Early presence of thought disorder as a prospective sign of mental disorder

Stability of Thought Disorder Index among high-risk and low-risk adoptees in the Finnish adoptive family study of schizophrenia

The aim of the study was to evaluate whether thought disorders are stable, trait-like features specific to subjects who have a genetic liability to schizophrenia or a psychiatric disorder. The thought disorders of adoptees genetically at high risk (HR) or low risk (LR) for schizophrenia from the Finnish adoptive family study of schizophrenia were evaluated twice at a mean interval of 11 years, using the sum of the Thought Disorder Index (TDI) scores on the Rorschach (TDR). At the initial assessment, the mean TDR scores of women were significantly higher than those of men, while no association between genetic risk and psychiatric status or their interactions with the TDR scores at baseline were found. The main finding was that the initial TDR scores statistically significantly predicted the TDR scores at follow-up, thus indicating the stability of thought disorder over time. However, neither genetic or psychiatric status nor gender or any interaction between these variables associated with TDR at follow-up.

Differentiation of adoptees at high versus low genetic risk for schizophrenia by adjusted MMPI indices

The aim of this study was to find potential signs of genetic vulnerability to schizophrenia. The differences between adoptees at high genetic risk for schizophrenia (their biological mother had a schizophrenia spectrum disorder) and control adoptees of non-schizophrenia spectrum biological mothers were assessed. The comparisons between these groups were based on the Minnesota Multiphasic Personality Inventory (MMPI) test's subscale scores adjusted by gender, age at MMPI assessment, age at placement into the adoptive family and social class. The subjects were a subsamples of a total of 182 tested adoptees and 136 mentally healthy adoptees in the Finnish Adoptive Family Study. The high-risk group was found to be distinguishable from the low-risk group based on deviant scores on the Hostility, Hypomania and Lie scales. These scales may measure genetic vulnerability and also possibly be indicative of psychometric deviance predicting future onset of schizophrenia.

Rethinking Thought Disorder

It has been 30 years since Holzman introduced a special issue of the Schizophrenia Bulletin entitled “Thought Disorder in Schizophrenia.” He pointed out in his Editor’s Introduction that in contrast to the explosion of interest at that time in the biological aspects of schizophrenia, there were important areas of study that represented “... relatively neglected aspects of the psychopathology of schizophrenia, namely the varieties of thinking disorders (emphasis added) characteristic of schizophrenic patients and their possible underlying mechanisms.” Perhaps presciently, he ended his introduction by expressing hope that the articles included in that issue would lead to further intensive study of the cognitive (emphasis added) dysfunctions in schizophrenia. There has, indeed, been extensive research conducted in further understanding cognitive dysfunctions in schizophrenia, but considerably less so in understanding thought disorder.

Thought Disorder in Schizophrenia and Bipolar Disorder Probands, Their Relatives, and Nonpsychiatric Controls

Thought disorder (TD) has long been associated with schizophrenia (SZ) and is now widely recognized as a symptom of mania and other psychotic disorders as well. Previous studies have suggested that the TD found in the clinically unaffected relatives of SZ, schizoaffective and bipolar probands is qualitatively similar to that found in the probands themselves. Here, we examine which quantitative measures of TD optimize the distinction between patients with diagnoses of SZ and bipolar disorder with psychotic features (BP) from nonpsychiatric controls (NC) and from each other. In addition, we investigate whether these same TD measures also distinguish their respective clinically unaffected relatives (RelSZ, RelBP) from controls as well as from each other. We find that deviant verbalizations are significantly associated with SZ and are co-familial in clinically unaffected RelSZ, but are dissociated from, and are not co-familial for, BP disorder. In contrast, combinatory thinking was nonspecifically associated with psychosis, but did not aggregate in either group of relatives. These results provide further support for the usefulness of TD for identifying potential non-penetrant carriers of SZ-risk genes, in turn enhancing the power of genetic analyses. These findings also suggest that further refinement of the TD phenotype may be needed in order to be suitable for use in genetic studies of bipolar disorder.

The stability of severe thought disorders and mature thinking

The aim of this study was to investigate whether severe formal thought disorders and mature thinking are stable among adoptees (=187) drawn from the Finnish adoptive family study of schizophrenia. A group of 93 adoptees genetically at high risk (HR) and 94 at low risk (LR) for schizophrenia were assessed blindly and reliably using the Index of Primitive Thought (IPT) and the Index of Integration (IOI). Two assessments of the IPT and the IOI were performed with the mean interval of 11 years. Comparisons of the IPT and the IOI mean scores were conducted both at baseline and at follow-up between adoptees at low and high genetic risk, gender, and psychiatric status. The main result was that the IOI as well as the IPT of the adoptees at the initial assessment predicted the IOI and the IPT estimated at follow-up, thus indicating the stability of severe formal thought disorders and mature thinking over time. The stability of IOI or IPT was not related to genetic risk, gender or psychiatric status or their interactions.

Disorganization and reality distortion in schizophrenia: a meta-analysis of the relationship between positive symptoms and neurocognitive deficits

BACKGROUND

Factor analytic studies have shown that in schizophrenia patients, disorganization (e.g., conceptual disorganization and bizarre behavior) is a separate dimension from other types of positive symptoms such as reality distortion (delusions and hallucinations). Although some studies have found that disorganization is more strongly linked to neurocognitive deficits and poor functional outcomes than reality distortion, the findings are not always consistent.

METHODS

A meta-analysis of 104 studies (combined n=8015) was conducted to determine the magnitude of the relationship between neurocognition and disorganization as compared to reality distortion. Additional analyses were conducted to determine whether the strength of these relationships differed depending on the neurocognitive domain under investigation.

RESULTS

The relationship between reality distortion and neurocognition was weak (r=-.04; p=.03) as compared to the moderate association between disorganization and neurocognition (r=-.23; p<.01). In each of the six neurocognitive domains that were examined, disorganization was more strongly related to neurocognition (r's range from -.20 to -.26) than to reality distortion (r's range from .01 to -.12).

CONCLUSIONS

The effect size of the relationship between neurocognition and disorganization was significantly larger than the effect size of the relationship between neurocognition and reality distortion. These results hold across several neurocognitive domains. These findings support a dimensional view of positive symptoms distinguishing disorganization from reality distortion.

MMPI measures as signs of predisposition to mental disorder among adoptees at high risk for schizophrenia

The DSM-III-R diagnoses of a group of adoptees were predicted by the MMPI (Minnesota Multiphasic Personality Inventory) schizophrenia-related scales in the Finnish Adoptive Family Study. The sample consisted of 60 high-risk (HR) adopted-away offspring of biologic mothers with a diagnosis of broad schizophrenia spectrum and 76 low-risk (LR) control adoptees. They were assessed with the MMPI before the onset of any psychiatric disorder at a mean age of 24 years. High scores on the Psychopathic Deviate scale predicted psychiatric disorder at 11-year follow-up. Furthermore, LR adoptees', but not HR adoptees', mental disorders could be predicted with the MMPI scales Psychopathic Deviate and Golden-Meehl Indicators. These scales measure schizophrenia-related personality traits, including a social behavior, anhedonia, ambivalence, interpersonal aversiveness, and formal thought disturbances.

The schizophrenia prodrome: a developmentally informed review and update for psychopharmacologic treatment

In recent years substantial strides have been made in recognizing the prodrome for schizophrenia as a prospective entity in adolescents and young adults. Preliminary data suggest that atypical antipsychotic medications may improve symptoms and delay or prevent progression to schizophrenia, but substantial additional research is needed before the balance of long-term risks and benefits can be confidently assessed. Other medications or psychotherapies might benefit these patients as well. Some centers are beginning to examine if and how currently used prodromal diagnostic strategies and intervention studies might inform recognition and treatment of younger patients possibly prodromal for childhood-onset schizophrenia.

Determining the chronology and components of psychosis onset: The Nottingham Onset Schedule (NOS)

The Nottingham Onset Schedule (NOS) is a short, guided interview and rating schedule to measure onset in psychosis. Onset is defined as the time between the first reported/observed change in mental state/behaviour to the development of psychotic symptoms. Onset is conceptualised as comprising of (i) a prodrome of two parts: a period of 'unease' followed by 'non-diagnostic' symptoms; (ii) appearance of psychotic symptoms; and (iii) a build-up of diagnostic symptoms leading to a definite diagnosis. Twenty consecutive cases of first-episode psychosis were administered the NOS schedule to determine its psychometric properties including inter-rater and test-retest reliability. Its clinical and research potential as a reliable measure of duration of untreated psychosis (DUP) was assessed in a cohort of 99 cases of first-episode psychosis (56 schizophrenia, 43 affective psychoses). NOS identified all prodromal symptoms previously reported in other studies. There was high degree of inter-rater and test-retest reliability for all components of NOS. Duration of untreated psychosis was significantly longer (p<0.05) in schizophrenia (mean 179 days, S.D. 344; median 52 days) than in affective psychosis (mean 15 days, S.D. 116; median 12 days) but there were no gender differences between lengths of prodrome or treatment delays. The NOS provides a standardised and reliable way of recording early changes in psychosis and identifying relatively precise time points for measuring several durations in emerging psychosis. The scale is easy to use and is not time-consuming or labour intensive. Onset, as measured by NOS, is significantly longer in schizophrenic disorders than in affective psychosis. A small proportion of schizophrenia cases have very long DUP. Some cases with schizophrenia receive anti-psychotics in the prodromal phase, prior to the emergence of frank psychotic symptoms.

Thought disorder in patients with obsessive-compulsive disorder

We examined the presence of disordered thinking/perception in patients with obsessive-compulsive disorder (OCD). Recently, an obsession model has been proposed, which classifies obsessions into two different subtypes: autogenous obsessions and reactive obsessions (Lee & Kwon, 2003). Based on this model, we hypothesized that OCD patients primarily displaying autogenous obsessions as opposed to reactive obsessions would display more severely disordered thinking/perception. We compared 15 OCD patients primarily displaying autogenous obsessions (AOs), 14 OCD patients primarily displaying reactive obsessions (ROs), 32 patients with schizophrenia (SPRs), and 28 patients with other anxiety disorders (OADs) with respect to thought disorders as assessed by the Comprehensive System of the Rorschach Inkblot Test. Results indicated that both AOs and SPRs displayed more severe thought disorders compared to ROs or OADs. Theoretical and clinical implications are discussed.

Observing relationships in Finnish adoptive families: Oulu Family Rating Scale

Adoption studies were intended to separate genetic from environmental "causal" factors. In earlier adoption studies, psychiatric diagnostic labels for the adoptive parents were used as a proxy for the multiple dimensions of the family rearing environment. In the Finnish Adoption Study, research design provided the opportunity to study directly the adoptive family rearing environment. For this purpose 33 sub-scales were selected creating what we call Oulu Family Rating Scale (OPAS, Oulun PerheArviointiSkaala). In this paper, the manual for scoring of these sub-scales is presented.