Anhedonia

[an-hee-doh-nee-uh]

In psychology, anhedonia (< Greek αν- an-, without + ηδονή hēdonē, pleasure ) is an inability to experience pleasure from normally pleasurable life events such as eating, exercise, and social or sexual interaction.

Anhedonia is recognized as one of the key symptoms of the mood disorder depression according to both the Diagnostic and Statistical Manual of Mental Disorders Fourth Edition (DSM IV) and the International Statistical Classification of Diseases and Related Health Problems (ICD). Other than anhedonia, the DSM considers only depressed mood to be a key symptom. The ICD lists both depressed mood and fatigue or loss of energy as the other key symptoms. Anhedonia is also seen in schizophrenic disorders and other mental disorders.

Causes

Researchers theorize that anhedonia may result from the breakdown in the brain's reward system, involving dopamine pathways. Two 2005 studies by Paul Keedwell MD of King's College found that certain sections of the brain in depressed subjects had to work harder to process happy thoughts.

Anhedonia is often experienced by drug addicts following withdrawal; in particular, stimulants like cocaine and amphetamines cause anhedonia and depression by depleting dopamine and other important neurotransmitters. Very long-term addicts are sometimes said to suffer a permanent physical breakdown of their pleasure pathways, leading to anhedonia on a permanent or semi-permanent basis due to the extended overworking of the neural pleasure pathways during active addiction, particularly as regards cocaine and methamphetamine. In this circumstance, activities still may be pleasurable, but can never be as pleasurable to people who have experienced the comparatively extreme pleasure of the drug experience. The result is apathy towards healthy routines by the addict. Extended periods of healthy lifestyles away from active addiction have been shown to reverse these feelings.

Anhedonia may also be an effect of prolonged fatigue.

Significance in depression

As a clinical symptom in depression, anhedonia rates highly in making a diagnosis of this disorder. The DSM describes a "lack of interest or pleasure" but these can be hard to tease apart given that people become less interested in things which do not give them pleasure. The DSM criterion of weight loss is probably related to it and many depressed people with this symptom describe a lack of enjoyment from food.

Sexual anhedonia

Sexual anhedonia is known as 'ejaculatory anhedonia'. This rare condition means that the person will ejaculate with no accompanying sense of pleasure. This condition is most frequently found in males, but women can suffer from lack of pleasure when the body goes through the orgasm process as well.

Sexual anhedonia may be caused by:

Hyperprolactinaemia
Hypoactive sexual desire disorder (HSDD), also called inhibited sexual desire
Low levels of the hormone testosterone
Spinal cord injury
Use (or previous use) of SSRI antidepressants
Fatigue
Physical illness

A urological examination and blood tests can determine the cause of a specific case of sexual anhedonia.

Patients may be prescribed sustained-release bupropion to aid in treatment, because bupropion has been shown to increase sexual desire and intensity of orgasm.