Personal Testing & Interest Inventories
Personality tests are often utilized in the beginning of psychotherapy to clarify diagnosis and/or treatment plan. You may request such testing as well should you have particular questions you would like to explore in this format rather than in therapy.
The most reliable & valid objective personality tests are designed by researchers to identify individual strengths & weaknesses according to patterns observed in item answers given by large groups of people. These large groups are often separated into groups of people with known mental health diagnoses and those without (considered to be normative comparison groups.) Some of these tests are heavily researched over years, between ethnic & cultural groups, & are even re-administered to the same individuals to establish the reliability of results over time. These very well-researched tests are typically controlled & are available only through qualified mental health professionals. If you have further questions, you may find the American Psychological Association’s website very informative.
Similarly, the most valid & reliable interest inventories are designed by researchers to identify patterns of individual likes & dislikes that are associated with particular careers. This is not to be mistaken for a person’s capacity to be successful in that field. Capacity is better reflected by IQ & neuropsychological tests. Interest inventories are better utilized in a personal career selection, which is typically followed by an education in that field (which will often itself identify individual capacity for work in that field.)