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Saturday Journal Club.

On a technical note, the main statistician program I use — R — is available for any post FreeBSD version or fork. I am still using Fedora on my main working machines at home (and, sadly, MacOS at work) but this may mean that there is an alternative.

But it is Saturday, so what is going on in research that is open source this week? Let’s start with a differentiation in suicide rates — and timing — by immigration status. It not only matters where you are from, but in the second generation how your parents married. If you formed a family elsewhere with a Norwegian and then moved, the children have a higher risk of suicide similar to that of natives, but if your parents were married in Norway and one is born there, the risk is normalized.

Considering both sexes, the suicide mortality rate (per 100,000 population) was 12.22 for native Norwegians, 9.53 for first-generation immigrants, 2.56 for second-generation immigrants, 11.13 for Norwegian-born with one foreign-born parent, and 17.10 for foreign-born with at least one Norwegian-born parent (Table 1).

The suicide rate of first-generation immigrants was significantly lower than that of native Norwegians (9.53 vs 12.22, P < 0.01). This difference remained statistically significant only among males (12.73 vs 18.03, P < 0.01) and not among females (6.29 vs 6.54, P = 0.56).Second-generation immigrants showed very low suicide rates in both sexes (3.99 in males and 1.05 in females), but these estimates should be interpreted with caution because second-generation immigrants represent a relatively younger group of people in this society (see Discussion).No statistically significant differences were observed in suicide rates between Norwegian-born with one foreign-born parent and native Norwegians (15.70 vs 18.03 in males, P = 0.06; 6.21 vs 6.54 in females, P = 0.67). Foreign-born persons with at least one Norwegian-born parent had, however, significantly higher suicide rates than the natives, for both sexes (22.42 vs 18.03 in males, P < 0.01; 11.67 vs 6.54 in females, P < 0.01).Puzo Q, Mehlum L, Qin P (2018) Rates and characteristics of suicide by immigration background in Norway. PLoS ONE 13(9): e0205035. https://doi.org/10.1371/journal.pone.0205035

Norway is not part of the EU. It has tight rules on immigration and strong social cohesion. This may matter. The paper is an example of the type of research needed, but all to often left undone.

A more interesting approach has been taken by the Maudsley, using machine learning to ascertain from a large computerized database people with tactile, olfactory and gustatory hallucinations. These have been described in people using “Z” drugs — zopiclone, zopilodem and others — and indeed the authors found an association, but discounted the much larger association with a diagnosis of psychosis or a mood disorder. Since hallucinations are not uncommon in mood disorders or psychosis (and Z drugs are often used in this group).

It is worth noting that these drugs are not without side effects.

What else? An Israeli group tries to understand why psychiatrists disagree about diagnosis, thinking that DSM criteria have validity. And misses the point: they do not. The analogy I use is that the DSM is criteria designed to distinguish the boundary of a field or category — akin to the fence around a field. It does not describe what is in the field.

And the categorical system does not deal very well with population issues. An editorial in JAMA shows this, looking at an intervention in children from Romania who had been neglected. I will leave the ethics of randomization of high quality foster care to one side: there is never enough high quality foster care in any society.

For outcomes, the authors factor-analyzed parent- and teacher-reported measures of psychopathology that were administered at ages 8, 12, and 16 years to determine a continuous latent factor that represented general psychopathology (the “P-factor”), as well as 2 residual factors that represented variance in internalizing and externalizing symptoms not accounted for by this general factor. This approach aligns with recent research on the structure of psychopathology, which indicates that (1) psychiatric disorders are dimensional constructs rather than discrete categorical entities, and (2) individuals who meet the criteria for 1 disorder typically also meet criteria for others, both cross-sectionally and across the life course.2 Latent growth models were used to test for between-group differences in these outcomes at each age, as well as the differences in the rate at which they changed over time.

As expected, never-institutionalized children reported significantly fewer symptoms of psychopathology than both previously institutionalized groups. However, children who were randomized to early foster care experienced declines in general psychopathology and residual externalizing symptoms throughout adolescence, whereas the symptoms for children randomized to care as usual remained stably high or increased. As a result, children raised in foster care scored significantly lower than children who received care as usual on both factor scores at ages 12 and 16 years, indicating a beneficial intervention effect on both general psychopathology and residual externalizing symptoms in adolescence.

These analyses by Wade and colleagues1 join a growing literature indicating that nonspecific associations between adverse experiences and psychiatric disorder may be the rule rather than the exception. Indeed, research on exposures as diverse as child maltreatment, the terrorist attack on September 11, 2001, armed combat, and perceived discrimination has indicated that these experiences are associated with broad, general increases in psychopathology (eg, internalizing and externalizing symptoms) rather than increased rates of specific disorders or clusters of symptoms

Schaefer JD. Use of Hierarchical Measures of Psychopathology to Capture the Long (and Wide) Shadow of Early Deprivation in the Bucharest Early Intervention Project Analysis. JAMA Psychiatry. Published online September 26, 2018. doi:10.1001/jamapsychiatry.2018.2215

Phenomenology is an epiphenonema. The underling neural networks that drive this are mutable: otherwise treatments would not work. To be confident that you know what the root cause is to show you are ignorant.

If you are wise you accept this. If, however, you are provincial, then, like an underemployed Viennese neurologist, you invent theories.

Don’t be like that: Freud was more wrong than Kraepelin ever was.

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