Differences between schizophrenia and schizoaffective disorder

Psychotic spectrum disorders have always generated interest among mental health professionals. Perhaps because of its particular and shocking symptoms, such as little or no contact with reality, or the appearance of delusions and hallucinations. Today we will talk about the differences between schizophrenia and schizoaffective disorder, two disorders on this spectrum that, although they may seem similar, present notable differences.

On the one hand, in schizophrenia, positive symptoms (delusions, hallucinations…) and negative symptoms (avolition, anhedonia…) appear. In the case of schizoaffective disorder, psychotic symptoms are combined with mood symptoms (these have more weight than in schizophrenia). In fact, to make such a diagnosis it is essential that at least 2 weeks pass without significant emotional symptoms, but with the presence of delusions or hallucinations.

Although it is true that many authors consider schizoaffective disorder independent of schizophrenia, others believe that it is a variant of it and others think that it is a transitional state between schizophrenia and mood disorders.

As we see, it is a controversial disorder, but the current DSM-5 (2014) (Diagnostic and Statistical Manual of Mental Disorders) considers both disorders as independent diagnostic categories.

Differences between schizophrenia and schizoaffective disorder

What differences between schizophrenia and schizoaffective disorder can we find? These refer to many of the characteristics of both disorders: symptoms, prevalence, duration… We will tell you about them in detail in the following sections!

Prevalence

One of the differences between schizophrenia and schizoaffective disorder is their prevalence; So, The prevalence of schizophrenia is 0.3-0.7% of the population (according to data from the DSM-5; the DSM-IV-TR spoke of a slightly higher prevalence, 1%).

On the other hand, according to the WHO, schizophrenia affects 12 million men in the world, and 9 million women; The organism also adds that it appears earlier in men.

Instead, schizoaffective disorder is much less common, and only appears in 0.3% of the population. These data are also extracted from the DSM-5 and from research carried out by a team from the University of Hong Kong in 2017.

Start

Regarding the onset or origin of the disorder, in the case of schizophrenia it is usually insidious, while in schizoaffective it is usually acute. That is to say, Schizophrenia generally begins progressively, while schizoaffective disorder usually begins more abruptly.. However, that does not mean that this rule is followed in all cases.

Forecast

The prognosis of schizophrenia is worse than that of schizoaffective disorder. In this sense, schizophrenia tends to be more disabling and interfere more with the person’s daily functioning than schizoaffective disorder.

On the other hand, and as an added fact, if we compare schizoaffective disorder with mood disorders (depression or bipolar disorder), we know that it has a worse prognosis.

Duration

Another difference between schizophrenia and schizoaffective disorder has to do with their duration (more specifically, with their duration criteria in the DSM-5). As for schizophrenia, according to the manual, its characteristic symptoms (hallucinations, delusional ideas, disorganized language…) must last at least 1 month (or less if they have been successfully treated). In addition to these symptoms, continuous signs of alteration must appear in the person for at least 6 months.

This differs from schizoaffective disorder, since in this disorder the monthly criterion is maintained, but not the 6-month criterion. On the other hand, Added to this disorder is the fact that there must necessarily be 2 weeks without notable affective symptoms (psychotic symptoms).. This last criterion does not appear in the diagnosis of schizophrenia.

Mood episodes or disorders

Mood alterations are related to these two psychotic disorders, But in what way? In the case of schizophrenia, in order to be diagnosed with such a disorder, according to the DSM-5, mood disorders (depression, bipolar disorder…) must never appear, since this would exclude its diagnosis. Nor can a schizoaffective disorder appear.

However, In the case of schizoaffective disorder, it is necessary for mood symptoms (alterations) to appear. Such symptoms include major depressive episodes or manic episodes.

Affective symptoms

In the previous section we talked about mood episodes and disorders, but here we will focus only on the affective symptoms that do not constitute a disorder or an episode: anhedonia, sadness, mania, euphoria, etc.

So, Affective symptoms become very relevant in schizoaffective disorder (in fact, it is necessary for these to appear for the disorder to be diagnosed).

On the other hand, in the case of schizophrenia, affective symptoms are not necessary for a diagnosis to be made (although they may appear). In fact, People with schizophrenia usually present the so-called symptoms negativeincluding: flattened affect, avolition, depressive symptoms, restricted emotional expression, etc.

Subtypes

Another difference between schizophrenia and schizoaffective disorder refers to the subtypes of each disorder. Schizophrenia no longer has subtypes in the latest edition of the DSM (in the DSM-IV-TR, the following subtypes did exist: paranoid, catatonic, disorganized, undifferentiated and residual). In addition, the subtype of simple schizophrenia was added to the ICD-10.

However, Schizoaffective disorder does include subtypes in the DSM-5. They are bipolar type or depressive type:

Bipolar type: the disorder includes some manic episode. Depressive type: the disorder includes major depressive episodes.

Other symptoms

Finally, the last difference between schizophrenia and schizoaffective disorder has to do with the appearance of other symptoms, that appear more frequently in schizophrenia, and which are the following:

Auditory hallucinations. Affective flattening (affective symptom). Disorganization of thought. Poverty of language.

Instead, Confusion is a symptom that appears more in schizoaffective disorder than in schizophrenia (where it appears very little).

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