Standardized rating scales are an important tool to improve the assessment of psychopathological symptoms in terms of validity and reliability. Especially observer-rated scales are of primary importance in this respect. Self-rating scales can give a meaningful complementary view to the findings of observer-rated scales. Besides scales covering more or less the whole spectrum of psychopathological symptoms, specialised scales focussing only on symptoms of disorders like schizophrenia or depression were developed. They are widely used, specifically for pragmatic reasons.

It is increasingly recognised that major depressive disorder can be a chronic condition with many patients experiencing recurrent episodes. Remission from a depressive episode implies the absence or near absence of depressive symptoms. However, for many patients the periods between depressive episodes are not symptom free. Residual symptoms are predictors of relapse or recurrence, and may be associated with residual psychosocial impairment. In clinical studies, remission is commonly defined using a cut-off score on a rating scale for depressive symptoms, such as a score of < or = 7 on the 17-item Hamilton scale. However, there is debate about which scales and cut-offs are optimal and full-length rating scales are not widely used in clinical practice. In spite of such issues, it seems clear that a therapy should aim at the most complete remission possible. Unfortunately, recent studies have highlighted that in clinical practice usually only a low rate of remission is achieved. Although long-term treatment with antidepressants can reduce the risk of relapse or recurrence only a minority of patients in clinical practice achieve this as treatment is often prematurely stopped due to long-term side effects such as sleep disturbance, sexual dysfunctioning and weight gain. Therefore, it represents an unmet need to come up with antidepressant drugs of greater efficacy and improved tolerability as such treatments could lead to more complete remission in more patients.

The maintained antipsychotic efficacy of risperidone long-acting injectable (RLAI) was investigated in patients with schizophrenia or other psychoses who were transitioned directly from their previous antipsychotic medication. Patients symptomatically stable, but considered to require a treatment change, received 25 mg of RLAI (increased to 37.5 or 50 mg, if necessary) every 2 weeks for 6 months. Assessments included Positive and Negative Syndrome Scale (PANSS), Clinical Global Impression-Severity (CGI-S), Global Assessment of Functioning (GAF), SF-36 Health-Related Quality of Life Questionnaire and Extrapyramidal Symptoms Rating Scale (ESRS). Of 1876 patients enrolled, 74% completed the 6-month study. The most frequent reasons for treatment change were non-compliance (38%), insufficient efficacy (33%) and side-effects (26%). There was a significant reduction from baseline to endpoint in mean total PANSS score and in the scores on all PANSS subscales and symptom factors (P<0.001). CGI-S improved significantly, as did mean GAF score, all factors on the SF-36 and patient satisfaction with treatment. Scores on ESRS showed significant, sustained improvements throughout the study period. Direct initiation of RLAI was effective and well tolerated. RLAI provides an advancement in the treatment options available for a wide range of patients requiring long-term antipsychotic therapy.

The florid positive symptoms of schizophrenia (hallucinations, delusions, grossly disordered thinking) are often obvious. By comparison, negative symptoms (flattened affect, impoverished speech, apathy, avolition, anhedonia) are subtler and more difficult to recognize and diagnose. However, there is increasing recognition of the importance of negative symptoms in patients with schizophrenia. Secondary negative symptoms attributable to such factors as unrelieved positive symptoms, the adverse effects of antipsychotic pharmacotherapy, or social isolation may subside with resolution of such factors. In contrast, primary negative symptoms are an intrinsic aspect of schizophrenia; they are persistent and have been associated with poorer clinical outcomes. Although the lack of a reliably effective treatment for negative symptoms is a serious unmet need in this patient population, accurate diagnosis is still important. Assessment of suspected negative symptoms, using validated rating scales, can help to rule out comorbid affective or cognitive disorders that may mimic negative symptoms and to distinguish primary negative symptoms from potentially reversible secondary negative symptoms. This article reviews the definitions and classification of negative symptoms, compares the tools available for their assessment, and offers practical clinical algorithms for sorting through the differential diagnosis.

The PANSS (Positive and Negative Syndrome Scale) is one of the most important rating instruments for patients with schizophrenia. Nevertheless, there is a long and ongoing debate in the psychiatric community regarding its mathematical properties. All 30 items range from 1 to 7 leading to a minimum total score of 30, implying that the PANSS is an interval scale. For such interval scales straightforward calculation of relative changes is not appropriate. To calculate outcome criteria based on a percent change as, e.g., the widely accepted response criterion, the scale has to be transformed into a ratio scale beforehand. Recent publications have already pointed out the pitfall that ignoring the scale level (interval vs. ratio scale) leads to a set of mathematical problems, potentially resulting in erroneous results concerning the efficacy of the treatment. A Pubmed search based on the PRISMA statement of the highest-ranked psychiatric journals (search terms "PANSS" and "response") was carried out. All articles containing percent changes were included and methods of percent change calculation were analysed. This systematic literature research shows that the majority of authors (62%) actually appear to use incorrect calculations. In most instances the method of calculation was not described in the manuscript. These alarming results underline the need for standardized procedures for PANSS calculations.