The Diagnostic and Statistical Manual (DSM) is used by mental health professionals for diagnosing and assigning psychological disorders. Within the DSM is a section on personality disorders. Personality disorders can be thought of as extremely unhealthy examples of the personality types. Personality types may reveal characteristics similar to the personality disorders but to a much less dysfunctional degree.
In one of his books, Claudio Naranjo associated the DSM III personality disorders with the nine Enneagram types. These do not match the types 100%. Some types are closer matches than others. Interestingly, he didn't find a match for type 3 (suggesting that might have to do with the encouragement of that type in American culture). Other authors and teachers may match the disorders to the types differently.
Type 2: Histrionic Personality Disorder
Type 3: Not Found (Fromm's Marketing Orientation)
Type 5: Schizoid Personality Disorder
Type 9: Dependent Personality Disorder