Guideline 3: Challenges of the Extremes: The Guarded and the Suggestible Interviewee The validity of the information collected may be seriously compromised in the extreme case of a particularly guarded or suggestible interviewee. At one extreme, the guarded interviewee may not reveal much information, particularly in relation to symptoms. Be cause clinical assessment in psychiatry is dependent to a great degree on self-report, interviews with guarded interviewees may create the false impression that they experience fewer symptoms than they actually do. At the other extreme are the suggestible interviewees, who are easily influenced by the interviewer’s questions and “convinced” that they have experienced symptoms they may never have had, and may therefore be assessed as more symptomatic than they are in actuality. Regardless of which extreme a person represents, the information collected through the interview may not reflect his or her condition in a valid manner.

There are a number of possible solutions to these issues. First, the interviewer can be explicit about the value of eliciting the most valid information and its importance in helping to generate the most beneficial and tailored treatment plan. Second, he or she can gently explore whether the interviewee has understood the questions. Third, once the interviewer identifies such a tendency, he or she should be particularly careful about asking leading questions that imply to the interviewee that there is a “right” answer (which would motivate the guarded interviewee to deny having the symptom, and the suggestible interviewee to become convinced that he or she has it). Finally, it is important that the interviewer use his or her judgment and clinical skills to evaluate whether other sources (including observations within the interview) are in concurrence with the interviewee’s self-report. Guideline 4: Assessing Symptoms Many of the reviewed challenges in collecting reliable information during an interview are intensified when an interviewer tries to elicit information about symptoms. These challenges make it particularly difficult to achieve the primary goal of a diagnostic interview - to assess the interviewee’s symptoms in a reliable manner. In the absence of laboratory test markers and indicators, psychiatric diagnosis depends heavily on self-report, which is subject to many distortions (although it may provide valuable information on subjective experience). Fortunately, the interview’s inherent limitations are also its strength: The complex process and data gathering that get in the way of generating a diagnostic hypothesis may also facilitate it. For instance, by evaluating the content and logical flow of the interviewee’s verbalization, the interviewer may be able to learn about the presence of symptoms such as hallucinations and thought disorganization (e.g.,  loose associations, circumstantiality, and thought blocking). Although delusions may at times be readily assessed because of the interviewee’s preoccupation with the theme or idea, at other times engagement in lengthier discussions is required before the interviewee begins to reveal much about his or her delusional ideas. In addition, observing the interviewee’s behavior and affective expressivity during the interview can help the interviewer detect symptoms such as constricted or inappropriate affect. Finally, the interviewer may ask him- or herself whether he or she is losing track of the point the interviewee is trying to make, which can serve as a useful cue to consideration of different symptoms, such as tangential speech or derailing.