182 Depressive Disorders
some cases, onset of the depression is weeks to months following the CVA. In the largest
series, the duration of the major depressive episode follo wing stroke was 9–11 months on
average. Similarly, in Huntington’s disease the depressive state comes quite early in the
course of the illness. With Parkinson’s disease and Huntington’s disease, it often precedes
the major motor impairments and cognitive impairments associ ated with each condition.
This is more prominently the case for Huntin gton’s disease, in which depression is con-
sidered to be the first neuropsychiatric symptom. There is some observational evidence
that depression is less common as the dementia of Huntington’s disease progresses. 
Risk and Prognostic Factors
The risk of acute onset of a major depressive disorder following a CVA (within 1 day to a
week of the event) appears to be strongly correlated with lesion location, with greatest risk
associated with left frontal strokes and least risk apparently associated with right frontal
lesions in those individuals who present within days of the stroke. The association with
frontal regions and laterality is not observed in depressive states that occur in the 2–6 months
following stroke.
Gender-Related Diagnostic Issues
Gender differences pertain to those associat ed with the medical condition (e.g., systemic
lupus erythematosus is more common in fema les; stroke is somewhat more common in
middle-age males compared with females).
Diagnostic Markers
Diagnostic markers pertain to those associated with the medical condition (e.g., steroid
levels in blood or urine to help corroborate the diagnosis of Cushing’s disease, which can
be associated with manic or depressive syndromes).
Suicide Risk
There are no epidemiological stud ies that provide evidence to differentiate the risk of sui-