Robinson and his colleagues have investigated

 depressive symptoms following stroke in both right and left

 hemisphere patients. In two studies, Robinson and Price

 (1982) and Robinson et al. (1984) found that patients with

 left hemisphere strokes were more depressed than patients

 with right hemisphere strokes. Starkstein, Robinson, and

 Price (1987) also noted that right hemisphere patients were

 indifferent and sometimes euphoric immediately following

 stroke. Additionally, Robinson and Szetela (1981) reported

 that patients with traumatic brain injury, while equally as

 impaired cognitively and physically, were not as depressed

 as stroke patients. Consequently, frequency and severity of

 depression is not solely related to amount of physical and

 cognitive impairment.

 Differences in mood depending on caudality (anterior

versus posterior location) of the lesions were also observed

(Robinson et al., 1984). The left anterior group showed

significantly more overall depression than the left

posterior group, whereas the right posterior group were more

depressed than right anterior group. Similarly, Starkstein

et al. (1987) reported that when depression was present in

RHD patients, it was associated with parietal lesions.

Additionally, depression was found to be correlated with

closeness of the lesion to the frontal pole (Robinson &

Szetela, 1981; Starkstein, Robinson, and Price, 1987).