role in the treatment of social anhedonia. 

 

Males score higher than females on measures of social anhedonia.

 

It is possible social anhedonia may stem from a genetic vulnerability.

 

Social anhedonia may be linked to dysfunction of reward-related systems in the brain. 

 

The reward-related systems in the brain 

 

is critical for the sensation of pleasure, for the computation of reward benefits and costs, determination of the effort required to obtain a pleasant stimulus, and deciding to obtain that stimulus, and increasing motivation to obtain the stimulus. 

 

The  ventral striatum and areas of the prefrontal cortex, including the orbitofrontal cortex and dorsolateral cortex are critically involved in the experience of pleasure and the hedonic perception of rewards. 

 

The orbitofrontal cortex,  nucleus accumbens, ventral pallidum mediate the hedonic perception of rewards via 

 

neurotransmitter systems, opioid, gamma-Aminobutyric acid and endocannabinoid system.

 

Activity in these areas have been found to be decreased in anhedonic individuals

 

Musical anhedonia occurs in individuals who receive no pleasure from listening to music.