Factor analysis of the scale of prodromal symptoms: differentiating between negative and depression symptoms.

BACKGROUND: This study examines the ability of the Scale of Prodromal Symptoms (SOPS) to differentiate between negative and depression symptoms in a young help-seeking ultrahigh risk (UHR) group. METHODS: SOPS data of 77 help-seeking patients at UHR for psychosis were analyzed with an exploratory factor analysis. The extracted Depression factor was validated with the Beck Depression Inventory (BDI). The extracted SOPS Negative symptoms factor was validated with the Negative symptoms subscale of the Positive and Negative Syndrome Scale (PANSS). RESULTS: Four factors were extracted from the SOPS: a negative, depression, disorganized and positive factor. The Negative symptom factor consisted of three items (N1: social anhedonia and withdrawal, N3: decreased expression of emotion; N4: decreased experience of emotions and self), and could be validated with the PANSS Negative symptoms subscale. The Depression factor was also made up of three items (G2: dysphoric mood, G4: impaired tolerance to normal stress, and D4: personal hygiene/social attentiveness), and could be validated with the BDI. CONCLUSIONS: Our results suggest that 3 items of the Negative symptoms subscale of the SOPS, 2 items of the General and 1 item of the Disorganization subscale differentiate validly between negative and depression symptoms in an UHR population.

Symptomatology and neuropsychological functioning in cannabis using subjects at ultra-high risk for developing psychosis and healthy controls.

OBJECTIVE: The relationship between cannabis use and psychosis has been studied intensively. Few data, however, are available on the relationship between cannabis use, ultra-high risk for developing psychosis and neurocognition. The aim of the present cross-sectional study was therefore to investigate the relationship between cannabis use, ultra-high-risk (UHR) symptoms and cognitive functioning in UHR patients and healthy controls. METHODS: A total of 63 ultra-high-risk patients (34 cannabis users) and 58 control subjects (28 cannabis users) were assessed with clinical measures and a neuropsychological test battery. Patients were eligible for the study if they were between the ages of 12 and 35 years and if they fell into one or more of the following inclusion groups: familial risk and reduced functioning, attenuated psychotic symptoms, brief limited intermittent psychotic symptoms and basic symptoms. Control subjects were eligible for the study if they were between the ages 12 and 35, had no present or past psychiatric illness, no family history of psychiatric illness, no drug use in the non-cannabis-using group, and use of at least four joints per week in the cannabis-using control group. RESULTS: In the UHR and the control group, cannabis users experienced more basic symptoms and UHR symptoms than the non-cannabis users. Moreover, cannabis users in the control group performed at the level of the UHR subjects on a test of verbal memory and verbal fluency. Frequency of cannabis use correlated with severity of several UHR symptoms. CONCLUSIONS: Cannabis-using UHR patients have more basic symptoms than non-using patients. In addition, healthy cannabis users have more subclinical UHR and basic symptoms and more neuropsychological dysfunctions than non-cannabis users. More frequent cannabis use was related to increased severity of certain UHR symptoms.