In 1962 Meehl furthered Rados theory through the introduction of the concept of schizotaxia, a genetically driven neural integrative defect thought to give rise to the personality type of schizotypy. Loren and Jean Chapman further distinguished between two types of anhedonia: physical anhedonia, or a deficit in the ability to experience physical pleasure, and social, or a deficit in the ability to experience interpersonal pleasure.Recent research suggests that 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. These findings provide support for the conjecture that it represents a genetic risk marker for schizophrenia-spectrum disorders. Additionally, elevated levels of social anhedonia in patients with schizophrenia have been linked to poorer social functioning. Socially anhedonic individuals perform worse on a number of neuropsychological tests than non-anhedonic participants, and show similar physiological abnormalities seen in patients with schizophrenia. Comorbidity
Anhedonia is present in several forms of psychopathology. Depression
Social anhedonia is observed in both depression and schizophrenia. However, social anhedonia is a state related to the depressive episode and the other is trait related to the personality construct associated with schizophrenia. These individuals both tend to score highly on self-report measures of social anhedonia.
Blanchard, Horan, and Brown demonstrated that, although both the depression and the schizophrenia patient groups can look very similar in terms of social anhedonia cross-sectionally, over time as individuals with depression experience symptom remission, they show fewer signs of social anhedonia, while individuals with schizophrenia do not. Blanchard and colleagues (2011) found individuals with social anhedonia also had elevated rates of lifetime mood disorders including depression and dysthymia compared to controls. Social anxiety
As mentioned above, social anxiety and social anhedonia differ in important ways. However, social anhedonia and social anxiety are also often comorbid. People with social anhedonia may display increased social anxiety and be at increased risk for social phobias and generalized anxiety disorder. It has yet to be determined what the exact relationship between social anhedonia and social anxiety is, and if one potentiates the other. Individuals with social anhedonia may display increased stress reactivity, meaning that they feel more overwhelmed or helpless in response to a stressful event compared to control subjects who experience the same type of stressor. This dysfunctional stress reactivity may correlate with hedonic capacity, providing a potential explanation for the increased anxiety symptoms experienced in people with social anhedonia. In an attempt to separate out social anhedonia from social anxiety, the Revised Social Anhedonia Scale didnt include items that potentially targeted social anxiety. However, more research must be conducted on the underlying mechanisms through which social anhedonia overlaps and interacts with social anxiety.