Aetiology and Pathology exist in DSM-IV
Alan Dugdale’s letter in the 08 January edition of BMJ, ‘Rationale for Psychostimulants in ADHD,’ has several items that may require a second -look. (1) Dr. Dugdale’s makes an unsupportable claim when he states that all the DSM -IV definitions are syndromes that are “unrelated to pathology and aetiology.” The DSM-IV, the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, published by the American Psychiatric Association, has numerous diagnoses defined on the basis of specific etiology and pathophysiology. (2) A few examples include:
• Substance disorders, i.e. use, abuse and dependence of addictive substances, and their related disorders. These diagnoses have identifiable aetiologies and pathophysiologies, a partial list that includes: Alcohol- induced disorders; amphetamine intoxication delirium; cannabis-induced anxiety disorder; cocaine withdrawal; hallucinogen-induced psychotic disorder; nicotine dependence, opioid intoxication and others.
• Dementias with identifiable aetiology and pathology include: Dementia due to HIV/AIDS, head trauma, Parkinson’s disease, dementia of the Alzheimer’s type, Huntington’s disease, Pick’s disease, vascular dementia and others.
• Certain sexual disorders: Hypoactive sexual disorders due to testosterone deficiency; or estrogen deficiency; or psychoactive-induced sexual dysfunction.
• The realm of childhood disorders with identifiable aetiology and pathophysiology include: Tourette’s syndrome, expressive language disorder or childhood or delayed posttraumatic stress responses related to abuse, neglect or sexual assault.
There are certain DSM-IV disorders that are, in my opinion, so descriptive that they may therefore fall into a group that Dr. Dugdale identifies: Oppositional-defiant disorders, conduct disturbances, certain very short-lived depressive responses, eating disorders not otherwise specified (i.e., not anorexia nor bulimia) and certain disorders of impulse control. These, and other diagnoses, may constitute a group in which either the etiology or the pathology/pathophysiology is insufficiently defined. Despite the ‘syndromal’ aspects of some DSM-IV diagnoses, definitions that define medical problems without obvious etiology or pathology are not solely an issue for psychiatric diagnosis. Headaches, fatigue, and pain are but three of the medical ‘diagnoses’ for which much is prescribed--- but, on a case by case basis---little may be known in regard to etiology or pathology.
Dr. Dugdale ends his letter by suggesting that a separation of attentional problems into biochemical disorders and clinical syndromes may promote a rational use of psychostimulants. As a psychiatrist and addictionologist, I would personally like nothing better than to see a more rational basis for the prescriptions of stimulants. Unfortunately, we are not yet at the point where clinicians can separate the attention deficit ‘groups’ into specific diagnostic categories. The available science is not yet up to the task. However, we can proceed more cautiously and rigorously attempt to isolate and only treat those attention deficit cases where the clinical evidence is overwhelming and challenge-re-challenge trials and drug-holidays continue to confirm the clinical syndrome.
(1) Dugdale, A. Rationale for psychostimulants in ADHD BMJ 2005; 330: 95-b
(2) American Psychiatric Association: Diagnostic and Statistical Manual of Mental Disorders. Fourth Edition. Washington, DC, American Psychiatric Association, 1994.
Competing interests: None declared
Competing interests: No competing interests