Did brain trauma lead to crime?
Mr. P pleads not guilty to rape charges, claiming a head injury 8 years ago caused personality changes, psychosis, and violent behavior. Is he malingering?
EVALUATION: Vague answers
To determine whether Mr. P’s defense is plausible, the forensic psychiatrist must pay attention to the details of the patient’s presentation and history. During the interview, Mr. P quickly shifts from cooperative to obstinate and restricted. He ruminates on the head injury causing him to suffer auditory hallucinations, which he claims he always obeys. Mr. P refuses to provide details of the hallucinations, however, and answers most questions about the head injury or his defense with vague answers, including “I don’t know.”
Because of Mr. P’s reluctance to share information, his lack of psychiatric symptoms other than those he self-reports, and the presence of potential secondary gain from an NGRI defense, the psychiatrist begins to suspect malingering.
The authors’ observations
Malingering is a condition—not a diagnosis—characterized by intentional production of false or grossly exaggerated physical or psychological symptoms motivated by external incentives.11 The presence of external incentives distinguishes malingering from psychiatric illnesses such as factitious and somatoform disorders, in which there is no apparent external incentive. Malingering of psychiatric symptoms occurs in up to 20% of forensic patients, 5% of military recruits, and 1% of mental health patients.5 Stimuli for malingering range from seeking food and shelter to avoiding criminal responsibility ( Table 2 ). Malingering is more common in individuals being evaluated for criminal responsibility than for competence to stand trial. The 3 categories of malingering are:
Table 2
Common external incentives for malingering
| Evading criminal responsibility |
| Disability claims/financial gain |
| Avoiding military duty |
| Evading work |
| Obtaining drugs |
| Seeking food/shelter |
- pure malingering—feigning a nonexistent disorder
- partial malingering—consciously exaggerating real symptoms
- false imputation—ascribing real symptoms to a cause the individual knows is unrelated to the symptoms.12
Determining if a defendant with a history of TBI is malingering requires a multi-step approach that encompasses the clinical interview, a thorough review of collateral data, and focused psychological testing. In interviews, psychiatrists detect approximately 50% of lies, which is no better than would be discovered by chance.13 If you suspect a patient is malingering, combine a structured clinical interview with collateral sources such as old hospital records, treatment history, insurance records, police reports, and interviews with close family and friends.
TBI patients’ poor cognition, memory deficits, and inattention will prove challenging. Malingering patients who attempt to capitalize on a pre-existing TBI to evade responsibility for a current criminal charge may grossly exaggerate or even fake intellectual deficits. Be patient with such defendants and remain aware that such people will give vague or hedging answers to straightforward questions, often accompanied by “I don’t know.” Prolonging the interview may be helpful because it may fatigue a defendant who is faking.12
Some patients who malinger after sustaining a TBI will attempt to feign psychotic symptoms. Table 3 14 illustrates criteria for assessing a patient suspected of malingering psychosis and Table 4 14 highlights atypical psychotic symptoms that suggest feigning illness. Malingering of psychosis can be both assessed in the interview and through testing.
Table 3
Criteria for malingered psychosis
| A. Understandable motive to malinger |
| B. Marked variability of presentation as evidenced by ≥1 of the following: 1. Marked discrepancies in interview and non-interview behaviors 2. Gross inconsistencies in reported psychotic symptoms 3. Blatant contradictions between reported prior episodes and documented psychiatric history |
| C. Improbable psychiatric symptoms as evidenced by ≥1 of the following: 1. Reporting elaborate psychotic symptoms that lack common paranoid, grandiose, or religious themes 2. Sudden emergence of purported symptoms to explain antisocial behavior 3. Atypical hallucinations and delusions |
| D. Confirmation of malingering by either: 1. Admission of malingering following confrontation, or 2. Presence of strong corroborative information, such as psychometric data or history of malingering |
| Source: Reference 14 |
Table 4
Atypical psychotic symptoms that suggest malingering
| Hallucinations |
| Continuous rather than intermittent |
| Vague or inaudible auditory hallucinations |
| Stilted language reported in hallucinations |
| Inability to state strategies to diminish voices |
| Self-report that all command hallucinations were obeyed |
| Visual hallucinations in black and white |
| Delusions |
| Abrupt onset or termination |
| Eagerness to call attention to delusions |
| Conduct markedly inconsistent with delusions |
| Bizarre content without disordered thinking |
| Source: Reference 14 |
Psychological testing
Several standardized diagnostic instruments can be used to help determine whether a patient is feigning or exaggerating psychotic symptoms or cognitive impairments ( Table 5 ). Testing for a patient such as Mr. P—who attributes any criminal wrongdoing to psychosis and also cites limited cognition as a reason for trouble in the interview—would include personality tests, tests to assess exaggerations of psychosis, and cognitive tests.
