Another way of managing in-text citations is to think in terms of narratives and parentheses. Narratives are a part of your text, whereas information in parentheses is there but somewhat hidden.
If the name is part of your narrative cite the year in parentheses.
Although Kessler (2003) found that among epidemiological samples…
In the example below there is no need to put anything in parentheses as the year of publication and the author’s name are part of your narrative.
In 2003, Kessler’s study of epidemiological samples showed that
If the author and year are not part of your narrative, place the name and year separated by a comma in parentheses.
Early onset results in a more persistent and severe course (Kessler, 2003).
When the name and year appear first in parentheses, include the year in subsequent citations within the paragraph.
Early onset results in a more persistent and severe course (Kessler, 2003). Kessler (2003) also found. …
(American Psychological Association, 2010, pp. 174-175)