Let’s not abandon separation anxiety disorder in adulthood

Professor Starcevic’s (2013) objections to extending separation anxiety disorder (SAD) to adulthood should not pass without comment. In our response, we confine our remarks to the more important issues he raises:

1. In our view, imposing an arbitrary age limit [18 years in the case of SAD according to the Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV)] is unwise for any disorder unless there are very well-substantiated grounds for so doing. Epidemiological data indicate that age of onset curves for common mental disorders tend to trace a smooth arc, with none ending abruptly at some arbitrary point, and certainly not at 18 years of age; otherwise, we would face the prospect of a Cinderella effect – at the stroke of midnight on the young person’s 18th birthday, SAD symptoms would have to disappear or transform into another disorder.

2. Professor Starcevic (2013) argues that separation anxiety is normative and hence should not be regarded as a pathological response. Does this mean that we should ignore the large numbers of children with SAD who seek assistance at anxiety clinics? In our view, the likelihood that SAD derives from a fundamental survival mechanism (Silove et al., 1995) strengthens the argument for recognizing the extreme case as pathological. There is a long and robust literature examining the possible mechanisms whereby evolutionary survival responses can spill over into psychopathology (e.g. in the development of phobias), SAD being a potentially important example. Moreover, defining the line between normative and pathological is hardly a conundrum limited to SAD; we confront the same problem in differentiating extreme unhappiness from clinical depression, realistic anxiety from generalised anxiety disorder, and even quasi-psychotic phenomena from clinical psychosis.

3. Clinicians identify diagnoses that they are taught to detect. There should be no surprise therefore that the majority of clinicians obediently follow the dictates of the DSM-IV (funding in some countries is fixed to applying DSM-specified criteria), nor that studies based on the existing canon have overlooked or misdiagnosed SAD.

4. Comorbidity is common to all the anxiety subtypes. Understanding the nature of the relationship of disorders that co-occur or follow each other seriatim is the important issue. In our recent research, we have shown that the overlap between adult SAD and agoraphobia (AG) reflects true comorbidity, that is, the co-occurence of the two disorders does not arise primarily because of the sharing of common symptoms (Silove and Marnane, 2013). Evidence from the World Mental Health Survey (Kessler et al., 2011) indicates that the pattern of comorbidity of separation anxiety disorder is similar to that of several other anxiety subtypes. Given the generally earlier age of onset, separation anxiety may be of fundamental importance to understanding the genesis and proliferation of other forms of pathological anxiety, such as AG, over the course of the life cycle. Of course, only longitudinal studies will be able to examine these issues in a more definitive manner.

5. The use of a range of measures to assess the same diagnosis in mental health research is the norm not the exception. The fact that different research groups have applied their own measures of SAD therefore comes as no surprise. In its development, the most commonly used measure, the 27-item self-report Adult Separation Anxiety Questionnaire (ASA-27), was calibrated against a semi-structured clinical interview, the conventional test of validity in the psychiatric literature (Manicavasagar et al., 2003). The ASA-27 has also been shown to converge with a measure developed independently by a separate research group (Cyranowski et al., 2002).

6. In passing, it should be noted that the fifth edition of the DSM (DSM-5) has increased the duration of SAD symptoms to 6 months, a more stringent criterion that should constrain rather than increase the prevalence of the disorder overall.

We feel sure that Professor Starcevic will agree that we should listen to the views of patients when evaluating the utility and salience of diagnosing SAD in adulthood. Judging from the multitude of emails and other communications that we have received over the years, we can only conclude that there are a large number of adults with SAD who are convinced that their core problem has not been recognized by the mental health professionals they have consulted. A search for meaning may motivate some to attach themselves to a new diagnosis, legitimate or otherwise. For most, however, the rich descriptions they have provided in relation to their core SAD symptoms, and their accompanying expressions of despair, leave little doubt that they are suffering from the disorder.

At the same time, patients are not diagnosticians; it is no wonder then that they do not identify SAD on their own – unless they happen to have read the available literature. The sad reality is that both patients and clinicians may be blind to what is wrong, creating a vicious cycle of misdiagnosis and neglect of adult SAD. As Professor Starcevic knows, the first step to developing an effective treatment for a disorder is to establish its nosological status, a process that for adult SAD has been long delayed. No wonder then that there are no effective treatments available.

Under the convenient shadow of anonymity, a reviewer of one of our early papers on the topic accused us of nosological promiscuity in proposing the extension of SAD to a wider age group. In reality, the lifting of the age restriction on the diagnosis of SAD in DSM-5 simplifies rather than complicates the nosology of the anxiety disorders in general – no longer is there a single disorder, SAD, assigned to a separate section of disorders that usually have their onset in childhood and adolescence, the untidy arrangement in DSM-IV. Finally, anxiety studies are able to apply the same diagnostic profile to children, adolescents and adults alike.

In the end, there is one fundamental point on which we can fully concur with Professor Starcevic (2013) – let empiricism dictate how many (diagnostic) flowers should bloom and which should be nipped in the bud. In relation to the adult form of SAD, we believe that even though research is in its nascent stages, there are sufficient empirical grounds for psychiatrists to apply a diagnosis of SAD in adulthood. Our hunch is that adult SAD will cement its attachment to the diagnostic system and become an indispensable category in clinical practice. Let us not abandon adult SAD too readily.

See Commentary by Starcevic, 2013, 47(2): 188–189.