What are the potential causes for schizophrenia?

Question

What will be an ideal response?

Answer 1

Schizophrenia is a very rare but serious mental disorder that affects between 0.3% and 0.7% of the population (APA, 2013). It is related to both structural and functional differences in many regions of the brain (Ren et al., 2013). Diagnosis requires two or more of the following symptoms: delusions (unrealistic, fixed beliefs such as that the CIA is trying to get you), hallucinations (most commonly, hearing voices that are not there), disorganized speech, very disorganized or catatonic behavior (lack of reaction to the environment), or negative symptoms (e.g., reduced expression of emotion and reduction in self-motivated behavior) which must be present for at least one month.. Symptoms often first appear in late adolescence, but the onset can be much later into the mid-30s (APA, 2013). In the very rare cases when children and younger teens develop this disorder, it is referred to as early-onset schizophrenia (McDonell & McClellan, 2007). However, although schizophrenia may not be diagnosed until adolescence, in many cases the disorder is preceded either by a gradual deterioration in social and cognitive functioning or by ongoing difficulties in these areas (Quee et al., 2014). After the symptoms of schizophrenia develop, functioning in these areas continues to decline, resulting in difficulty with social, academic, and occupational functioning (Tandon et al., 2013; McClellan & Stocker, 2013). 
Although we do not understand all the causes of schizophrenia, it is clear that genes play a large role, as shown by research with twins. If one identical twin is schizophrenic, there is a 40% to 60% chance the other will be as well, while a fraternal twin has only 5% to 15% chance of sharing this condition with a twin (McClellan & Stocker, 2013). Prenatal disruption of brain development by factors such as the mother's experience of starvation or influenza increases the possibility the child will develop schizophrenia (Brown & Susser, 2008; Limosin, Rouillon, Payan, Cohen, & Strub, 2003), as does early head injuries for those with a genetic vulnerability (AbdelMalik, Husten, Chow, & Bassett, 2003). There also is a growing body of evidence that adolescent marijuana use can increase the risk of schizophrenia for some teens who are more vulnerable to the disorder because of genetic predisposition, a dysfunctional environment, and other factors that are not yet entirely clear. For this reason, parents, teachers and health-care providers should be aware of the possibility and look for a decline in school performance and odd behavior in teens who are using marijuana (Evins, Green, Kane & Murray, 2012).