Relationship Between Anxiety And Depression With Schizophrenia

Abstract

The extent to which cognitive abilities decline over age depends on a lot of different factors and varies considerably between individuals. Among these factors are depression, anxiety and significant life events (SLE's) as possible predictors of individual differences in cognitive aging. The objective is to investigate the effects of depression and anxiety on cognitive decline and to investigate the role of significant life events in depression, anxiety and cognitive decline. SLE's were investigated as a predictor for depression and anxiety and for cognitive impairment and cognitive decline as well. Results In the first experiment, participants with an anxiety or depressive disorder did not significantly differ from control subjects on measures of cognitive impairment, cognitive decline, or SLE's. In the second experiment, depressive and anxious symptoms had no significant effect on cognitive decline, but there was a significant effect of anxious symptoms on measures of speed and interference cross-sectionally.

Relationship between Anxiety and Depression with Schizophrenia

Introduction

In recent research it is well established that during aging, not only physical abilities generally decline, but cognitive abilities as well. However, the extent to which these cognitive abilities decline over age varies considerably between individuals. Almost one in every four elderly people, for example, suffers from serious cognitive decline, which is a major risk factor for later development of dementia (Unverzagt et al., 2001). Since the number of elderly people will continue to grow steadily, cognitive decline leading to dementia is likely to become one of the most important medical conditions (Park, O'Connell & Thomson, 2004).

It is therefore important to consider which factors can influence individual differences in normal cognitive aging, in order to increase our knowledge of the mechanisms by which cognitive decline occurs. In the literature, individual-difference factors such as life-style (e.g. social activity, exercise), genetics (e.g. the APOE-e4 allele), health-related variables (e.g. vitamin B deficiency, thyroid disturbance, circulatory disease, diabetes) and personality traits (e.g. neuroticism) have been mentioned (Bäckman, 2004; Rosnick, Small, McEvoy, Borenstein and Mortimer, 2007; Wilson et al., 2006). Three other factors which are thought to influence cognitive decline, namely depression, anxiety and the experience of significant life events will be discussed in more detail below.

The relationship between psychotic and affective symptoms has been central to the dilemma of psychiatric classification. Indeed, substantial evidence (not reviewed here) show that schizophrenia and bipolar disorder, in particular, may be distributed across a dimensional spectrum (or more apt, across multidimensional spectra). Furthermore, there has been an ongoing and robust debate about the nosological status of "schizoaffective" disorder with varying definitions and approaches that make that literature very difficult to negotiate.

These 2 aspects go way beyond the scope of this review yet are important aspects of nosology that are of relevance to the topic of psychiatric comorbidity. Here, we confine ourselves to reviewing studies of the co-occurrence of the symptoms of psychosis and unipolar depression, a phenomenon seen at some point in illness in the majority of schizophrenia sufferers, as well as in a substantial number ...